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authorTomas Winkler <tomas.winkler@intel.com>2017-03-05 20:40:41 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-16 02:47:53 +0100
commita733ded50b6ea846200073e7381a302df71e13b3 (patch)
treec607f1208e4cd54539e099d5dab4772e56e1beb5
parentMerge tag 'stm-fixes-for-greg-20170315' of git://git.kernel.org/pub/scm/linux... (diff)
downloadlinux-a733ded50b6ea846200073e7381a302df71e13b3.tar.xz
linux-a733ded50b6ea846200073e7381a302df71e13b3.zip
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>
-rw-r--r--drivers/misc/mei/init.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index cfb1cdf176fa..13c55b8f9261 100644
--- 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_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;