From a0fa2206f550066d6948d43c5401e973e5f7d320 Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Wed, 23 Mar 2011 23:48:19 -0700 Subject: [PATCH] Input: tsc2005 - fix locking issue Commit 0b950d3 (Input: tsc2005 - add open/close) introduced a locking issue with the ESD watchdog: __tsc2005_disable() is calling cancel_delayed_work_sync() with mutex held, and the work also needs the same mutex. Fix the problem by using mutex_trylock() in tsc2005_esd_work(). If the mutex is taken, we know we are in the middle of disable or enable and the watchdog check can be skipped. Signed-off-by: Aaro Koskinen Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/tsc2005.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/input/touchscreen/tsc2005.c b/drivers/input/touchscreen/tsc2005.c index 2a9a7260fe8..cbf0ff32267 100644 --- a/drivers/input/touchscreen/tsc2005.c +++ b/drivers/input/touchscreen/tsc2005.c @@ -477,7 +477,14 @@ static void tsc2005_esd_work(struct work_struct *work) int error; u16 r; - mutex_lock(&ts->mutex); + if (!mutex_trylock(&ts->mutex)) { + /* + * If the mutex is taken, it means that disable or enable is in + * progress. In that case just reschedule the work. If the work + * is not needed, it will be canceled by disable. + */ + goto reschedule; + } if (time_is_after_jiffies(ts->last_valid_interrupt + msecs_to_jiffies(ts->esd_timeout))) @@ -510,11 +517,12 @@ static void tsc2005_esd_work(struct work_struct *work) tsc2005_start_scan(ts); out: + mutex_unlock(&ts->mutex); +reschedule: /* re-arm the watchdog */ schedule_delayed_work(&ts->esd_work, round_jiffies_relative( msecs_to_jiffies(ts->esd_timeout))); - mutex_unlock(&ts->mutex); } static int tsc2005_open(struct input_dev *input) -- 2.20.1