Make i8042_flush lock the i8042_mutex before flushing the buffer. This
will prevent i8042_flush from clearing the buffer while a PS/2 command is
in progress. I'm not sure if this is really possible. We already
hold the lock when calling i8042_command, so this makes i8042_flush have
the same behavior.

Signed-off-by: Raul E Rangel <redacted>
---

(no changes since v1)

 drivers/input/serio/i8042.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 65ca6b47f41e8..b7ed93c5095c4 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c

@@ -254,6 +254,8 @@ static int i8042_flush(void)
 	int count = 0;
 	int retval = 0;
 
+	mutex_lock(&i8042_mutex);
+
 	spin_lock_irqsave(&i8042_lock, flags);
 
 	while ((str = i8042_read_status()) & I8042_STR_OBF) {

@@ -270,6 +272,8 @@ static int i8042_flush(void)
 
 	spin_unlock_irqrestore(&i8042_lock, flags);
 
+	mutex_unlock(&i8042_mutex);
+
 	return retval;
 }
 

-- 
2.28.0.297.g1956fa8f8d-goog