linux/drivers/usb/serial/usb-serial.c

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/*
* USB Serial Converter driver
*
* Copyright (C) 1999 - 2005 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2000 Peter Berger (pberger@brimson.com)
* Copyright (C) 2000 Al Borchers (borchers@steinerpoint.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This driver was originally based on the ACM driver by Armin Fuerst (which was
* based on a driver by Brad Keryan)
*
* See Documentation/usb/usb-serial.txt for more information on using this
* driver
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/uaccess.h>
#include <linux/serial.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/kfifo.h>
#include "pl2303.h"
/*
* Version Information
*/
#define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com, http://www.kroah.com/linux/"
#define DRIVER_DESC "USB Serial Driver core"
/* Driver structure we register with the USB core */
static struct usb_driver usb_serial_driver = {
.name = "usbserial",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.suspend = usb_serial_suspend,
.resume = usb_serial_resume,
.no_dynamic_id = 1,
.supports_autosuspend = 1,
};
/* There is no MODULE_DEVICE_TABLE for usbserial.c. Instead
the MODULE_DEVICE_TABLE declarations in each serial driver
cause the "hotplug" program to pull in whatever module is necessary
via modprobe, and modprobe will load usbserial because the serial
drivers depend on it.
*/
static int debug;
/* initially all NULL */
static struct usb_serial *serial_table[SERIAL_TTY_MINORS];
static DEFINE_MUTEX(table_lock);
static LIST_HEAD(usb_serial_driver_list);
/*
* Look up the serial structure. If it is found and it hasn't been
* disconnected, return with its disc_mutex held and its refcount
* incremented. Otherwise return NULL.
*/
struct usb_serial *usb_serial_get_by_index(unsigned index)
{
struct usb_serial *serial;
mutex_lock(&table_lock);
serial = serial_table[index];
if (serial) {
mutex_lock(&serial->disc_mutex);
if (serial->disconnected) {
mutex_unlock(&serial->disc_mutex);
serial = NULL;
} else {
kref_get(&serial->kref);
}
}
mutex_unlock(&table_lock);
return serial;
}
static struct usb_serial *get_free_serial(struct usb_serial *serial,
int num_ports, unsigned int *minor)
{
unsigned int i, j;
int good_spot;
dbg("%s %d", __func__, num_ports);
*minor = 0;
mutex_lock(&table_lock);
for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
if (serial_table[i])
continue;
good_spot = 1;
for (j = 1; j <= num_ports-1; ++j)
if ((i+j >= SERIAL_TTY_MINORS) || (serial_table[i+j])) {
good_spot = 0;
i += j;
break;
}
if (good_spot == 0)
continue;
*minor = i;
j = 0;
dbg("%s - minor base = %d", __func__, *minor);
for (i = *minor; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i) {
serial_table[i] = serial;
serial->port[j++]->number = i;
}
mutex_unlock(&table_lock);
return serial;
}
mutex_unlock(&table_lock);
return NULL;
}
static void return_serial(struct usb_serial *serial)
{
int i;
dbg("%s", __func__);
mutex_lock(&table_lock);
for (i = 0; i < serial->num_ports; ++i)
serial_table[serial->minor + i] = NULL;
mutex_unlock(&table_lock);
}
static void destroy_serial(struct kref *kref)
{
struct usb_serial *serial;
struct usb_serial_port *port;
int i;
serial = to_usb_serial(kref);
dbg("%s - %s", __func__, serial->type->description);
/* return the minor range that this device had */
if (serial->minor != SERIAL_TTY_NO_MINOR)
return_serial(serial);
if (serial->attached)
serial->type->release(serial);
/* Now that nothing is using the ports, they can be freed */
for (i = 0; i < serial->num_port_pointers; ++i) {
port = serial->port[i];
if (port) {
port->serial = NULL;
put_device(&port->dev);
}
}
usb_put_dev(serial->dev);
kfree(serial);
}
void usb_serial_put(struct usb_serial *serial)
{
kref_put(&serial->kref, destroy_serial);
}
/*****************************************************************************
* Driver tty interface functions
*****************************************************************************/
/**
* serial_install - install tty
* @driver: the driver (USB in our case)
* @tty: the tty being created
*
* Create the termios objects for this tty. We use the default
* USB serial settings but permit them to be overridden by
* serial->type->init_termios.
*
* This is the first place a new tty gets used. Hence this is where we
* acquire references to the usb_serial structure and the driver module,
* where we store a pointer to the port, and where we do an autoresume.
tty: Fix regressions caused by commit b50989dc The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox <alan@linux.intel.com> Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young <hidave.darkstar@gmail.com> [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 18:00:42 +02:00
* All these actions are reversed in serial_cleanup().
*/
static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
{
int idx = tty->index;
struct usb_serial *serial;
struct usb_serial_port *port;
int retval = -ENODEV;
dbg("%s", __func__);
serial = usb_serial_get_by_index(idx);
if (!serial)
return retval;
port = serial->port[idx - serial->minor];
if (!port)
goto error_no_port;
if (!try_module_get(serial->type->driver.owner))
goto error_module_get;
/* perform the standard setup */
retval = tty_init_termios(tty);
if (retval)
goto error_init_termios;
retval = usb_autopm_get_interface(serial->interface);
if (retval)
goto error_get_interface;
mutex_unlock(&serial->disc_mutex);
/* allow the driver to update the settings */
if (serial->type->init_termios)
serial->type->init_termios(tty);
tty->driver_data = port;
/* Final install (we use the default method) */
tty_driver_kref_get(driver);
tty->count++;
driver->ttys[idx] = tty;
return retval;
error_get_interface:
error_init_termios:
module_put(serial->type->driver.owner);
error_module_get:
error_no_port:
usb_serial_put(serial);
mutex_unlock(&serial->disc_mutex);
return retval;
}
static int serial_activate(struct tty_port *tport, struct tty_struct *tty)
{
struct usb_serial_port *port =
container_of(tport, struct usb_serial_port, port);
struct usb_serial *serial = port->serial;
int retval;
USB: serial: refuse to open recently removed USB Serial devices A USB-serial converter device is plugged into a system, and a process opens it's device node. If the device is physically removed whilst the process still has its device node open, then other processes can sucessfully open the now non-existent device's node. I would expect that open() on a device that has been physically removed should return ENODEV. This is manifesting itself with getty on my system. I do the following: 1. set up inittab to spawn getty on ttyUSB0, eg: T1:23:respawn:/sbin/getty -L ttyUSB0 115200 vt100 2. Plug in USB-serial converter cable 3. Wait for a login prompt on a terminal program attached to the serial cable 4. Login 5. Pull the USB-serial converter cable from the box 6. getty doesn't realise that ttyUSB0 no longer exists as /dev/ttyUSB0 can still be opened. 7. Re-insert the USB-serial converter cable 8. You should no longer get a login prompt over the serial cable, as the the USB-serial cable now shows up as /dev/ttyUSB1, and getty is trying to talk to /dev/ttyUSB0. The attached patch will cause open("/dev/ttyUSB0", O_RDONLY) to return ENODEV after the USB-serial converter has been pulled. The patch was created against 2.6.28.1. I can supply it against something else if needs be. It is fairly simple, so should be OK. I am using a pl2303 device, although I don't think that makes any difference. From: James Woodcock <James.Woodcock@ACULAB.COM> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-11 16:06:53 +01:00
mutex_lock(&serial->disc_mutex);
if (serial->disconnected)
retval = -ENODEV;
else
retval = port->serial->type->open(tty, port);
mutex_unlock(&serial->disc_mutex);
return retval;
}
static int serial_open(struct tty_struct *tty, struct file *filp)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
return tty_port_open(&port->port, tty, filp);
}
/**
* serial_down - shut down hardware
* @tport: tty port to shut down
*
* Shut down a USB serial port unless it is the console. We never
* shut down the console hardware as it will always be in use. Serialized
* against activate by the tport mutex and kept to matching open/close pairs
* of calls by the ASYNCB_INITIALIZED flag.
*/
static void serial_down(struct tty_port *tport)
{
struct usb_serial_port *port =
container_of(tport, struct usb_serial_port, port);
struct usb_serial_driver *drv = port->serial->type;
/*
* The console is magical. Do not hang up the console hardware
* or there will be tears.
*/
if (port->port.console)
return;
if (drv->close)
drv->close(port);
}
static void serial_hangup(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
tty_port_hangup(&port->port);
}
static void serial_close(struct tty_struct *tty, struct file *filp)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
tty_port_close(&port->port, tty, filp);
}
/**
tty: Fix regressions caused by commit b50989dc The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox <alan@linux.intel.com> Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young <hidave.darkstar@gmail.com> [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 18:00:42 +02:00
* serial_cleanup - free resources post close/hangup
* @port: port to free up
*
* Do the resource freeing and refcount dropping for the port.
* Avoid freeing the console.
*
tty: Fix regressions caused by commit b50989dc The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox <alan@linux.intel.com> Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young <hidave.darkstar@gmail.com> [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 18:00:42 +02:00
* Called asynchronously after the last tty kref is dropped,
* and the tty layer has already done the tty_shutdown(tty);
*/
tty: Fix regressions caused by commit b50989dc The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox <alan@linux.intel.com> Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young <hidave.darkstar@gmail.com> [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 18:00:42 +02:00
static void serial_cleanup(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct usb_serial *serial;
struct module *owner;
/* The console is magical. Do not hang up the console hardware
* or there will be tears.
*/
if (port->port.console)
return;
dbg("%s - port %d", __func__, port->number);
tty->driver_data = NULL;
serial = port->serial;
owner = serial->type->driver.owner;
mutex_lock(&serial->disc_mutex);
if (!serial->disconnected)
usb_autopm_put_interface(serial->interface);
mutex_unlock(&serial->disc_mutex);
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
usb_serial_put(serial);
module_put(owner);
}
static int serial_write(struct tty_struct *tty, const unsigned char *buf,
int count)
{
struct usb_serial_port *port = tty->driver_data;
int retval = -ENODEV;
if (port->serial->dev->state == USB_STATE_NOTATTACHED)
goto exit;
dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
/* pass on to the driver specific version of this function */
retval = port->serial->type->write(tty, port, buf, count);
exit:
return retval;
}
static int serial_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
/* pass on to the driver specific version of this function */
return port->serial->type->write_room(tty);
}
static int serial_chars_in_buffer(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
/* if the device was unplugged then any remaining characters
fell out of the connector ;) */
if (port->serial->disconnected)
return 0;
/* pass on to the driver specific version of this function */
return port->serial->type->chars_in_buffer(tty);
}
static void serial_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
/* pass on to the driver specific version of this function */
if (port->serial->type->throttle)
port->serial->type->throttle(tty);
}
static void serial_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
/* pass on to the driver specific version of this function */
if (port->serial->type->unthrottle)
port->serial->type->unthrottle(tty);
}
static int serial_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg)
{
struct usb_serial_port *port = tty->driver_data;
int retval = -ENODEV;
dbg("%s - port %d, cmd 0x%.4x", __func__, port->number, cmd);
/* pass on to the driver specific version of this function
if it is available */
if (port->serial->type->ioctl) {
retval = port->serial->type->ioctl(tty, cmd, arg);
} else
retval = -ENOIOCTLCMD;
return retval;
}
static void serial_set_termios(struct tty_struct *tty, struct ktermios *old)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
/* pass on to the driver specific version of this function
if it is available */
if (port->serial->type->set_termios)
port->serial->type->set_termios(tty, port, old);
else
tty_termios_copy_hw(tty->termios, old);
}
static int serial_break(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
/* pass on to the driver specific version of this function
if it is available */
if (port->serial->type->break_ctl)
port->serial->type->break_ctl(tty, break_state);
return 0;
}
static int serial_proc_show(struct seq_file *m, void *v)
{
struct usb_serial *serial;
int i;
char tmp[40];
dbg("%s", __func__);
seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
serial = usb_serial_get_by_index(i);
if (serial == NULL)
continue;
seq_printf(m, "%d:", i);
if (serial->type->driver.owner)
seq_printf(m, " module:%s",
module_name(serial->type->driver.owner));
seq_printf(m, " name:\"%s\"",
serial->type->description);
seq_printf(m, " vendor:%04x product:%04x",
le16_to_cpu(serial->dev->descriptor.idVendor),
le16_to_cpu(serial->dev->descriptor.idProduct));
seq_printf(m, " num_ports:%d", serial->num_ports);
seq_printf(m, " port:%d", i - serial->minor + 1);
usb_make_path(serial->dev, tmp, sizeof(tmp));
seq_printf(m, " path:%s", tmp);
seq_putc(m, '\n');
usb_serial_put(serial);
mutex_unlock(&serial->disc_mutex);
}
return 0;
}
static int serial_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, serial_proc_show, NULL);
}
static const struct file_operations serial_proc_fops = {
.owner = THIS_MODULE,
.open = serial_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int serial_tiocmget(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
if (port->serial->type->tiocmget)
return port->serial->type->tiocmget(tty);
return -EINVAL;
}
static int serial_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
if (port->serial->type->tiocmset)
return port->serial->type->tiocmset(tty, set, clear);
return -EINVAL;
}
static int serial_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount)
{
struct usb_serial_port *port = tty->driver_data;
dbg("%s - port %d", __func__, port->number);
if (port->serial->type->get_icount)
return port->serial->type->get_icount(tty, icount);
return -EINVAL;
}
/*
* We would be calling tty_wakeup here, but unfortunately some line
* disciplines have an annoying habit of calling tty->write from
* the write wakeup callback (e.g. n_hdlc.c).
*/
void usb_serial_port_softint(struct usb_serial_port *port)
{
schedule_work(&port->work);
}
EXPORT_SYMBOL_GPL(usb_serial_port_softint);
static void usb_serial_port_work(struct work_struct *work)
{
struct usb_serial_port *port =
container_of(work, struct usb_serial_port, work);
struct tty_struct *tty;
dbg("%s - port %d", __func__, port->number);
tty = tty_port_tty_get(&port->port);
if (!tty)
return;
tty_wakeup(tty);
tty_kref_put(tty);
}
static void kill_traffic(struct usb_serial_port *port)
{
int i;
usb_kill_urb(port->read_urb);
usb_kill_urb(port->write_urb);
for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
usb_kill_urb(port->write_urbs[i]);
/*
* This is tricky.
* Some drivers submit the read_urb in the
* handler for the write_urb or vice versa
* this order determines the order in which
* usb_kill_urb() must be used to reliably
* kill the URBs. As it is unknown here,
* both orders must be used in turn.
* The call below is not redundant.
*/
usb_kill_urb(port->read_urb);
usb_kill_urb(port->interrupt_in_urb);
usb_kill_urb(port->interrupt_out_urb);
}
static void port_release(struct device *dev)
{
struct usb_serial_port *port = to_usb_serial_port(dev);
int i;
dbg ("%s - %s", __func__, dev_name(dev));
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
/*
* Stop all the traffic before cancelling the work, so that
* nobody will restart it by calling usb_serial_port_softint.
*/
kill_traffic(port);
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
cancel_work_sync(&port->work);
usb_free_urb(port->read_urb);
usb_free_urb(port->write_urb);
usb_free_urb(port->interrupt_in_urb);
usb_free_urb(port->interrupt_out_urb);
for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
usb_free_urb(port->write_urbs[i]);
kfree(port->bulk_out_buffers[i]);
}
kfifo_free(&port->write_fifo);
kfree(port->bulk_in_buffer);
kfree(port->bulk_out_buffer);
kfree(port->interrupt_in_buffer);
kfree(port->interrupt_out_buffer);
kfree(port);
}
static struct usb_serial *create_serial(struct usb_device *dev,
struct usb_interface *interface,
struct usb_serial_driver *driver)
{
struct usb_serial *serial;
serial = kzalloc(sizeof(*serial), GFP_KERNEL);
if (!serial) {
dev_err(&dev->dev, "%s - out of memory\n", __func__);
return NULL;
}
serial->dev = usb_get_dev(dev);
serial->type = driver;
serial->interface = interface;
kref_init(&serial->kref);
mutex_init(&serial->disc_mutex);
serial->minor = SERIAL_TTY_NO_MINOR;
return serial;
}
static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
struct usb_serial_driver *drv)
{
struct usb_dynid *dynid;
spin_lock(&drv->dynids.lock);
list_for_each_entry(dynid, &drv->dynids.list, node) {
if (usb_match_one_id(intf, &dynid->id)) {
spin_unlock(&drv->dynids.lock);
return &dynid->id;
}
}
spin_unlock(&drv->dynids.lock);
return NULL;
}
static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
struct usb_interface *intf)
{
const struct usb_device_id *id;
id = usb_match_id(intf, drv->id_table);
if (id) {
dbg("static descriptor matches");
goto exit;
}
id = match_dynamic_id(intf, drv);
if (id)
dbg("dynamic descriptor matches");
exit:
return id;
}
/* Caller must hold table_lock */
static struct usb_serial_driver *search_serial_device(
struct usb_interface *iface)
{
const struct usb_device_id *id;
struct usb_serial_driver *drv;
/* Check if the usb id matches a known device */
list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
id = get_iface_id(drv, iface);
if (id)
return drv;
}
return NULL;
}
static int serial_carrier_raised(struct tty_port *port)
{
struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
struct usb_serial_driver *drv = p->serial->type;
if (drv->carrier_raised)
return drv->carrier_raised(p);
/* No carrier control - don't block */
return 1;
}
static void serial_dtr_rts(struct tty_port *port, int on)
{
struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
struct usb_serial_driver *drv = p->serial->type;
if (drv->dtr_rts)
drv->dtr_rts(p, on);
}
static const struct tty_port_operations serial_port_ops = {
.carrier_raised = serial_carrier_raised,
.dtr_rts = serial_dtr_rts,
.activate = serial_activate,
.shutdown = serial_down,
};
int usb_serial_probe(struct usb_interface *interface,
const struct usb_device_id *id)
{
struct usb_device *dev = interface_to_usbdev(interface);
struct usb_serial *serial = NULL;
struct usb_serial_port *port;
struct usb_host_interface *iface_desc;
struct usb_endpoint_descriptor *endpoint;
struct usb_endpoint_descriptor *interrupt_in_endpoint[MAX_NUM_PORTS];
struct usb_endpoint_descriptor *interrupt_out_endpoint[MAX_NUM_PORTS];
struct usb_endpoint_descriptor *bulk_in_endpoint[MAX_NUM_PORTS];
struct usb_endpoint_descriptor *bulk_out_endpoint[MAX_NUM_PORTS];
struct usb_serial_driver *type = NULL;
int retval;
unsigned int minor;
int buffer_size;
int i;
int num_interrupt_in = 0;
int num_interrupt_out = 0;
int num_bulk_in = 0;
int num_bulk_out = 0;
int num_ports = 0;
int max_endpoints;
mutex_lock(&table_lock);
type = search_serial_device(interface);
if (!type) {
mutex_unlock(&table_lock);
dbg("none matched");
return -ENODEV;
}
if (!try_module_get(type->driver.owner)) {
mutex_unlock(&table_lock);
dev_err(&interface->dev, "module get failed, exiting\n");
return -EIO;
}
mutex_unlock(&table_lock);
serial = create_serial(dev, interface, type);
if (!serial) {
module_put(type->driver.owner);
dev_err(&interface->dev, "%s - out of memory\n", __func__);
return -ENOMEM;
}
/* if this device type has a probe function, call it */
if (type->probe) {
const struct usb_device_id *id;
id = get_iface_id(type, interface);
retval = type->probe(serial, id);
if (retval) {
dbg("sub driver rejected device");
kfree(serial);
module_put(type->driver.owner);
return retval;
}
}
/* descriptor matches, let's find the endpoints needed */
/* check out the endpoints */
iface_desc = interface->cur_altsetting;
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
endpoint = &iface_desc->endpoint[i].desc;
if (usb_endpoint_is_bulk_in(endpoint)) {
/* we found a bulk in endpoint */
dbg("found bulk in on endpoint %d", i);
bulk_in_endpoint[num_bulk_in] = endpoint;
++num_bulk_in;
}
if (usb_endpoint_is_bulk_out(endpoint)) {
/* we found a bulk out endpoint */
dbg("found bulk out on endpoint %d", i);
bulk_out_endpoint[num_bulk_out] = endpoint;
++num_bulk_out;
}
if (usb_endpoint_is_int_in(endpoint)) {
/* we found a interrupt in endpoint */
dbg("found interrupt in on endpoint %d", i);
interrupt_in_endpoint[num_interrupt_in] = endpoint;
++num_interrupt_in;
}
if (usb_endpoint_is_int_out(endpoint)) {
/* we found an interrupt out endpoint */
dbg("found interrupt out on endpoint %d", i);
interrupt_out_endpoint[num_interrupt_out] = endpoint;
++num_interrupt_out;
}
}
#if defined(CONFIG_USB_SERIAL_PL2303) || defined(CONFIG_USB_SERIAL_PL2303_MODULE)
/* BEGIN HORRIBLE HACK FOR PL2303 */
/* this is needed due to the looney way its endpoints are set up */
if (((le16_to_cpu(dev->descriptor.idVendor) == PL2303_VENDOR_ID) &&
(le16_to_cpu(dev->descriptor.idProduct) == PL2303_PRODUCT_ID)) ||
((le16_to_cpu(dev->descriptor.idVendor) == ATEN_VENDOR_ID) &&
(le16_to_cpu(dev->descriptor.idProduct) == ATEN_PRODUCT_ID)) ||
((le16_to_cpu(dev->descriptor.idVendor) == ALCOR_VENDOR_ID) &&
(le16_to_cpu(dev->descriptor.idProduct) == ALCOR_PRODUCT_ID)) ||
((le16_to_cpu(dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
(le16_to_cpu(dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_EF81))) {
if (interface != dev->actconfig->interface[0]) {
/* check out the endpoints of the other interface*/
iface_desc = dev->actconfig->interface[0]->cur_altsetting;
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
endpoint = &iface_desc->endpoint[i].desc;
if (usb_endpoint_is_int_in(endpoint)) {
/* we found a interrupt in endpoint */
dbg("found interrupt in for Prolific device on separate interface");
interrupt_in_endpoint[num_interrupt_in] = endpoint;
++num_interrupt_in;
}
}
}
/* Now make sure the PL-2303 is configured correctly.
* If not, give up now and hope this hack will work
* properly during a later invocation of usb_serial_probe
*/
if (num_bulk_in == 0 || num_bulk_out == 0) {
dev_info(&interface->dev, "PL-2303 hack: descriptors matched but endpoints did not\n");
kfree(serial);
module_put(type->driver.owner);
return -ENODEV;
}
}
/* END HORRIBLE HACK FOR PL2303 */
#endif
#ifdef CONFIG_USB_SERIAL_GENERIC
if (type == &usb_serial_generic_device) {
num_ports = num_bulk_out;
if (num_ports == 0) {
dev_err(&interface->dev,
"Generic device with no bulk out, not allowed.\n");
kfree(serial);
module_put(type->driver.owner);
return -EIO;
}
}
#endif
if (!num_ports) {
/* if this device type has a calc_num_ports function, call it */
if (type->calc_num_ports)
num_ports = type->calc_num_ports(serial);
if (!num_ports)
num_ports = type->num_ports;
}
serial->num_ports = num_ports;
serial->num_bulk_in = num_bulk_in;
serial->num_bulk_out = num_bulk_out;
serial->num_interrupt_in = num_interrupt_in;
serial->num_interrupt_out = num_interrupt_out;
/* found all that we need */
dev_info(&interface->dev, "%s converter detected\n",
type->description);
/* create our ports, we need as many as the max endpoints */
/* we don't use num_ports here because some devices have more
endpoint pairs than ports */
max_endpoints = max(num_bulk_in, num_bulk_out);
max_endpoints = max(max_endpoints, num_interrupt_in);
max_endpoints = max(max_endpoints, num_interrupt_out);
max_endpoints = max(max_endpoints, (int)serial->num_ports);
serial->num_port_pointers = max_endpoints;
dbg("%s - setting up %d port structures for this device",
__func__, max_endpoints);
for (i = 0; i < max_endpoints; ++i) {
port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
if (!port)
goto probe_error;
tty_port_init(&port->port);
port->port.ops = &serial_port_ops;
port->serial = serial;
spin_lock_init(&port->lock);
/* Keep this for private driver use for the moment but
should probably go away */
INIT_WORK(&port->work, usb_serial_port_work);
serial->port[i] = port;
port->dev.parent = &interface->dev;
port->dev.driver = NULL;
port->dev.bus = &usb_serial_bus_type;
port->dev.release = &port_release;
device_initialize(&port->dev);
}
/* set up the endpoint information */
for (i = 0; i < num_bulk_in; ++i) {
endpoint = bulk_in_endpoint[i];
port = serial->port[i];
port->read_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!port->read_urb) {
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
buffer_size = max_t(int, serial->type->bulk_in_size,
USB: use usb_endpoint_maxp() instead of le16_to_cpu() Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size instead of le16_to_cpu(desc->wMaxPacketSize). This patch fix it up Cc: Armin Fuerst <fuerst@in.tum.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Johannes Erdfelt <johannes@erdfelt.com> Cc: Vojtech Pavlik <vojtech@suse.cz> Cc: Oliver Neukum <oliver@neukum.name> Cc: David Kubicek <dave@awk.cz> Cc: Johan Hovold <jhovold@gmail.com> Cc: Brad Hards <bhards@bigpond.net.au> Acked-by: Felipe Balbi <balbi@ti.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de> Cc: David Brownell <david-b@pacbell.net> Cc: David Lopo <dlopo@chipidea.mips.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Michal Nazarewicz <m.nazarewicz@samsung.com> Cc: Xie Xiaobo <X.Xie@freescale.com> Cc: Li Yang <leoli@freescale.com> Cc: Jiang Bo <tanya.jiang@freescale.com> Cc: Yuan-hsin Chen <yhchen@faraday-tech.com> Cc: Darius Augulis <augulis.darius@gmail.com> Cc: Xiaochen Shen <xiaochen.shen@intel.com> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Ben Dooks <ben@simtec.co.uk> Cc: Thomas Abraham <thomas.ab@samsung.com> Cc: Herbert Pötzl <herbert@13thfloor.at> Cc: Arnaud Patard <arnaud.patard@rtp-net.org> Cc: Roman Weissgaerber <weissg@vienna.at> Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Tony Olech <tony.olech@elandigitalsystems.com> Cc: Florian Floe Echtler <echtler@fs.tum.de> Cc: Christian Lucht <lucht@codemercs.com> Cc: Juergen Stuber <starblue@sourceforge.net> Cc: Georges Toth <g.toth@e-biz.lu> Cc: Bill Ryder <bryder@sgi.com> Cc: Kuba Ober <kuba@mareimbrium.org> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23 12:12:03 +02:00
usb_endpoint_maxp(endpoint));
port->bulk_in_size = buffer_size;
port->bulk_in_endpointAddress = endpoint->bEndpointAddress;
port->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
if (!port->bulk_in_buffer) {
dev_err(&interface->dev,
"Couldn't allocate bulk_in_buffer\n");
goto probe_error;
}
usb_fill_bulk_urb(port->read_urb, dev,
usb_rcvbulkpipe(dev,
endpoint->bEndpointAddress),
port->bulk_in_buffer, buffer_size,
serial->type->read_bulk_callback, port);
}
for (i = 0; i < num_bulk_out; ++i) {
int j;
endpoint = bulk_out_endpoint[i];
port = serial->port[i];
port->write_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!port->write_urb) {
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))
goto probe_error;
buffer_size = serial->type->bulk_out_size;
if (!buffer_size)
USB: use usb_endpoint_maxp() instead of le16_to_cpu() Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size instead of le16_to_cpu(desc->wMaxPacketSize). This patch fix it up Cc: Armin Fuerst <fuerst@in.tum.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Johannes Erdfelt <johannes@erdfelt.com> Cc: Vojtech Pavlik <vojtech@suse.cz> Cc: Oliver Neukum <oliver@neukum.name> Cc: David Kubicek <dave@awk.cz> Cc: Johan Hovold <jhovold@gmail.com> Cc: Brad Hards <bhards@bigpond.net.au> Acked-by: Felipe Balbi <balbi@ti.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de> Cc: David Brownell <david-b@pacbell.net> Cc: David Lopo <dlopo@chipidea.mips.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Michal Nazarewicz <m.nazarewicz@samsung.com> Cc: Xie Xiaobo <X.Xie@freescale.com> Cc: Li Yang <leoli@freescale.com> Cc: Jiang Bo <tanya.jiang@freescale.com> Cc: Yuan-hsin Chen <yhchen@faraday-tech.com> Cc: Darius Augulis <augulis.darius@gmail.com> Cc: Xiaochen Shen <xiaochen.shen@intel.com> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Ben Dooks <ben@simtec.co.uk> Cc: Thomas Abraham <thomas.ab@samsung.com> Cc: Herbert Pötzl <herbert@13thfloor.at> Cc: Arnaud Patard <arnaud.patard@rtp-net.org> Cc: Roman Weissgaerber <weissg@vienna.at> Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Tony Olech <tony.olech@elandigitalsystems.com> Cc: Florian Floe Echtler <echtler@fs.tum.de> Cc: Christian Lucht <lucht@codemercs.com> Cc: Juergen Stuber <starblue@sourceforge.net> Cc: Georges Toth <g.toth@e-biz.lu> Cc: Bill Ryder <bryder@sgi.com> Cc: Kuba Ober <kuba@mareimbrium.org> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23 12:12:03 +02:00
buffer_size = usb_endpoint_maxp(endpoint);
port->bulk_out_size = buffer_size;
port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
port->bulk_out_buffer = kmalloc(buffer_size, GFP_KERNEL);
if (!port->bulk_out_buffer) {
dev_err(&interface->dev,
"Couldn't allocate bulk_out_buffer\n");
goto probe_error;
}
usb_fill_bulk_urb(port->write_urb, dev,
usb_sndbulkpipe(dev,
endpoint->bEndpointAddress),
port->bulk_out_buffer, buffer_size,
serial->type->write_bulk_callback, port);
for (j = 0; j < ARRAY_SIZE(port->write_urbs); ++j) {
set_bit(j, &port->write_urbs_free);
port->write_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);
if (!port->write_urbs[j]) {
dev_err(&interface->dev,
"No free urbs available\n");
goto probe_error;
}
port->bulk_out_buffers[j] = kmalloc(buffer_size,
GFP_KERNEL);
if (!port->bulk_out_buffers[j]) {
dev_err(&interface->dev,
"Couldn't allocate bulk_out_buffer\n");
goto probe_error;
}
usb_fill_bulk_urb(port->write_urbs[j], dev,
usb_sndbulkpipe(dev,
endpoint->bEndpointAddress),
port->bulk_out_buffers[j], buffer_size,
serial->type->write_bulk_callback,
port);
}
}
if (serial->type->read_int_callback) {
for (i = 0; i < num_interrupt_in; ++i) {
endpoint = interrupt_in_endpoint[i];
port = serial->port[i];
port->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!port->interrupt_in_urb) {
dev_err(&interface->dev,
"No free urbs available\n");
goto probe_error;
}
USB: use usb_endpoint_maxp() instead of le16_to_cpu() Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size instead of le16_to_cpu(desc->wMaxPacketSize). This patch fix it up Cc: Armin Fuerst <fuerst@in.tum.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Johannes Erdfelt <johannes@erdfelt.com> Cc: Vojtech Pavlik <vojtech@suse.cz> Cc: Oliver Neukum <oliver@neukum.name> Cc: David Kubicek <dave@awk.cz> Cc: Johan Hovold <jhovold@gmail.com> Cc: Brad Hards <bhards@bigpond.net.au> Acked-by: Felipe Balbi <balbi@ti.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de> Cc: David Brownell <david-b@pacbell.net> Cc: David Lopo <dlopo@chipidea.mips.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Michal Nazarewicz <m.nazarewicz@samsung.com> Cc: Xie Xiaobo <X.Xie@freescale.com> Cc: Li Yang <leoli@freescale.com> Cc: Jiang Bo <tanya.jiang@freescale.com> Cc: Yuan-hsin Chen <yhchen@faraday-tech.com> Cc: Darius Augulis <augulis.darius@gmail.com> Cc: Xiaochen Shen <xiaochen.shen@intel.com> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Ben Dooks <ben@simtec.co.uk> Cc: Thomas Abraham <thomas.ab@samsung.com> Cc: Herbert Pötzl <herbert@13thfloor.at> Cc: Arnaud Patard <arnaud.patard@rtp-net.org> Cc: Roman Weissgaerber <weissg@vienna.at> Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Tony Olech <tony.olech@elandigitalsystems.com> Cc: Florian Floe Echtler <echtler@fs.tum.de> Cc: Christian Lucht <lucht@codemercs.com> Cc: Juergen Stuber <starblue@sourceforge.net> Cc: Georges Toth <g.toth@e-biz.lu> Cc: Bill Ryder <bryder@sgi.com> Cc: Kuba Ober <kuba@mareimbrium.org> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23 12:12:03 +02:00
buffer_size = usb_endpoint_maxp(endpoint);
port->interrupt_in_endpointAddress =
endpoint->bEndpointAddress;
port->interrupt_in_buffer = kmalloc(buffer_size,
GFP_KERNEL);
if (!port->interrupt_in_buffer) {
dev_err(&interface->dev,
"Couldn't allocate interrupt_in_buffer\n");
goto probe_error;
}
usb_fill_int_urb(port->interrupt_in_urb, dev,
usb_rcvintpipe(dev,
endpoint->bEndpointAddress),
port->interrupt_in_buffer, buffer_size,
serial->type->read_int_callback, port,
endpoint->bInterval);
}
} else if (num_interrupt_in) {
dbg("the device claims to support interrupt in transfers, but read_int_callback is not defined");
}
if (serial->type->write_int_callback) {
for (i = 0; i < num_interrupt_out; ++i) {
endpoint = interrupt_out_endpoint[i];
port = serial->port[i];
port->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!port->interrupt_out_urb) {
dev_err(&interface->dev,
"No free urbs available\n");
goto probe_error;
}
USB: use usb_endpoint_maxp() instead of le16_to_cpu() Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size instead of le16_to_cpu(desc->wMaxPacketSize). This patch fix it up Cc: Armin Fuerst <fuerst@in.tum.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Johannes Erdfelt <johannes@erdfelt.com> Cc: Vojtech Pavlik <vojtech@suse.cz> Cc: Oliver Neukum <oliver@neukum.name> Cc: David Kubicek <dave@awk.cz> Cc: Johan Hovold <jhovold@gmail.com> Cc: Brad Hards <bhards@bigpond.net.au> Acked-by: Felipe Balbi <balbi@ti.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de> Cc: David Brownell <david-b@pacbell.net> Cc: David Lopo <dlopo@chipidea.mips.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Michal Nazarewicz <m.nazarewicz@samsung.com> Cc: Xie Xiaobo <X.Xie@freescale.com> Cc: Li Yang <leoli@freescale.com> Cc: Jiang Bo <tanya.jiang@freescale.com> Cc: Yuan-hsin Chen <yhchen@faraday-tech.com> Cc: Darius Augulis <augulis.darius@gmail.com> Cc: Xiaochen Shen <xiaochen.shen@intel.com> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Ben Dooks <ben@simtec.co.uk> Cc: Thomas Abraham <thomas.ab@samsung.com> Cc: Herbert Pötzl <herbert@13thfloor.at> Cc: Arnaud Patard <arnaud.patard@rtp-net.org> Cc: Roman Weissgaerber <weissg@vienna.at> Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Tony Olech <tony.olech@elandigitalsystems.com> Cc: Florian Floe Echtler <echtler@fs.tum.de> Cc: Christian Lucht <lucht@codemercs.com> Cc: Juergen Stuber <starblue@sourceforge.net> Cc: Georges Toth <g.toth@e-biz.lu> Cc: Bill Ryder <bryder@sgi.com> Cc: Kuba Ober <kuba@mareimbrium.org> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23 12:12:03 +02:00
buffer_size = usb_endpoint_maxp(endpoint);
port->interrupt_out_size = buffer_size;
port->interrupt_out_endpointAddress =
endpoint->bEndpointAddress;
port->interrupt_out_buffer = kmalloc(buffer_size,
GFP_KERNEL);
if (!port->interrupt_out_buffer) {
dev_err(&interface->dev,
"Couldn't allocate interrupt_out_buffer\n");
goto probe_error;
}
usb_fill_int_urb(port->interrupt_out_urb, dev,
usb_sndintpipe(dev,
endpoint->bEndpointAddress),
port->interrupt_out_buffer, buffer_size,
serial->type->write_int_callback, port,
endpoint->bInterval);
}
} else if (num_interrupt_out) {
dbg("the device claims to support interrupt out transfers, but write_int_callback is not defined");
}
/* if this device type has an attach function, call it */
if (type->attach) {
retval = type->attach(serial);
if (retval < 0)
goto probe_error;
serial->attached = 1;
if (retval > 0) {
/* quietly accept this device, but don't bind to a
serial port as it's about to disappear */
serial->num_ports = 0;
goto exit;
}
} else {
serial->attached = 1;
}
if (get_free_serial(serial, num_ports, &minor) == NULL) {
dev_err(&interface->dev, "No more free serial devices\n");
goto probe_error;
}
serial->minor = minor;
/* register all of the individual ports with the driver core */
for (i = 0; i < num_ports; ++i) {
port = serial->port[i];
dev_set_name(&port->dev, "ttyUSB%d", port->number);
dbg ("%s - registering %s", __func__, dev_name(&port->dev));
port->dev_state = PORT_REGISTERING;
device_enable_async_suspend(&port->dev);
retval = device_add(&port->dev);
if (retval) {
dev_err(&port->dev, "Error registering port device, "
"continuing\n");
port->dev_state = PORT_UNREGISTERED;
} else {
port->dev_state = PORT_REGISTERED;
}
}
usb_serial_console_init(debug, minor);
exit:
/* success */
usb_set_intfdata(interface, serial);
module_put(type->driver.owner);
return 0;
probe_error:
usb_serial_put(serial);
module_put(type->driver.owner);
return -EIO;
}
EXPORT_SYMBOL_GPL(usb_serial_probe);
void usb_serial_disconnect(struct usb_interface *interface)
{
int i;
struct usb_serial *serial = usb_get_intfdata(interface);
struct device *dev = &interface->dev;
struct usb_serial_port *port;
usb_serial_console_disconnect(serial);
dbg("%s", __func__);
mutex_lock(&serial->disc_mutex);
usb_set_intfdata(interface, NULL);
/* must set a flag, to signal subdrivers */
serial->disconnected = 1;
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
mutex_unlock(&serial->disc_mutex);
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
if (port) {
struct tty_struct *tty = tty_port_tty_get(&port->port);
if (tty) {
tty_vhangup(tty);
tty_kref_put(tty);
}
kill_traffic(port);
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
cancel_work_sync(&port->work);
if (port->dev_state == PORT_REGISTERED) {
/* Make sure the port is bound so that the
* driver's port_remove method is called.
*/
if (!port->dev.driver) {
int rc;
port->dev.driver =
&serial->type->driver;
rc = device_bind_driver(&port->dev);
}
port->dev_state = PORT_UNREGISTERING;
device_del(&port->dev);
port->dev_state = PORT_UNREGISTERED;
}
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
}
}
serial->type->disconnect(serial);
USB: serial: fix lifetime and locking problems This patch (as1229) fixes a few lifetime and locking problems in the usb-serial driver. The main symptom is that an invalid kevent is created when the serial device is unplugged while a connection is active. Ports should be unregistered when device is disconnected, not when the parent usb_serial structure is deallocated. Each open file should hold a reference to the corresponding port structure, and the reference should be released when the file is closed. serial->disc_mutex should be acquired in serial_open(), to resolve the classic race between open and disconnect. serial_close() doesn't need to hold both serial->disc_mutex and port->mutex at the same time. Release the subdriver's module reference only after releasing all the other references, in case one of the release routines needs to invoke some code in the subdriver module. Replace a call to flush_scheduled_work() (which is prone to deadlocks) with cancel_work_sync(). Also, add a call to cancel_work_sync() in the disconnect routine. Reduce the scope of serial->disc_mutex in serial_disconnect(). The only place it really needs to protect is where the "disconnected" flag is set. This fixes the bug reported in http://bugs.freedesktop.org/show_bug.cgi?id=20703 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Dan Williams <dcbw@redhat.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Oliver Neukum <oliver@neukum.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-14 17:31:02 +02:00
/* let the last holder of this object cause it to be cleaned up */
usb_serial_put(serial);
dev_info(dev, "device disconnected\n");
}
EXPORT_SYMBOL_GPL(usb_serial_disconnect);
int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
{
struct usb_serial *serial = usb_get_intfdata(intf);
struct usb_serial_port *port;
int i, r = 0;
serial->suspending = 1;
if (serial->type->suspend) {
r = serial->type->suspend(serial, message);
if (r < 0) {
serial->suspending = 0;
goto err_out;
}
}
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
if (port)
kill_traffic(port);
}
err_out:
return r;
}
EXPORT_SYMBOL(usb_serial_suspend);
int usb_serial_resume(struct usb_interface *intf)
{
struct usb_serial *serial = usb_get_intfdata(intf);
int rv;
serial->suspending = 0;
if (serial->type->resume)
rv = serial->type->resume(serial);
else
rv = usb_serial_generic_resume(serial);
return rv;
}
EXPORT_SYMBOL(usb_serial_resume);
static const struct tty_operations serial_ops = {
.open = serial_open,
.close = serial_close,
.write = serial_write,
.hangup = serial_hangup,
.write_room = serial_write_room,
.ioctl = serial_ioctl,
.set_termios = serial_set_termios,
.throttle = serial_throttle,
.unthrottle = serial_unthrottle,
.break_ctl = serial_break,
.chars_in_buffer = serial_chars_in_buffer,
.tiocmget = serial_tiocmget,
.tiocmset = serial_tiocmset,
.get_icount = serial_get_icount,
tty: Fix regressions caused by commit b50989dc The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox <alan@linux.intel.com> Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young <hidave.darkstar@gmail.com> [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 18:00:42 +02:00
.cleanup = serial_cleanup,
.install = serial_install,
.proc_fops = &serial_proc_fops,
};
struct tty_driver *usb_serial_tty_driver;
static int __init usb_serial_init(void)
{
int i;
int result;
usb_serial_tty_driver = alloc_tty_driver(SERIAL_TTY_MINORS);
if (!usb_serial_tty_driver)
return -ENOMEM;
/* Initialize our global data */
for (i = 0; i < SERIAL_TTY_MINORS; ++i)
serial_table[i] = NULL;
result = bus_register(&usb_serial_bus_type);
if (result) {
printk(KERN_ERR "usb-serial: %s - registering bus driver "
"failed\n", __func__);
goto exit_bus;
}
usb_serial_tty_driver->owner = THIS_MODULE;
usb_serial_tty_driver->driver_name = "usbserial";
usb_serial_tty_driver->name = "ttyUSB";
usb_serial_tty_driver->major = SERIAL_TTY_MAJOR;
usb_serial_tty_driver->minor_start = 0;
usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;
usb_serial_tty_driver->flags = TTY_DRIVER_REAL_RAW |
TTY_DRIVER_DYNAMIC_DEV;
usb_serial_tty_driver->init_termios = tty_std_termios;
usb_serial_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD
| HUPCL | CLOCAL;
usb_serial_tty_driver->init_termios.c_ispeed = 9600;
usb_serial_tty_driver->init_termios.c_ospeed = 9600;
tty_set_operations(usb_serial_tty_driver, &serial_ops);
result = tty_register_driver(usb_serial_tty_driver);
if (result) {
printk(KERN_ERR "usb-serial: %s - tty_register_driver failed\n",
__func__);
goto exit_reg_driver;
}
/* register the USB driver */
result = usb_register(&usb_serial_driver);
if (result < 0) {
printk(KERN_ERR "usb-serial: %s - usb_register failed\n",
__func__);
goto exit_tty;
}
/* register the generic driver, if we should */
result = usb_serial_generic_register(debug);
if (result < 0) {
printk(KERN_ERR "usb-serial: %s - registering generic "
"driver failed\n", __func__);
goto exit_generic;
}
printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
return result;
exit_generic:
usb_deregister(&usb_serial_driver);
exit_tty:
tty_unregister_driver(usb_serial_tty_driver);
exit_reg_driver:
bus_unregister(&usb_serial_bus_type);
exit_bus:
printk(KERN_ERR "usb-serial: %s - returning with error %d\n",
__func__, result);
put_tty_driver(usb_serial_tty_driver);
return result;
}
static void __exit usb_serial_exit(void)
{
usb_serial_console_exit();
usb_serial_generic_deregister();
usb_deregister(&usb_serial_driver);
tty_unregister_driver(usb_serial_tty_driver);
put_tty_driver(usb_serial_tty_driver);
bus_unregister(&usb_serial_bus_type);
}
module_init(usb_serial_init);
module_exit(usb_serial_exit);
#define set_to_generic_if_null(type, function) \
do { \
if (!type->function) { \
type->function = usb_serial_generic_##function; \
dbg("Had to override the " #function \
" usb serial operation with the generic one.");\
} \
} while (0)
static void fixup_generic(struct usb_serial_driver *device)
{
set_to_generic_if_null(device, open);
set_to_generic_if_null(device, write);
set_to_generic_if_null(device, close);
set_to_generic_if_null(device, write_room);
set_to_generic_if_null(device, chars_in_buffer);
set_to_generic_if_null(device, read_bulk_callback);
set_to_generic_if_null(device, write_bulk_callback);
set_to_generic_if_null(device, disconnect);
set_to_generic_if_null(device, release);
set_to_generic_if_null(device, process_read_urb);
set_to_generic_if_null(device, prepare_write_buffer);
}
int usb_serial_register(struct usb_serial_driver *driver)
{
/* must be called with BKL held */
int retval;
if (usb_disabled())
return -ENODEV;
fixup_generic(driver);
if (!driver->description)
driver->description = driver->driver.name;
if (!driver->usb_driver) {
WARN(1, "Serial driver %s has no usb_driver\n",
driver->description);
return -EINVAL;
}
driver->usb_driver->supports_autosuspend = 1;
/* Add this device to our list of devices */
mutex_lock(&table_lock);
list_add(&driver->driver_list, &usb_serial_driver_list);
retval = usb_serial_bus_register(driver);
if (retval) {
printk(KERN_ERR "usb-serial: problem %d when registering "
"driver %s\n", retval, driver->description);
list_del(&driver->driver_list);
} else
printk(KERN_INFO "USB Serial support registered for %s\n",
driver->description);
mutex_unlock(&table_lock);
return retval;
}
EXPORT_SYMBOL_GPL(usb_serial_register);
void usb_serial_deregister(struct usb_serial_driver *device)
{
/* must be called with BKL held */
printk(KERN_INFO "USB Serial deregistering driver %s\n",
device->description);
mutex_lock(&table_lock);
list_del(&device->driver_list);
usb_serial_bus_deregister(device);
mutex_unlock(&table_lock);
}
EXPORT_SYMBOL_GPL(usb_serial_deregister);
/* Module information */
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");