>From c37d436b8832e817ab437baa3324f6c08c846af9 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@xxxxxxx>
Date: Fri, 16 Jan 2015 15:13:28 +0100
Subject: [PATCH] cdc-wdm: bug in ceasing IO
The work submits the URB and the URB queues the work.
To reliably kill this cycle a flag needs to be set
and one of the kills repeated.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
---
drivers/usb/class/cdc-wdm.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 5ff7018..e24bad6 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -976,8 +976,10 @@ static void wdm_disconnect(struct usb_interface *intf)
wake_up_all(&desc->wait);
mutex_lock(&desc->rlock);
mutex_lock(&desc->wlock);
+ /* circular dependency. The second kill is needed */
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
+ kill_urbs(desc);
mutex_unlock(&desc->wlock);
mutex_unlock(&desc->rlock);
@@ -1017,9 +1019,10 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
set_bit(WDM_SUSPENDING, &desc->flags);
spin_unlock_irq(&desc->iuspin);
- /* callback submits work - order is essential */
+ /* circular dependency. The second kill is needed */
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
+ kill_urbs(desc);
}
if (!PMSG_IS_AUTO(message)) {
mutex_unlock(&desc->wlock);
@@ -1077,8 +1080,10 @@ static int wdm_pre_reset(struct usb_interface *intf)
wake_up_all(&desc->wait);
mutex_lock(&desc->rlock);
mutex_lock(&desc->wlock);
+ /* circular dependency. The second kill is needed */
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
+ kill_urbs(desc);
return 0;
}
--
1.8.4.5
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