From a0fa2206f550066d6948d43c5401e973e5f7d320 Mon Sep 17 00:00:00 2001
From: Aaro Koskinen <aaro.koskinen@nokia.com>
Date: Wed, 23 Mar 2011 23:48:19 -0700
Subject: 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 <aaro.koskinen@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
drivers/input/touchscreen/tsc2005.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
(limited to 'drivers')
diff --git a/drivers/input/touchscreen/tsc2005.c b/drivers/input/touchscreen/tsc2005.c
index 2a9a7260fe8e..cbf0ff322676 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)
--
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