p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

mei: fix deadlock on mei reset 

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.

Cc: <stable@vger.kernel.org> #4.10+
Fixes: f302bb0de6ac (mei: synchronize irq before initiating a reset)
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tomas Winkler 2017-03-05 21:40:41 +02:00 committed by Greg Kroah-Hartman
parent 603980cecc
commit a733ded50b
1 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/misc/mei/init.c
View File

@ -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_struct *work)
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;