diff options
| -rw-r--r-- | drivers/usb/class/cdc-wdm.c | 49 |
1 files changed, 31 insertions, 18 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index bac7478f517..bdfa96d6005 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -88,7 +88,8 @@ struct wdm_device { int count; dma_addr_t shandle; dma_addr_t ihandle; - struct mutex lock; + struct mutex wlock; + struct mutex rlock; wait_queue_head_t wait; struct work_struct rxwork; int werr; @@ -323,7 +324,7 @@ static ssize_t wdm_write } /* concurrent writes and disconnect */ - r = mutex_lock_interruptible(&desc->lock); + r = mutex_lock_interruptible(&desc->wlock); rv = -ERESTARTSYS; if (r) { kfree(buf); @@ -386,7 +387,7 @@ static ssize_t wdm_write out: usb_autopm_put_interface(desc->intf); outnp: - mutex_unlock(&desc->lock); + mutex_unlock(&desc->wlock); outnl: return rv < 0 ? rv : count; } @@ -399,7 +400,7 @@ static ssize_t wdm_read struct wdm_device *desc = file->private_data; - rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */ + rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ if (rv < 0) return -ERESTARTSYS; @@ -476,7 +477,7 @@ retry: rv = cntr; err: - mutex_unlock(&desc->lock); + mutex_unlock(&desc->rlock); return rv; } @@ -542,7 +543,8 @@ static int wdm_open(struct inode *inode, struct file *file) } intf->needs_remote_wakeup = 1; - mutex_lock(&desc->lock); + /* using write lock to protect desc->count */ + mutex_lock(&desc->wlock); if (!desc->count++) { desc->werr = 0; desc->rerr = 0; @@ -555,7 +557,7 @@ static int wdm_open(struct inode *inode, struct file *file) } else { rv = 0; } - mutex_unlock(&desc->lock); + mutex_unlock(&desc->wlock); usb_autopm_put_interface(desc->intf); out: mutex_unlock(&wdm_mutex); @@ -567,9 +569,11 @@ static int wdm_release(struct inode *inode, struct file *file) struct wdm_device *desc = file->private_data; mutex_lock(&wdm_mutex); - mutex_lock(&desc->lock); + + /* using write lock to protect desc->count */ + mutex_lock(&desc->wlock); desc->count--; - mutex_unlock(&desc->lock); + mutex_unlock(&desc->wlock); if (!desc->count) { dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); @@ -667,7 +671,8 @@ next_desc: desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); if (!desc) goto out; - mutex_init(&desc->lock); + mutex_init(&desc->rlock); + mutex_init(&desc->wlock); spin_lock_init(&desc->iuspin); init_waitqueue_head(&desc->wait); desc->wMaxCommand = maxcom; @@ -781,10 +786,12 @@ static void wdm_disconnect(struct usb_interface *intf) /* to terminate pending flushes */ clear_bit(WDM_IN_USE, &desc->flags); spin_unlock_irqrestore(&desc->iuspin, flags); - mutex_lock(&desc->lock); + mutex_lock(&desc->rlock); + mutex_lock(&desc->wlock); kill_urbs(desc); cancel_work_sync(&desc->rxwork); - mutex_unlock(&desc->lock); + mutex_unlock(&desc->wlock); + mutex_unlock(&desc->rlock); wake_up_all(&desc->wait); if (!desc->count) cleanup(desc); @@ -800,8 +807,10 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message) dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); /* if this is an autosuspend the caller does the locking */ - if (!(message.event & PM_EVENT_AUTO)) - mutex_lock(&desc->lock); + if (!(message.event & PM_EVENT_AUTO)) { + mutex_lock(&desc->rlock); + mutex_lock(&desc->wlock); + } spin_lock_irq(&desc->iuspin); if ((message.event & PM_EVENT_AUTO) && @@ -817,8 +826,10 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message) kill_urbs(desc); cancel_work_sync(&desc->rxwork); } - if (!(message.event & PM_EVENT_AUTO)) - mutex_unlock(&desc->lock); + if (!(message.event & PM_EVENT_AUTO)) { + mutex_unlock(&desc->wlock); + mutex_unlock(&desc->rlock); + } return rv; } @@ -856,7 +867,8 @@ static int wdm_pre_reset(struct usb_interface *intf) { struct wdm_device *desc = usb_get_intfdata(intf); - mutex_lock(&desc->lock); + mutex_lock(&desc->rlock); + mutex_lock(&desc->wlock); kill_urbs(desc); /* @@ -878,7 +890,8 @@ static int wdm_post_reset(struct usb_interface *intf) int rv; rv = recover_from_urb_loss(desc); - mutex_unlock(&desc->lock); + mutex_unlock(&desc->wlock); + mutex_unlock(&desc->rlock); return 0; } |