This is a note to let you know that I've just added the patch titled
mei: fix deadlock on mei reset
to the 4.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mei-fix-deadlock-on-mei-reset.patch
and it can be found in the queue-4.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a733ded50b6ea846200073e7381a302df71e13b3 Mon Sep 17 00:00:00 2001
From: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Date: Sun, 5 Mar 2017 21:40:41 +0200
Subject: mei: fix deadlock on mei reset
From: Tomas Winkler <tomas.winkler@xxxxxxxxx>
commit a733ded50b6ea846200073e7381a302df71e13b3 upstream.
This patch fixes 'mei: synchronize irq before initiating a reset'
The patch had introduced a deadlock between irq thread and mei_reset()
as they are both holding the same device lock.
---> device_lock:
mei_reset()
<---- interrupt thread
device_lock
---> synchornize_irq()
wait on interrupt thread == (dead lock)
The fix is to call synchronize_irq
prior to call locked mei_reset function.
Fixes: f302bb0de6ac (mei: synchronize irq before initiating a reset)
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/mei/init.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -124,8 +124,6 @@ int mei_reset(struct mei_device *dev)
mei_clear_interrupts(dev);
- mei_synchronize_irq(dev);
-
/* we're already in reset, cancel the init timer
* if the reset was called due the hbm protocol error
* we need to call it before hw start
@@ -304,6 +302,9 @@ static void mei_reset_work(struct work_s
container_of(work, struct mei_device, reset_work);
int ret;
+ mei_clear_interrupts(dev);
+ mei_synchronize_irq(dev);
+
mutex_lock(&dev->device_lock);
ret = mei_reset(dev);
@@ -328,6 +329,9 @@ void mei_stop(struct mei_device *dev)
mei_cancel_work(dev);
+ mei_clear_interrupts(dev);
+ mei_synchronize_irq(dev);
+
mutex_lock(&dev->device_lock);
dev->dev_state = MEI_DEV_POWER_DOWN;
Patches currently in stable-queue which might be from tomas.winkler@xxxxxxxxx are
queue-4.10/mei-fix-deadlock-on-mei-reset.patch
queue-4.10/mei-don-t-wait-for-os-version-message-reply.patch