[PATCH] leds: leds-gpio: Pass on error codes unmodified

[PATCH] leds: leds-gpio: Pass on error codes unmodified

[Soren Brinkmann]

Instead of overriding error codes, pass them on unmodified. This
way a EPROBE_DEFER is correctly passed to the driver core. This results
in the LED driver correctly requesting probe deferral in cases the GPIO
controller is not yet available.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
---
Adding pinctrl on Zynq shuffled with probing order quite a bit and a lot
of deferred probing is going on. With those changes I saw the LEDs
failing to probe due to the GPIO controller deferring probe until the
pincontroller is available. With this patch things work again:

dmesg | grep -i led:
  of_get_named_gpiod_flags: parsed 'gpios' property of node '/leds/ds23[0]' - status (-517)
  platform leds: Driver leds-gpio requests probe deferral
  of_get_named_gpiod_flags: parsed 'gpios' property of node '/leds/ds23[0]' - status (0)

  	Soren
---
 drivers/leds/leds-gpio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 7ea1ea42c2d2..d26af0a79a90 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -187,6 +187,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
 		led.gpiod = devm_get_gpiod_from_child(dev, child);
 		if (IS_ERR(led.gpiod)) {
 			fwnode_handle_put(child);
+			ret = PTR_ERR(led.gpiod);
 			goto err;
 		}
 
@@ -229,7 +230,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
 err:
 	for (count = priv->num_leds - 2; count >= 0; count--)
 		delete_gpio_led(&priv->leds[count]);
-	return ERR_PTR(-ENODEV);
+	return ERR_PTR(ret);
 }
 
 static const struct of_device_id of_gpio_leds_match[] = {
-- 
2.2.2.1.g63c5777

Re: [PATCH] leds: leds-gpio: Pass on error codes unmodified

[Sören Brinkmann]

+ Andreas who actually reported this issue and also tested the patch.

On Sat, 2015-01-31 at 07:15PM -0800, Soren Brinkmann wrote:
> Instead of overriding error codes, pass them on unmodified. This
> way a EPROBE_DEFER is correctly passed to the driver core. This results
> in the LED driver correctly requesting probe deferral in cases the GPIO
> controller is not yet available.
> 
> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

Here should be a:
Reported-and-tested-by: Andreas Färber <afaerber@suse.de>

> ---
> Adding pinctrl on Zynq shuffled with probing order quite a bit and a lot
> of deferred probing is going on. With those changes I saw the LEDs
> failing to probe due to the GPIO controller deferring probe until the
> pincontroller is available. With this patch things work again:
> 
> dmesg | grep -i led:
>   of_get_named_gpiod_flags: parsed 'gpios' property of node '/leds/ds23[0]' - status (-517)
>   platform leds: Driver leds-gpio requests probe deferral
>   of_get_named_gpiod_flags: parsed 'gpios' property of node '/leds/ds23[0]' - status (0)
> 
>   	Soren
> ---
>  drivers/leds/leds-gpio.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
> index 7ea1ea42c2d2..d26af0a79a90 100644
> --- a/drivers/leds/leds-gpio.c
> +++ b/drivers/leds/leds-gpio.c
> @@ -187,6 +187,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
>  		led.gpiod = devm_get_gpiod_from_child(dev, child);
>  		if (IS_ERR(led.gpiod)) {
>  			fwnode_handle_put(child);
> +			ret = PTR_ERR(led.gpiod);
>  			goto err;
>  		}
>  
> @@ -229,7 +230,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
>  err:
>  	for (count = priv->num_leds - 2; count >= 0; count--)
>  		delete_gpio_led(&priv->leds[count]);
> -	return ERR_PTR(-ENODEV);
> +	return ERR_PTR(ret);
>  }
>  
>  static const struct of_device_id of_gpio_leds_match[] = {
> -- 
> 2.2.2.1.g63c5777
> 

Re: [PATCH] leds: leds-gpio: Pass on error codes unmodified

[Bryan Wu]

On Sun, Feb 1, 2015 at 8:59 AM, Sören Brinkmann
<soren.brinkmann@xilinx.com> wrote:
> + Andreas who actually reported this issue and also tested the patch.
>
> On Sat, 2015-01-31 at 07:15PM -0800, Soren Brinkmann wrote:
>> Instead of overriding error codes, pass them on unmodified. This
>> way a EPROBE_DEFER is correctly passed to the driver core. This results
>> in the LED driver correctly requesting probe deferral in cases the GPIO
>> controller is not yet available.
>>
>> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
>
> Here should be a:
> Reported-and-tested-by: Andreas Färber <afaerber@suse.de>
>

Good catch. I merged it to my tree.

Thanks,
-Bryan

>> ---
>> Adding pinctrl on Zynq shuffled with probing order quite a bit and a lot
>> of deferred probing is going on. With those changes I saw the LEDs
>> failing to probe due to the GPIO controller deferring probe until the
>> pincontroller is available. With this patch things work again:
>>
>> dmesg | grep -i led:
>>   of_get_named_gpiod_flags: parsed 'gpios' property of node '/leds/ds23[0]' - status (-517)
>>   platform leds: Driver leds-gpio requests probe deferral
>>   of_get_named_gpiod_flags: parsed 'gpios' property of node '/leds/ds23[0]' - status (0)
>>
>>       Soren
>> ---
>>  drivers/leds/leds-gpio.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
>> index 7ea1ea42c2d2..d26af0a79a90 100644
>> --- a/drivers/leds/leds-gpio.c
>> +++ b/drivers/leds/leds-gpio.c
>> @@ -187,6 +187,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
>>               led.gpiod = devm_get_gpiod_from_child(dev, child);
>>               if (IS_ERR(led.gpiod)) {
>>                       fwnode_handle_put(child);
>> +                     ret = PTR_ERR(led.gpiod);
>>                       goto err;
>>               }
>>
>> @@ -229,7 +230,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
>>  err:
>>       for (count = priv->num_leds - 2; count >= 0; count--)
>>               delete_gpio_led(&priv->leds[count]);
>> -     return ERR_PTR(-ENODEV);
>> +     return ERR_PTR(ret);
>>  }
>>
>>  static const struct of_device_id of_gpio_leds_match[] = {
>> --
>> 2.2.2.1.g63c5777
>>