[PATCH v8 02/12] iio: ssp_sensors: factor out pending list add/remove helpers

[Sanjay Chitroda <sanjayembeddedse@gmail.com>]

From: Sanjay Chitroda <sanjayembeddedse@gmail.com>

The SSP SPI transfer path manipulates the pending message list in
multiple places, open-coding the same locking and list operations.

Refactor the pending list add and remove logic into helper functions.
This reduces duplication and simplifies the transfer flow by
centralizing the pending list handling.

No functional change intended.

Signed-off-by: Sanjay Chitroda <sanjayembeddedse@gmail.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
---
Changes in v8:
- Following discussion with Andy and Jonathan, handle the flag
  and have preparatory changes for subfunction help of critical section
- v7 change: https://lore.kernel.org/all/20260426091710.3722035-3-sanjayembedded@gmail.com/
Changes in v7:
- Following suggestion from Andy, keep helper API definition in single
  line and re-place the comment section
- v6 change: https://lore.kernel.org/all/20260415050749.3858046-4-sanjayembedded@gmail.com/
Changes in v6:
- Include tag for the suggestion of helper functions
- Drop completely use_no_irq variable with review comment from Andy
- v5 change: https://lore.kernel.org/all/20260406080852.2727453-4-sanjayembedded@gmail.com/
---
 drivers/iio/common/ssp_sensors/ssp_spi.c | 50 ++++++++++++++----------
 1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/common/ssp_sensors/ssp_spi.c b/drivers/iio/common/ssp_sensors/ssp_spi.c
index 08ed92859be0..3d377a482161 100644
--- a/drivers/iio/common/ssp_sensors/ssp_spi.c
+++ b/drivers/iio/common/ssp_sensors/ssp_spi.c
@@ -174,6 +174,28 @@ static int ssp_check_lines(struct ssp_data *data, bool state)
 	return 0;
 }
 
+static inline void ssp_pending_add(struct ssp_data *data, struct ssp_msg *msg,
+				   bool no_irq)
+{
+	if (no_irq)
+		return;
+
+	mutex_lock(&data->pending_lock);
+	list_add_tail(&msg->list, &data->pending_list);
+	mutex_unlock(&data->pending_lock);
+}
+
+static inline void ssp_pending_del(struct ssp_data *data, struct ssp_msg *msg,
+				   bool no_irq)
+{
+	if (no_irq)
+		return;
+
+	mutex_lock(&data->pending_lock);
+	list_del(&msg->list);
+	mutex_unlock(&data->pending_lock);
+}
+
 static int ssp_do_transfer(struct ssp_data *data, struct ssp_msg *msg,
 			   struct completion *done, int timeout)
 {
@@ -202,35 +224,23 @@ static int ssp_do_transfer(struct ssp_data *data, struct ssp_msg *msg,
 		goto _error_locked;
 	}
 
-	if (!use_no_irq) {
-		mutex_lock(&data->pending_lock);
-		list_add_tail(&msg->list, &data->pending_list);
-		mutex_unlock(&data->pending_lock);
-	}
+	ssp_pending_add(data, msg, use_no_irq);
 
 	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);
-		}
+		ssp_pending_del(data, msg, use_no_irq);
 		goto _error_locked;
 	}
 
 	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);
+	if (!use_no_irq && done &&
+	    !wait_for_completion_timeout(done, msecs_to_jiffies(timeout))) {
+		ssp_pending_del(data, msg, use_no_irq);
 
-			data->timeout_cnt++;
-			return -ETIMEDOUT;
-		}
+		data->timeout_cnt++;
+		return -ETIMEDOUT;
+	}
 
 	return 0;
 
-- 
2.34.1