From 556cac064c16f5f2eb17d442c1a78797ad2c962f Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Tue, 3 Sep 2024 21:30:58 -0700 Subject: [PATCH] Input: db9 - use guard notation when acquiring mutex Using guard notation makes the code more compact and error handling more robust by ensuring that mutexes are released in all code paths when control leaves critical section. Link: https://lore.kernel.org/r/20240904043104.1030257-2-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov --- drivers/input/joystick/db9.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) diff --git a/drivers/input/joystick/db9.c b/drivers/input/joystick/db9.c index 6373d7aa739a8..a9f1946cf0d6f 100644 --- a/drivers/input/joystick/db9.c +++ b/drivers/input/joystick/db9.c @@ -505,24 +505,22 @@ static int db9_open(struct input_dev *dev) { struct db9 *db9 = input_get_drvdata(dev); struct parport *port = db9->pd->port; - int err; - err = mutex_lock_interruptible(&db9->mutex); - if (err) - return err; - - if (!db9->used++) { - parport_claim(db9->pd); - parport_write_data(port, 0xff); - if (db9_modes[db9->mode].reverse) { - parport_data_reverse(port); - parport_write_control(port, DB9_NORMAL); + scoped_guard(mutex_intr, &db9->mutex) { + if (!db9->used++) { + parport_claim(db9->pd); + parport_write_data(port, 0xff); + if (db9_modes[db9->mode].reverse) { + parport_data_reverse(port); + parport_write_control(port, DB9_NORMAL); + } + mod_timer(&db9->timer, jiffies + DB9_REFRESH_TIME); } - mod_timer(&db9->timer, jiffies + DB9_REFRESH_TIME); + + return 0; } - mutex_unlock(&db9->mutex); - return 0; + return -EINTR; } static void db9_close(struct input_dev *dev) @@ -530,14 +528,14 @@ static void db9_close(struct input_dev *dev) struct db9 *db9 = input_get_drvdata(dev); struct parport *port = db9->pd->port; - mutex_lock(&db9->mutex); + guard(mutex)(&db9->mutex); + if (!--db9->used) { del_timer_sync(&db9->timer); parport_write_control(port, 0x00); parport_data_forward(port); parport_release(db9->pd); } - mutex_unlock(&db9->mutex); } static void db9_attach(struct parport *pp) -- 2.39.5