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USB: rio500: simplify locking 

Admitting that there can be only one device allows us to drop any
pretense about locking one device or a table of devices.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Oliver Neukum 2019-05-09 11:31:00 +02:00 committed by Greg Kroah-Hartman
parent e0feb73428
commit d710734b06
1 changed files with 16 additions and 27 deletions
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43
drivers/usb/misc/rio500.c
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@ -51,7 +51,6 @@ struct rio_usb_data {
char *obuf, *ibuf; /* transfer buffers */ char *obuf, *ibuf; /* transfer buffers */
char bulk_in_ep, bulk_out_ep; /* Endpoint assignments */ char bulk_in_ep, bulk_out_ep; /* Endpoint assignments */
wait_queue_head_t wait_q; /* for timeouts */ wait_queue_head_t wait_q; /* for timeouts */
struct mutex lock; /* general race avoidance */
}; };
static DEFINE_MUTEX(rio500_mutex); static DEFINE_MUTEX(rio500_mutex);
@ -63,10 +62,8 @@ static int open_rio(struct inode *inode, struct file *file)
/* against disconnect() */ /* against disconnect() */
mutex_lock(&rio500_mutex); mutex_lock(&rio500_mutex);
mutex_lock(&(rio->lock));
if (rio->isopen || !rio->present) { if (rio->isopen || !rio->present) {
mutex_unlock(&(rio->lock));
mutex_unlock(&rio500_mutex); mutex_unlock(&rio500_mutex);
return -EBUSY; return -EBUSY;
} }
@ -74,7 +71,6 @@ static int open_rio(struct inode *inode, struct file *file)
init_waitqueue_head(&rio->wait_q); init_waitqueue_head(&rio->wait_q);
mutex_unlock(&(rio->lock));
dev_info(&rio->rio_dev->dev, "Rio opened.\n"); dev_info(&rio->rio_dev->dev, "Rio opened.\n");
mutex_unlock(&rio500_mutex); mutex_unlock(&rio500_mutex);
@ -88,7 +84,6 @@ static int close_rio(struct inode *inode, struct file *file)
/* against disconnect() */ /* against disconnect() */
mutex_lock(&rio500_mutex); mutex_lock(&rio500_mutex);
mutex_lock(&(rio->lock));
rio->isopen = 0; rio->isopen = 0;
if (!rio->present) { if (!rio->present) {
@ -100,7 +95,6 @@ static int close_rio(struct inode *inode, struct file *file)
} else { } else {
dev_info(&rio->rio_dev->dev, "Rio closed.\n"); dev_info(&rio->rio_dev->dev, "Rio closed.\n");
} }
mutex_unlock(&(rio->lock));
mutex_unlock(&rio500_mutex); mutex_unlock(&rio500_mutex);
return 0; return 0;
} }
@ -115,7 +109,7 @@ static long ioctl_rio(struct file *file, unsigned int cmd, unsigned long arg)
int retries; int retries;
int retval=0; int retval=0;
mutex_lock(&(rio->lock)); mutex_lock(&rio500_mutex);
/* Sanity check to make sure rio is connected, powered, etc */ /* Sanity check to make sure rio is connected, powered, etc */
if (rio->present == 0 || rio->rio_dev == NULL) { if (rio->present == 0 || rio->rio_dev == NULL) {
retval = -ENODEV; retval = -ENODEV;
@ -259,7 +253,7 @@ static long ioctl_rio(struct file *file, unsigned int cmd, unsigned long arg)
err_out: err_out:
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return retval; return retval;
} }
@ -279,12 +273,12 @@ write_rio(struct file *file, const char __user *buffer,
int errn = 0; int errn = 0;
int intr; int intr;
intr = mutex_lock_interruptible(&(rio->lock)); intr = mutex_lock_interruptible(&rio500_mutex);
if (intr) if (intr)
return -EINTR; return -EINTR;
/* Sanity check to make sure rio is connected, powered, etc */ /* Sanity check to make sure rio is connected, powered, etc */
if (rio->present == 0 || rio->rio_dev == NULL) { if (rio->present == 0 || rio->rio_dev == NULL) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return -ENODEV; return -ENODEV;
} }
@ -307,7 +301,7 @@ write_rio(struct file *file, const char __user *buffer,
goto error; goto error;
} }
if (signal_pending(current)) { if (signal_pending(current)) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return bytes_written ? bytes_written : -EINTR; return bytes_written ? bytes_written : -EINTR;
} }
@ -345,12 +339,12 @@ write_rio(struct file *file, const char __user *buffer,
buffer += copy_size; buffer += copy_size;
} while (count > 0); } while (count > 0);
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return bytes_written ? bytes_written : -EIO; return bytes_written ? bytes_written : -EIO;
error: error:
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return errn; return errn;
} }
@ -367,12 +361,12 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
char *ibuf; char *ibuf;
int intr; int intr;
intr = mutex_lock_interruptible(&(rio->lock)); intr = mutex_lock_interruptible(&rio500_mutex);
if (intr) if (intr)
return -EINTR; return -EINTR;
/* Sanity check to make sure rio is connected, powered, etc */ /* Sanity check to make sure rio is connected, powered, etc */
if (rio->present == 0 || rio->rio_dev == NULL) { if (rio->present == 0 || rio->rio_dev == NULL) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return -ENODEV; return -ENODEV;
} }
@ -383,11 +377,11 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
while (count > 0) { while (count > 0) {
if (signal_pending(current)) { if (signal_pending(current)) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return read_count ? read_count : -EINTR; return read_count ? read_count : -EINTR;
} }
if (!rio->rio_dev) { if (!rio->rio_dev) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return -ENODEV; return -ENODEV;
} }
this_read = (count >= IBUF_SIZE) ? IBUF_SIZE : count; this_read = (count >= IBUF_SIZE) ? IBUF_SIZE : count;
@ -405,7 +399,7 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
count = this_read = partial; count = this_read = partial;
} else if (result == -ETIMEDOUT || result == 15) { /* FIXME: 15 ??? */ } else if (result == -ETIMEDOUT || result == 15) { /* FIXME: 15 ??? */
if (!maxretry--) { if (!maxretry--) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
dev_err(&rio->rio_dev->dev, dev_err(&rio->rio_dev->dev,
"read_rio: maxretry timeout\n"); "read_rio: maxretry timeout\n");
return -ETIME; return -ETIME;
@ -415,19 +409,19 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
finish_wait(&rio->wait_q, &wait); finish_wait(&rio->wait_q, &wait);
continue; continue;
} else if (result != -EREMOTEIO) { } else if (result != -EREMOTEIO) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
dev_err(&rio->rio_dev->dev, dev_err(&rio->rio_dev->dev,
"Read Whoops - result:%d partial:%u this_read:%u\n", "Read Whoops - result:%d partial:%u this_read:%u\n",
result, partial, this_read); result, partial, this_read);
return -EIO; return -EIO;
} else { } else {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return (0); return (0);
} }
if (this_read) { if (this_read) {
if (copy_to_user(buffer, ibuf, this_read)) { if (copy_to_user(buffer, ibuf, this_read)) {
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return -EFAULT; return -EFAULT;
} }
count -= this_read; count -= this_read;
@ -435,7 +429,7 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
buffer += this_read; buffer += this_read;
} }
} }
mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex);
return read_count; return read_count;
} }
@ -500,8 +494,6 @@ static int probe_rio(struct usb_interface *intf,
} }
dev_dbg(&intf->dev, "ibuf address:%p\n", rio->ibuf); dev_dbg(&intf->dev, "ibuf address:%p\n", rio->ibuf);
mutex_init(&(rio->lock));
usb_set_intfdata (intf, rio); usb_set_intfdata (intf, rio);
rio->present = 1; rio->present = 1;
bail_out: bail_out:
@ -519,12 +511,10 @@ static void disconnect_rio(struct usb_interface *intf)
if (rio) { if (rio) {
usb_deregister_dev(intf, &usb_rio_class); usb_deregister_dev(intf, &usb_rio_class);
mutex_lock(&(rio->lock));
if (rio->isopen) { if (rio->isopen) {
rio->isopen = 0; rio->isopen = 0;
/* better let it finish - the release will do whats needed */ /* better let it finish - the release will do whats needed */
rio->rio_dev = NULL; rio->rio_dev = NULL;
mutex_unlock(&(rio->lock));
mutex_unlock(&rio500_mutex); mutex_unlock(&rio500_mutex);
return; return;
} }
@ -534,7 +524,6 @@ static void disconnect_rio(struct usb_interface *intf)
dev_info(&intf->dev, "USB Rio disconnected.\n"); dev_info(&intf->dev, "USB Rio disconnected.\n");
rio->present = 0; rio->present = 0;
mutex_unlock(&(rio->lock));
} }
mutex_unlock(&rio500_mutex); mutex_unlock(&rio500_mutex);
} }