usb: cdc-wdm: Fix submission of URB after suspension

There's a window under which cdc-wdm may submit
an URB to a device about to be suspended. This
introduces a flag to prevent it.

Signed-off-by: Oliver Neukum <neukum@b1-systems.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 72e2eb0..a6b5e9f 100644 (file)
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -53,7 +53,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
 #define WDM_INT_STALL          5
 #define WDM_POLL_RUNNING       6
 #define WDM_RESPONDING         7
-
+#define WDM_SUSPENDING         8
 
 #define WDM_MAX                        16
 
@@ -231,7 +231,8 @@ static void wdm_int_callback(struct urb *urb)
        spin_lock(&desc->iuspin);
        clear_bit(WDM_READ, &desc->flags);
        set_bit(WDM_RESPONDING, &desc->flags);
-       if (!test_bit(WDM_DISCONNECTING, &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);
@@ -800,6 +801,7 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
                rv = -EBUSY;
        } else {
 #endif
+               set_bit(WDM_SUSPENDING, &desc->flags);
                cancel_work_sync(&desc->rxwork);
                kill_urbs(desc);
 #ifdef CONFIG_PM
@@ -830,6 +832,7 @@ static int wdm_resume(struct usb_interface *intf)
        dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
        mutex_lock(&desc->lock);
        rv = recover_from_urb_loss(desc);
+       clear_bit(WDM_SUSPENDING, &desc->flags);
        mutex_unlock(&desc->lock);
        return rv;
 }