[PATCH V3] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails

[PATCH V3] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails

[Stefan Wahren]

In case leds-gpio fails to get at least one of possibly many GPIOs
from the DT (e.g. the GPIO is already requested) neither gpiolib nor
the driver does provide any helpful error log:

    leds-gpio: probe of leds failed with error -16

As the driver knows better how to handle errors with such mandatory
GPIOs, let's implement an error log which points to the affected
GPIO.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---

Previous discussion:
https://lore.kernel.org/linux-leds/20231201112330.GD3259151@google.com/T/

Changes in V3:
- drop already applied patch from series
- s/gpio/GPIO/ as suggested by Lee Jones
- improve commit message

Changes in V2:
- replace dev_err with dev_err_probe to handle EPROBE_DEFER properly

 drivers/leds/leds-gpio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 710c319ad312..83fcd7b6afff 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -172,6 +172,8 @@ static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
 		led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS,
 						  NULL);
 		if (IS_ERR(led.gpiod)) {
+			dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n",
+				      child);
 			fwnode_handle_put(child);
 			return ERR_CAST(led.gpiod);
 		}
--
2.34.1

Re: [PATCH V3] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails

[Linus Walleij]

On Sat, Dec 2, 2023 at 7:37 PM Stefan Wahren <wahrenst@gmx.net> wrote:

> In case leds-gpio fails to get at least one of possibly many GPIOs
> from the DT (e.g. the GPIO is already requested) neither gpiolib nor
> the driver does provide any helpful error log:
>
>     leds-gpio: probe of leds failed with error -16
>
> As the driver knows better how to handle errors with such mandatory
> GPIOs, let's implement an error log which points to the affected
> GPIO.
>
> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH V3] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails

[Andy Shevchenko]

On Sat, Dec 02, 2023 at 07:36:36PM +0100, Stefan Wahren wrote:
> In case leds-gpio fails to get at least one of possibly many GPIOs
> from the DT (e.g. the GPIO is already requested) neither gpiolib nor
> the driver does provide any helpful error log:
> 
>     leds-gpio: probe of leds failed with error -16
> 
> As the driver knows better how to handle errors with such mandatory
> GPIOs, let's implement an error log which points to the affected
> GPIO.

As we have had a consensus,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko

Re: (subset) [PATCH V3] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails

[Lee Jones]

On Sat, 02 Dec 2023 19:36:36 +0100, Stefan Wahren wrote:
> In case leds-gpio fails to get at least one of possibly many GPIOs
> from the DT (e.g. the GPIO is already requested) neither gpiolib nor
> the driver does provide any helpful error log:
> 
>     leds-gpio: probe of leds failed with error -16
> 
> As the driver knows better how to handle errors with such mandatory
> GPIOs, let's implement an error log which points to the affected
> GPIO.
> 
> [...]

Applied, thanks!

[1/1] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails
      commit: 430545cd13d0f554aaadb8b938ac0bdf7a70a413

--
Lee Jones [李琼斯]