From 868d163aec12bf48fccbf15fd9cf06a55b744317 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Tue, 3 Sep 2024 21:49:29 -0700 Subject: [PATCH] Input: rotary_encoder - 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. Reviewed-by: Javier Carrasco Link: https://lore.kernel.org/r/20240904044929.1049700-1-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov --- drivers/input/misc/rotary_encoder.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index e94cab8133be..f706e1997417 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -106,7 +106,7 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) struct rotary_encoder *encoder = dev_id; unsigned int state; - mutex_lock(&encoder->access_mutex); + guard(mutex)(&encoder->access_mutex); state = rotary_encoder_get_state(encoder); @@ -129,8 +129,6 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) break; } - mutex_unlock(&encoder->access_mutex); - return IRQ_HANDLED; } @@ -139,7 +137,7 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) struct rotary_encoder *encoder = dev_id; unsigned int state; - mutex_lock(&encoder->access_mutex); + guard(mutex)(&encoder->access_mutex); state = rotary_encoder_get_state(encoder); @@ -152,8 +150,6 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) } } - mutex_unlock(&encoder->access_mutex); - return IRQ_HANDLED; } @@ -162,22 +158,19 @@ static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id) struct rotary_encoder *encoder = dev_id; unsigned int state; - mutex_lock(&encoder->access_mutex); + guard(mutex)(&encoder->access_mutex); state = rotary_encoder_get_state(encoder); - if ((encoder->last_stable + 1) % 4 == state) + if ((encoder->last_stable + 1) % 4 == state) { encoder->dir = 1; - else if (encoder->last_stable == (state + 1) % 4) + rotary_encoder_report_event(encoder); + } else if (encoder->last_stable == (state + 1) % 4) { encoder->dir = -1; - else - goto out; - - rotary_encoder_report_event(encoder); + rotary_encoder_report_event(encoder); + } -out: encoder->last_stable = state; - mutex_unlock(&encoder->access_mutex); return IRQ_HANDLED; } -- 2.50.1