[PATCH 21/22] Input: rotary_encoder - use guard notation when acquiring mutex
From: Dmitry Torokhov
Date: Wed Sep 04 2024 - 00:50:15 EST
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.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
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 6628fe540834..52761da9f999 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -113,7 +113,7 @@ 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);
@@ -136,8 +136,6 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
break;
}
- mutex_unlock(&encoder->access_mutex);
-
return IRQ_HANDLED;
}
@@ -146,7 +144,7 @@ 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);
@@ -159,8 +157,6 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
}
}
- mutex_unlock(&encoder->access_mutex);
-
return IRQ_HANDLED;
}
@@ -169,22 +165,19 @@ 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;
}
--
2.46.0.469.g59c65b2a67-goog