1 files changed, 79 insertions, 57 deletions

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 3e564bfe17d1..189141ca4e05 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -31,7 +31,7 @@
 #define DRIVER_AUTHOR "Oliver Neukum"
 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
 
-static struct usb_device_id wdm_ids[] = {
+static const struct usb_device_id wdm_ids[] = {
         {
                 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
                                  USB_DEVICE_ID_MATCH_INT_SUBCLASS,
@@ -52,7 +52,8 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
 #define WDM_READ                4
 #define WDM_INT_STALL           5
 #define WDM_POLL_RUNNING        6
-
+#define WDM_RESPONDING          7
+#define WDM_SUSPENDING          8
 
 #define WDM_MAX                 16
 
@@ -87,9 +88,7 @@ struct wdm_device {
         int                     count;
         dma_addr_t              shandle;
         dma_addr_t              ihandle;
-        struct mutex            wlock;
-        struct mutex            rlock;
-        struct mutex            plock;
+        struct mutex            lock;
         wait_queue_head_t       wait;
         struct work_struct      rxwork;
         int                     werr;
@@ -117,21 +116,22 @@ static void wdm_in_callback(struct urb *urb)
         int status = urb->status;
 
         spin_lock(&desc->iuspin);
+        clear_bit(WDM_RESPONDING, &desc->flags);
 
         if (status) {
                 switch (status) {
                 case -ENOENT:
                         dev_dbg(&desc->intf->dev,
                                 "nonzero urb status received: -ENOENT");
-                        break;
+                        goto skip_error;
                 case -ECONNRESET:
                         dev_dbg(&desc->intf->dev,
                                 "nonzero urb status received: -ECONNRESET");
-                        break;
+                        goto skip_error;
                 case -ESHUTDOWN:
                         dev_dbg(&desc->intf->dev,
                                 "nonzero urb status received: -ESHUTDOWN");
-                        break;
+                        goto skip_error;
                 case -EPIPE:
                         dev_err(&desc->intf->dev,
                                 "nonzero urb status received: -EPIPE\n");
@@ -147,6 +147,7 @@ static void wdm_in_callback(struct urb *urb)
         desc->reslength = urb->actual_length;
         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
         desc->length += desc->reslength;
+skip_error:
         wake_up(&desc->wait);
 
         set_bit(WDM_READ, &desc->flags);
@@ -229,13 +230,16 @@ static void wdm_int_callback(struct urb *urb)
         desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
         spin_lock(&desc->iuspin);
         clear_bit(WDM_READ, &desc->flags);
-        if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+        set_bit(WDM_RESPONDING, &desc->flags);
+        if (!test_bit(WDM_DISCONNECTING, &desc->flags)
+                && !test_bit(WDM_SUSPENDING, &desc->flags)) {
                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
                         __func__, rv);
         }
         spin_unlock(&desc->iuspin);
         if (rv < 0) {
+                clear_bit(WDM_RESPONDING, &desc->flags);
                 if (rv == -EPERM)
                         return;
                 if (rv == -ENOMEM) {
@@ -305,14 +309,38 @@ static ssize_t wdm_write
         if (we < 0)
                 return -EIO;
 
-        r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
+        desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
+        if (!buf) {
+                rv = -ENOMEM;
+                goto outnl;
+        }
+
+        r = copy_from_user(buf, buffer, count);
+        if (r > 0) {
+                kfree(buf);
+                rv = -EFAULT;
+                goto outnl;
+        }
+
+        /* concurrent writes and disconnect */
+        r = mutex_lock_interruptible(&desc->lock);
         rv = -ERESTARTSYS;
-        if (r)
+        if (r) {
+                kfree(buf);
                 goto outnl;
+        }
+
+        if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+                kfree(buf);
+                rv = -ENODEV;
+                goto outnp;
+        }
 
         r = usb_autopm_get_interface(desc->intf);
-        if (r < 0)
+        if (r < 0) {
+                kfree(buf);
                 goto outnp;
+        }
 
         if (!file->f_flags && O_NONBLOCK)
                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
@@ -320,24 +348,8 @@ static ssize_t wdm_write
         else
                 if (test_bit(WDM_IN_USE, &desc->flags))
                         r = -EAGAIN;
-        if (r < 0)
-                goto out;
-
-        if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
-                rv = -ENODEV;
-                goto out;
-        }
-
-        desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
-        if (!buf) {
-                rv = -ENOMEM;
-                goto out;
-        }
-
-        r = copy_from_user(buf, buffer, count);
-        if (r > 0) {
+        if (r < 0) {
                 kfree(buf);
-                rv = -EFAULT;
                 goto out;
         }
 
@@ -374,7 +386,7 @@ static ssize_t wdm_write
 out:
         usb_autopm_put_interface(desc->intf);
 outnp:
-        mutex_unlock(&desc->wlock);
+        mutex_unlock(&desc->lock);
 outnl:
         return rv < 0 ? rv : count;
 }
@@ -387,7 +399,7 @@ static ssize_t wdm_read
         struct wdm_device *desc = file->private_data;
 
 
-        rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
+        rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
         if (rv < 0)
                 return -ERESTARTSYS;
 
@@ -424,11 +436,8 @@ retry:
                 spin_lock_irq(&desc->iuspin);
 
                 if (desc->rerr) { /* read completed, error happened */
-                        int t = desc->rerr;
                         desc->rerr = 0;
                         spin_unlock_irq(&desc->iuspin);
-                        dev_err(&desc->intf->dev,
-                                "reading had resulted in %d\n", t);
                         rv = -EIO;
                         goto err;
                 }
@@ -465,9 +474,7 @@ retry:
         rv = cntr;
 
 err:
-        mutex_unlock(&desc->rlock);
-        if (rv < 0 && rv != -EAGAIN)
-                dev_err(&desc->intf->dev, "wdm_read: exit error\n");
+        mutex_unlock(&desc->lock);
         return rv;
 }
 
@@ -533,7 +540,7 @@ static int wdm_open(struct inode *inode, struct file *file)
         }
         intf->needs_remote_wakeup = 1;
 
-        mutex_lock(&desc->plock);
+        mutex_lock(&desc->lock);
         if (!desc->count++) {
                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
                 if (rv < 0) {
@@ -544,7 +551,7 @@ static int wdm_open(struct inode *inode, struct file *file)
         } else {
                 rv = 0;
         }
-        mutex_unlock(&desc->plock);
+        mutex_unlock(&desc->lock);
         usb_autopm_put_interface(desc->intf);
 out:
         mutex_unlock(&wdm_mutex);
@@ -556,9 +563,9 @@ static int wdm_release(struct inode *inode, struct file *file)
         struct wdm_device *desc = file->private_data;
 
         mutex_lock(&wdm_mutex);
-        mutex_lock(&desc->plock);
+        mutex_lock(&desc->lock);
         desc->count--;
-        mutex_unlock(&desc->plock);
+        mutex_unlock(&desc->lock);
 
         if (!desc->count) {
                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
@@ -655,9 +662,7 @@ next_desc:
         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
         if (!desc)
                 goto out;
-        mutex_init(&desc->wlock);
-        mutex_init(&desc->rlock);
-        mutex_init(&desc->plock);
+        mutex_init(&desc->lock);
         spin_lock_init(&desc->iuspin);
         init_waitqueue_head(&desc->wait);
         desc->wMaxCommand = maxcom;
@@ -771,14 +776,17 @@ 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);
-        cancel_work_sync(&desc->rxwork);
+        mutex_lock(&desc->lock);
         kill_urbs(desc);
+        cancel_work_sync(&desc->rxwork);
+        mutex_unlock(&desc->lock);
         wake_up_all(&desc->wait);
         if (!desc->count)
                 cleanup(desc);
         mutex_unlock(&wdm_mutex);
 }
 
+#ifdef CONFIG_PM
 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 {
         struct wdm_device *desc = usb_get_intfdata(intf);
@@ -786,22 +794,30 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 
         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 
-        mutex_lock(&desc->plock);
-#ifdef CONFIG_PM
+        /* if this is an autosuspend the caller does the locking */
+        if (!(message.event & PM_EVENT_AUTO))
+                mutex_lock(&desc->lock);
+        spin_lock_irq(&desc->iuspin);
+
         if ((message.event & PM_EVENT_AUTO) &&
-                        test_bit(WDM_IN_USE, &desc->flags)) {
+                        (test_bit(WDM_IN_USE, &desc->flags)
+                        || test_bit(WDM_RESPONDING, &desc->flags))) {
+                spin_unlock_irq(&desc->iuspin);
                 rv = -EBUSY;
         } else {
-#endif
-                cancel_work_sync(&desc->rxwork);
+
+                set_bit(WDM_SUSPENDING, &desc->flags);
+                spin_unlock_irq(&desc->iuspin);
+                /* callback submits work - order is essential */
                 kill_urbs(desc);
-#ifdef CONFIG_PM
+                cancel_work_sync(&desc->rxwork);
         }
-#endif
-        mutex_unlock(&desc->plock);
+        if (!(message.event & PM_EVENT_AUTO))
+                mutex_unlock(&desc->lock);
 
         return rv;
 }
+#endif
 
 static int recover_from_urb_loss(struct wdm_device *desc)
 {
@@ -815,23 +831,27 @@ static int recover_from_urb_loss(struct wdm_device *desc)
         }
         return rv;
 }
+
+#ifdef CONFIG_PM
 static int wdm_resume(struct usb_interface *intf)
 {
         struct wdm_device *desc = usb_get_intfdata(intf);
         int rv;
 
         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
-        mutex_lock(&desc->plock);
+
+        clear_bit(WDM_SUSPENDING, &desc->flags);
         rv = recover_from_urb_loss(desc);
-        mutex_unlock(&desc->plock);
+
         return rv;
 }
+#endif
 
 static int wdm_pre_reset(struct usb_interface *intf)
 {
         struct wdm_device *desc = usb_get_intfdata(intf);
 
-        mutex_lock(&desc->plock);
+        mutex_lock(&desc->lock);
         return 0;
 }
 
@@ -841,7 +861,7 @@ static int wdm_post_reset(struct usb_interface *intf)
         int rv;
 
         rv = recover_from_urb_loss(desc);
-        mutex_unlock(&desc->plock);
+        mutex_unlock(&desc->lock);
         return 0;
 }
 
@@ -849,9 +869,11 @@ static struct usb_driver wdm_driver = {
         .name =         "cdc_wdm",
         .probe =        wdm_probe,
         .disconnect =   wdm_disconnect,
+#ifdef CONFIG_PM
         .suspend =      wdm_suspend,
         .resume =       wdm_resume,
         .reset_resume = wdm_resume,
+#endif
         .pre_reset =    wdm_pre_reset,
         .post_reset =   wdm_post_reset,
         .id_table =     wdm_ids,