dmaengine: at_hdmac: Fix concurrency over the active list

stable inclusion
from stable-v5.10.155
commit a35dd5dd98b67b98f57e55efb4374e55c2cb680f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7M5F4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a35dd5dd98b67b98f57e55efb4374e55c2cb680f



--------------------------------

commit 03ed9ba3 upstream.

The tasklet (atc_advance_work()) did not held the channel lock when
retrieving the first active descriptor, causing concurrency problems if
issue_pending() was called in between. If issue_pending() was called
exactly after the lock was released in the tasklet (atc_advance_work()),
atc_chain_complete() could complete a descriptor for which the controller
has not yet raised an interrupt.

Fixes: dc78baa2 ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/


Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-11-tudor.ambarus@microchip.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>