linux-stable/drivers/usb/class
Jerome Brunet 38203b8385 usb: cdc-acm: fix cooldown mechanism
Commit a4e7279cd1 ("cdc-acm: introduce a cool down") is causing
regression if there is some USB error, such as -EPROTO.

This has been reported on some samples of the Odroid-N2 using the Combee II
Zibgee USB dongle.

> struct acm *acm = container_of(work, struct acm, work)

is incorrect in case of a delayed work and causes warnings, usually from
the workqueue:

> WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:1474 __queue_work+0x480/0x528.

When this happens, USB eventually stops working completely after a while.
Also the ACM_ERROR_DELAY bit is never set, so the cooldown mechanism
previously introduced cannot be triggered and acm_submit_read_urb() is
never called.

This changes makes the cdc-acm driver use a single delayed work, fixing the
pointer arithmetic in acm_softint() and set the ACM_ERROR_DELAY when the
cooldown mechanism appear to be needed.

Fixes: a4e7279cd1 ("cdc-acm: introduce a cool down")
Cc: Oliver Neukum <oneukum@suse.com>
Reported-by: Pascal Vizeli <pascal.vizeli@nabucasa.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201019170702.150534-1-jbrunet@baylibre.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-28 13:20:21 +01:00
..
cdc-acm.c usb: cdc-acm: fix cooldown mechanism 2020-10-28 13:20:21 +01:00
cdc-acm.h usb: cdc-acm: fix cooldown mechanism 2020-10-28 13:20:21 +01:00
cdc-wdm.c USB: cdc-wdm: Make wdm_flush() interruptible and add wdm_fsync(). 2020-10-02 11:30:10 +02:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile USB: add SPDX identifiers to all remaining Makefiles 2017-11-07 15:53:48 +01:00
usblp.c usblp: fix race between disconnect() and read() 2020-09-17 18:45:30 +02:00
usbtmc.c usb: Use fallthrough pseudo-keyword 2020-07-10 08:55:17 +02:00