[PATCH 2/2] Input: i8042 - Lock i8042_mutex before flushing

From: Raul E Rangel
Date: Thu Aug 27 2020 - 15:52:55 EST


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 <rrangel@xxxxxxxxxxxx>
---

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 8590e51bcc087..b693154641500 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