Re: leds: just ignore invalid GPIOs in leds-gpio

Re: leds: just ignore invalid GPIOs in leds-gpio

[Geert Uytterhoeven]

On Mon, 6 Apr 2009, Linux Kernel Mailing List wrote:
> Gitweb:     http://git.kernel.org/linus/d379ee8acd0719736ee7f1d1ccc3b5765880eaf8
> Commit:     d379ee8acd0719736ee7f1d1ccc3b5765880eaf8
> Parent:     7fbc3a9b132e93b2ba1fd889c1ad8a4135731cc3
> Author:     David Brownell <dbrownell@users.sourceforge.net>
> AuthorDate: Thu Mar 5 16:46:44 2009 -0800
> Committer:  Richard Purdie <rpurdie@linux.intel.com>
> CommitDate: Mon Apr 6 16:06:27 2009 +0100
> 
>     leds: just ignore invalid GPIOs in leds-gpio
>     
>     Sometimes it's awkward to make sure that the array in the
>     platform_data handed to the leds-gpio driver has only valid
>     data ... some leds may not be always available, and coping
>     with that currently requires patching or rebuilding the array.
>     
>     This patch fixes that by making it be OK to pass an invalid
>     GPIO (such as "-EINVAL") ... such table entries are skipped.
>     
>     [rpurdie@linux.intel.com: adjusted to apply against other led tree changes]
>     Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
>     Tested-by: Diego Dompe <diego.dompe@ridgerun.com>
>     Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
> ---
>  drivers/leds/leds-gpio.c |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
> index 8fa352a..102ef4a 100644
> --- a/drivers/leds/leds-gpio.c
> +++ b/drivers/leds/leds-gpio.c
> @@ -78,6 +78,13 @@ static int __devinit create_gpio_led(const struct gpio_led *template,
>  {
>  	int ret;
>  
> +	/* skip leds that aren't available */
> +	if (!gpio_is_valid(template->gpio)) {
> +		printk(KERN_INFO "Skipping unavilable LED gpio %d (%s)\n", 
> +				template->gpio, template->name);
> +		return;

| drivers/leds/leds-gpio.c:85: warning: 'return' with no value, in function
| returning non-void

So what should we return here? -ENODEV? -EINVAL? Anything else?

> +	}
> +
>  	ret = gpio_request(template->gpio, template->name);
>  	if (ret < 0)
>  		return ret;

With kind regards,

Geert Uytterhoeven
Software Architect

Sony Techsoft Centre Europe
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Re: leds: just ignore invalid GPIOs in leds-gpio

[David Brownell]

On Tuesday 07 April 2009, Geert Uytterhoeven wrote:
> | drivers/leds/leds-gpio.c:85: warning: 'return' with no value, in function
> | returning non-void
> 
> So what should we return here? -ENODEV? -EINVAL? Anything else?

Success:  0.  The point is to ignore them, not fail!


See the appended.

- Dave

========== CUT HERE
From: David Brownell <dbrownell@users.sourceforge.net>

Fix build problems with leds-gpio:

  CC      drivers/leds/leds-gpio.o
drivers/leds/leds-gpio.c: In function 'create_gpio_led':
drivers/leds/leds-gpio.c:85: warning: 'return' with no value, in function returning non-void

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

---
 drivers/leds/leds-gpio.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -82,7 +84,7 @@ static int __devinit create_gpio_led(con
 	if (!gpio_is_valid(template->gpio)) {
 		printk(KERN_INFO "Skipping unavilable LED gpio %d (%s)\n", 
 				template->gpio, template->name);
-		return;
+		return 0;
 	}
 
 	ret = gpio_request(template->gpio, template->name);

Re: leds: just ignore invalid GPIOs in leds-gpio

[Richard Purdie]

On Tue, 2009-04-07 at 17:51 -0700, David Brownell wrote:
> On Tuesday 07 April 2009, Geert Uytterhoeven wrote:
> > | drivers/leds/leds-gpio.c:85: warning: 'return' with no value, in function
> > | returning non-void
> > 
> > So what should we return here? -ENODEV? -EINVAL? Anything else?
> 
> Success:  0.  The point is to ignore them, not fail!
> 
> 
> See the appended.

Agreed. I wondered about returning ENODEV and then catching it in the
calling functions but that doesn't work out as very clear code. I'll
queue and submit this.

Cheers,

Richard