linux-kernel - [PATCH v2] gpiolib: Allow to use setters with return value for output-only gpios

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Message-Id: <20250411-mdb-gpiolib-setters-fix-v2-1-9611280d8822@bootlin.com>
Date: Fri, 11 Apr 2025 16:52:09 +0200
From: Mathieu Dubois-Briand <mathieu.dubois-briand@...tlin.com>
To: Linus Walleij <linus.walleij@...aro.org>, 
 Bartosz Golaszewski <brgl@...ev.pl>, 
 Uwe Kleine-König <u.kleine-koenig@...libre.com>
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 stable@...r.kernel.org, Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 Bartosz Golaszewski <bartosz.golaszewski@...aro.org>, 
 Mathieu Dubois-Briand <mathieu.dubois-briand@...tlin.com>
Subject: [PATCH v2] gpiolib: Allow to use setters with return value for
 output-only gpios

The gpiod_direction_output_raw_commit() function checks if any setter
callback is present before doing anything. As the new GPIO setters with
return values were introduced, make this check also succeed if one is
present.

Fixes: 98ce1eb1fd87 ("gpiolib: introduce gpio_chip setters that return values")
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@...tlin.com>
---
Changes in v2:
- Add Fixes: tag and Cc: to stable
- Link to v1: https://lore.kernel.org/r/20250411-mdb-gpiolib-setters-fix-v1-1-dea302ab7440@bootlin.com
---
 drivers/gpio/gpiolib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b8197502a5ac..cd4fecbb41f2 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2879,7 +2879,7 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
 	 * output-only, but if there is then not even a .set() operation it
 	 * is pretty tricky to drive the output line.
 	 */
-	if (!guard.gc->set && !guard.gc->direction_output) {
+	if (!guard.gc->set && !guard.gc->set_rv && !guard.gc->direction_output) {
 		gpiod_warn(desc,
 			   "%s: missing set() and direction_output() operations\n",
 			   __func__);

---
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
change-id: 20250411-mdb-gpiolib-setters-fix-b87976992070

Best regards,
-- 
Mathieu Dubois-Briand <mathieu.dubois-briand@...tlin.com>