[PATCH 3/5] Input: ads7846 - remove unneeded memory barriers

The driver invokes mb() after setting the stopped flag in ads7846_stop()
and ads7846_restart(). These mandatory barriers lack pairing barriers on
the reader side and are unnecessary.

The wait queue operations wake_up() and wait_event_timeout(), along
with disable_irq() and enable_irq(), already provide the required
synchronization and memory ordering when stopping and restarting the
device polling. Remove the redundant barriers.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/touchscreen/ads7846.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index f1827684c902..6352117cd898 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c

@@ -235,7 +235,6 @@ static void ads7846_stop(struct ads7846 *ts)
 	if (!ts->disabled && !ts->suspended) {
 		/* Signal IRQ thread to stop polling and disable the handler. */
 		ts->stopped = true;
-		mb();
 		wake_up(&ts->wait);
 		disable_irq(ts->spi->irq);
 	}

@@ -251,7 +250,6 @@ static void ads7846_restart(struct ads7846 *ts)
 
 		/* Tell IRQ thread that it may poll the device. */
 		ts->stopped = false;
-		mb();
 		enable_irq(ts->spi->irq);
 	}
 }

-- 
2.56.0.567.gdb80ae8cd5-goog