uwb: don't unbind the radio controller driver when resetting

Use pre_reset and post_reset methods to avoid unbinding the radio
controller driver after a uwb_rc_reset_all() call.  This avoids a
deadlock in uwb_rc_rm() when waiting for the uwb event thread to stop.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
This commit is contained in:
David Vrabel 2008-11-07 17:37:33 +00:00
parent fec1a5932f
commit 307ba6dd73
8 changed files with 155 additions and 42 deletions

View File

@ -881,6 +881,24 @@ static void hwarc_disconnect(struct usb_interface *iface)
uwb_rc_put(uwb_rc); /* when creating the device, refcount = 1 */
}
static int hwarc_pre_reset(struct usb_interface *iface)
{
struct hwarc *hwarc = usb_get_intfdata(iface);
struct uwb_rc *uwb_rc = hwarc->uwb_rc;
uwb_rc_pre_reset(uwb_rc);
return 0;
}
static int hwarc_post_reset(struct usb_interface *iface)
{
struct hwarc *hwarc = usb_get_intfdata(iface);
struct uwb_rc *uwb_rc = hwarc->uwb_rc;
uwb_rc_post_reset(uwb_rc);
return 0;
}
/** USB device ID's that we handle */
static struct usb_device_id hwarc_id_table[] = {
/* D-Link DUB-1210 */
@ -897,9 +915,11 @@ MODULE_DEVICE_TABLE(usb, hwarc_id_table);
static struct usb_driver hwarc_driver = {
.name = "hwa-rc",
.id_table = hwarc_id_table,
.probe = hwarc_probe,
.disconnect = hwarc_disconnect,
.id_table = hwarc_id_table,
.pre_reset = hwarc_pre_reset,
.post_reset = hwarc_post_reset,
};
static int __init hwarc_driver_init(void)

View File

@ -323,17 +323,16 @@ int uwbd_msg_handle_reset(struct uwb_event *evt)
struct uwb_rc *rc = evt->rc;
int ret;
/* Need to prevent the RC hardware module going away while in
the rc->reset() call. */
if (!try_module_get(rc->owner))
return 0;
dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
ret = rc->reset(rc);
if (ret)
if (ret) {
dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
module_put(rc->owner);
goto error;
}
return 0;
error:
/* Nothing can be done except try the reset again. */
uwb_rc_reset_all(rc);
return ret;
}
@ -360,3 +359,37 @@ void uwb_rc_reset_all(struct uwb_rc *rc)
uwbd_event_queue(evt);
}
EXPORT_SYMBOL_GPL(uwb_rc_reset_all);
void uwb_rc_pre_reset(struct uwb_rc *rc)
{
rc->stop(rc);
uwbd_flush(rc);
mutex_lock(&rc->uwb_dev.mutex);
rc->beaconing = -1;
rc->scanning = -1;
mutex_unlock(&rc->uwb_dev.mutex);
uwb_rsv_remove_all(rc);
}
EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);
void uwb_rc_post_reset(struct uwb_rc *rc)
{
int ret;
ret = rc->start(rc);
if (ret)
goto error;
ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);
if (ret)
goto error;
ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);
if (ret)
goto error;
return;
error:
/* Nothing can be done except try the reset again. */
uwb_rc_reset_all(rc);
}
EXPORT_SYMBOL_GPL(uwb_rc_post_reset);

View File

@ -659,6 +659,25 @@ static void uwb_rsv_timer(unsigned long arg)
uwb_rsv_sched_update(rsv->rc);
}
/**
* uwb_rsv_remove_all - remove all reservations
* @rc: the radio controller
*
* A DRP IE update is not done.
*/
void uwb_rsv_remove_all(struct uwb_rc *rc)
{
struct uwb_rsv *rsv, *t;
mutex_lock(&rc->rsvs_mutex);
list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
uwb_rsv_remove(rsv);
}
mutex_unlock(&rc->rsvs_mutex);
cancel_work_sync(&rc->rsv_update_work);
}
void uwb_rsv_init(struct uwb_rc *rc)
{
INIT_LIST_HEAD(&rc->reservations);
@ -682,14 +701,6 @@ int uwb_rsv_setup(struct uwb_rc *rc)
void uwb_rsv_cleanup(struct uwb_rc *rc)
{
struct uwb_rsv *rsv, *t;
mutex_lock(&rc->rsvs_mutex);
list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
uwb_rsv_remove(rsv);
}
mutex_unlock(&rc->rsvs_mutex);
cancel_work_sync(&rc->rsv_update_work);
uwb_rsv_remove_all(rc);
destroy_workqueue(rc->rsv_workq);
}

View File

@ -11,23 +11,48 @@
#include <linux/uwb/umc.h>
#include <linux/pci.h>
static int umc_bus_unbind_helper(struct device *dev, void *data)
static int umc_bus_pre_reset_helper(struct device *dev, void *data)
{
struct device *parent = data;
int ret = 0;
if (dev->parent == parent && dev->driver)
device_release_driver(dev);
return 0;
if (dev->driver) {
struct umc_dev *umc = to_umc_dev(dev);
struct umc_driver *umc_drv = to_umc_driver(dev->driver);
if (umc_drv->pre_reset)
ret = umc_drv->pre_reset(umc);
else
device_release_driver(dev);
}
return ret;
}
static int umc_bus_post_reset_helper(struct device *dev, void *data)
{
int ret = 0;
if (dev->driver) {
struct umc_dev *umc = to_umc_dev(dev);
struct umc_driver *umc_drv = to_umc_driver(dev->driver);
if (umc_drv->post_reset)
ret = umc_drv->post_reset(umc);
} else
ret = device_attach(dev);
return ret;
}
/**
* umc_controller_reset - reset the whole UMC controller
* @umc: the UMC device for the radio controller.
*
* Drivers will be unbound from all UMC devices belonging to the
* controller and then the radio controller will be rebound. The
* radio controller is expected to do a full hardware reset when it is
* probed.
* Drivers or all capabilities of the controller will have their
* pre_reset methods called or be unbound from their device. Then all
* post_reset methods will be called or the drivers will be rebound.
*
* Radio controllers must provide pre_reset and post_reset methods and
* reset the hardware in their start method.
*
* If this is called while a probe() or remove() is in progress it
* will return -EAGAIN and not perform the reset.
@ -35,14 +60,13 @@ static int umc_bus_unbind_helper(struct device *dev, void *data)
int umc_controller_reset(struct umc_dev *umc)
{
struct device *parent = umc->dev.parent;
int ret;
int ret = 0;
if (down_trylock(&parent->sem))
if(down_trylock(&parent->sem))
return -EAGAIN;
bus_for_each_dev(&umc_bus_type, NULL, parent, umc_bus_unbind_helper);
ret = device_attach(&umc->dev);
if (ret == 1)
ret = 0;
ret = device_for_each_child(parent, parent, umc_bus_pre_reset_helper);
if (ret >= 0)
device_for_each_child(parent, parent, umc_bus_post_reset_helper);
up(&parent->sem);
return ret;
@ -75,10 +99,10 @@ static int umc_bus_rescan_helper(struct device *dev, void *data)
if (!dev->driver)
ret = device_attach(dev);
return ret < 0 ? ret : 0;
return ret;
}
static void umc_bus_rescan(void)
static void umc_bus_rescan(struct device *parent)
{
int err;
@ -86,7 +110,7 @@ static void umc_bus_rescan(void)
* We can't use bus_rescan_devices() here as it deadlocks when
* it tries to retake the dev->parent semaphore.
*/
err = bus_for_each_dev(&umc_bus_type, NULL, NULL, umc_bus_rescan_helper);
err = device_for_each_child(parent, NULL, umc_bus_rescan_helper);
if (err < 0)
printk(KERN_WARNING "%s: rescan of bus failed: %d\n",
KBUILD_MODNAME, err);
@ -120,7 +144,7 @@ static int umc_device_probe(struct device *dev)
if (err)
put_device(dev);
else
umc_bus_rescan();
umc_bus_rescan(dev->parent);
return err;
}

View File

@ -248,6 +248,7 @@ extern struct device_attribute dev_attr_scan;
void uwb_rsv_init(struct uwb_rc *rc);
int uwb_rsv_setup(struct uwb_rc *rc);
void uwb_rsv_cleanup(struct uwb_rc *rc);
void uwb_rsv_remove_all(struct uwb_rc *rc);
void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state);
void uwb_rsv_remove(struct uwb_rsv *rsv);

View File

@ -394,7 +394,7 @@ void whcrc_stop_rc(struct uwb_rc *rc)
le_writel(0, whcrc->rc_base + URCCMD);
whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS,
URCSTS_HALTED, 0, 40, "URCSTS.HALTED");
URCSTS_HALTED, URCSTS_HALTED, 100, "URCSTS.HALTED");
}
static void whcrc_init(struct whcrc *whcrc)
@ -488,6 +488,24 @@ static void whcrc_remove(struct umc_dev *umc_dev)
d_printf(1, &umc_dev->dev, "freed whcrc %p\n", whcrc);
}
static int whcrc_pre_reset(struct umc_dev *umc)
{
struct whcrc *whcrc = umc_get_drvdata(umc);
struct uwb_rc *uwb_rc = whcrc->uwb_rc;
uwb_rc_pre_reset(uwb_rc);
return 0;
}
static int whcrc_post_reset(struct umc_dev *umc)
{
struct whcrc *whcrc = umc_get_drvdata(umc);
struct uwb_rc *uwb_rc = whcrc->uwb_rc;
uwb_rc_post_reset(uwb_rc);
return 0;
}
/* PCI device ID's that we handle [so it gets loaded] */
static struct pci_device_id whcrc_id_table[] = {
{ PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) },
@ -496,10 +514,12 @@ static struct pci_device_id whcrc_id_table[] = {
MODULE_DEVICE_TABLE(pci, whcrc_id_table);
static struct umc_driver whcrc_driver = {
.name = "whc-rc",
.cap_id = UMC_CAP_ID_WHCI_RC,
.probe = whcrc_probe,
.remove = whcrc_remove,
.name = "whc-rc",
.cap_id = UMC_CAP_ID_WHCI_RC,
.probe = whcrc_probe,
.remove = whcrc_remove,
.pre_reset = whcrc_pre_reset,
.post_reset = whcrc_post_reset,
};
static int __init whcrc_driver_init(void)

View File

@ -540,6 +540,8 @@ void uwb_rc_rm(struct uwb_rc *);
void uwb_rc_neh_grok(struct uwb_rc *, void *, size_t);
void uwb_rc_neh_error(struct uwb_rc *, int);
void uwb_rc_reset_all(struct uwb_rc *rc);
void uwb_rc_pre_reset(struct uwb_rc *rc);
void uwb_rc_post_reset(struct uwb_rc *rc);
/**
* uwb_rsv_is_owner - is the owner of this reservation the RC?

View File

@ -89,6 +89,8 @@ struct umc_driver {
void (*remove)(struct umc_dev *);
int (*suspend)(struct umc_dev *, pm_message_t state);
int (*resume)(struct umc_dev *);
int (*pre_reset)(struct umc_dev *);
int (*post_reset)(struct umc_dev *);
struct device_driver driver;
};