[PATCH v3 1/3] iio: ssp_sensors: ssp_spi: use guard() to release mutexes

Sanjay Chitroda
2026-03-15T12:55:18Z

From: Sanjay Chitroda <sanjayembeddedse@gmail.com>

Replace explicit mutex_lock() and mutex_unlock() with the guard() macro
for cleaner and safer mutex handling.

Signed-off-by: Sanjay Chitroda <sanjayembeddedse@gmail.com>
---
drivers/iio/common/ssp_sensors/ssp_spi.c | 54 ++++++++++--------------
1 file changed, 22 insertions(+), 32 deletions(-)

diff --git a/drivers/iio/common/ssp_sensors/ssp_spi.c b/drivers/iio/common/ssp_sensors/ssp_spi.c
index 6c81c0385fb5..87a38002b218 100644
--- a/drivers/iio/common/ssp_sensors/ssp_spi.c
+++ b/drivers/iio/common/ssp_sensors/ssp_spi.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2014, Samsung Electronics Co. Ltd. All Rights Reserved.
*/
+#include <linux/cleanup.h>

#include "ssp.h"

@@ -189,55 +190,49 @@ static int ssp_do_transfer(struct ssp_data *data, struct ssp_msg *msg,

msg->done = done;

- mutex_lock(&data->comm_lock);
+ guard(mutex)(&data->comm_lock);

status = ssp_check_lines(data, false);
- if (status < 0)
- goto _error_locked;
+ if (status < 0) {
+ data->timeout_cnt++;
+ return status;
+ }

status = spi_write(data->spi, msg->buffer, SSP_HEADER_SIZE);
if (status < 0) {
gpiod_set_value_cansleep(data->ap_mcu_gpiod, 1);
dev_err(SSP_DEV, "%s spi_write fail\n", __func__);
- goto _error_locked;
+ data->timeout_cnt++;
+ return status;
}

if (!use_no_irq) {
- mutex_lock(&data->pending_lock);
- list_add_tail(&msg->list, &data->pending_list);
- mutex_unlock(&data->pending_lock);
+ scoped_guard(mutex, &data->pending_lock)
+ list_add_tail(&msg->list, &data->pending_list);
}

status = ssp_check_lines(data, true);
if (status < 0) {
if (!use_no_irq) {
- mutex_lock(&data->pending_lock);
- list_del(&msg->list);
- mutex_unlock(&data->pending_lock);
+ scoped_guard(mutex, &data->pending_lock)
+ list_add_tail(&msg->list, &data->pending_list);
}
- goto _error_locked;
+ data->timeout_cnt++;
+ return status;
}

- mutex_unlock(&data->comm_lock);
-
if (!use_no_irq && done)
if (wait_for_completion_timeout(done,
msecs_to_jiffies(timeout)) ==
0) {
- mutex_lock(&data->pending_lock);
- list_del(&msg->list);
- mutex_unlock(&data->pending_lock);
+ scoped_guard(mutex, &data->pending_lock)
+ list_add_tail(&msg->list, &data->pending_list);

data->timeout_cnt++;
return -ETIMEDOUT;
}

return 0;
-
-_error_locked:
- mutex_unlock(&data->comm_lock);
- data->timeout_cnt++;
- return status;
}

static inline int ssp_spi_sync_command(struct ssp_data *data,
@@ -360,7 +355,7 @@ int ssp_irq_msg(struct ssp_data *data)
* this is a small list, a few elements - the packets can be
* received with no order
*/
- mutex_lock(&data->pending_lock);
+ guard(mutex)(&data->pending_lock);
list_for_each_entry_safe(iter, n, &data->pending_list, list) {
if (iter->options == msg_options) {
list_del(&iter->list);
@@ -376,10 +371,8 @@ int ssp_irq_msg(struct ssp_data *data)
* check but let's handle this
*/
buffer = kmalloc(length, GFP_KERNEL | GFP_DMA);
- if (!buffer) {
- ret = -ENOMEM;
- goto _unlock;
- }
+ if (!buffer)
+ return -ENOMEM;

/* got dead packet so it is always an error */
ret = spi_read(data->spi, buffer, length);
@@ -391,7 +384,7 @@ int ssp_irq_msg(struct ssp_data *data)
dev_err(SSP_DEV, "No match error %x\n",
msg_options);

- goto _unlock;
+ return ret;
}

if (msg_type == SSP_AP2HUB_READ)
@@ -409,15 +402,13 @@ int ssp_irq_msg(struct ssp_data *data)
msg->length = 1;

list_add_tail(&msg->list, &data->pending_list);
- goto _unlock;
+ return ret;
}
}

if (msg->done)
if (!completion_done(msg->done))
complete(msg->done);
-_unlock:
- mutex_unlock(&data->pending_lock);
break;
case SSP_HUB2AP_WRITE:
buffer = kzalloc(length, GFP_KERNEL | GFP_DMA);
@@ -448,7 +439,7 @@ void ssp_clean_pending_list(struct ssp_data *data)
{
struct ssp_msg *msg, *n;

- mutex_lock(&data->pending_lock);
+ guard(mutex)(&data->pending_lock);
list_for_each_entry_safe(msg, n, &data->pending_list, list) {
list_del(&msg->list);

@@ -456,7 +447,6 @@ void ssp_clean_pending_list(struct ssp_data *data)
if (!completion_done(msg->done))
complete(msg->done);
}
- mutex_unlock(&data->pending_lock);
}

int ssp_command(struct ssp_data *data, char command, int arg)
--
2.34.1