From a733ded50b6ea846200073e7381a302df71e13b3 Mon Sep 17 00:00:00 2001 From: Tomas Winkler Date: Sun, 5 Mar 2017 21:40:41 +0200 Subject: [PATCH] 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: #4.10+ Fixes: f302bb0de6ac (mei: synchronize irq before initiating a reset) Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/init.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c index cfb1cdf..13c55b8 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; -- 2.7.4