On Thu, Nov 06, 2014 at 12:12:04PM +0100, Geert Uytterhoeven wrote:
> Hi Mika,
>
> On Thu, Nov 6, 2014 at 11:58 AM, Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> > On Thu, Nov 06, 2014 at 11:32:19AM +0100, Geert Uytterhoeven wrote:
> >> On Thu, Nov 6, 2014 at 11:30 AM, Mika Westerberg
> >> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> >> >> "leds: leds-gpio: Add support for GPIO descriptors" broke leds-gpio on
> >> >> non-DT platforms for me:
> >> >>
> >> >> gpiod_direction_output: invalid GPIO
> >> >> leds-gpio: probe of leds-gpio failed with error -22
> >> >>
> >> >> (desc is NULL in gpiod_direction_output()).
> >> >>
> >> >> DT shmobile reference/multi-platform are fine.
> >> >>
> >> >> I noticed the hard way, as I wanted to add some LEDs to a new platform,
> >> >> but couldn't get it work. It turned out it also had stopped working on
> >> >> r8a7740/armadillo-legacy, so I started bisecting...
> >> >
> >> > Which board file that is?
> >> >
> >> > There is a bug that gpio_to_desc() returns NULL instead if ERR_PTR() in
> >> > that patch but I wonder why gpio_is_valid() and devm_gpio_request_one()
> >> > do not complain about that prior.
> >>
> >> arch/arm/mach-shmobile/board-armadillo800eva.c
> >
> > Are you able to put some printks() to the 'if (!template->gpiod)' branch
> > so that it prints out gpio number and what does devm_gpio_request_one()
> > return?
> >
> > Something like:
> >
> > if (!template->gpiod) {
> > ...
> > ret = devm_gpio_request_one(parent, template->gpio, flags,
> > template->name);
> > dev_info(parent, "GPIO %u, ret: %d\n", template->gpio, ret);
> > if (ret < 0)
> > ...
> >
> > led_dat->gpiod = gpio_to_desc(template->gpio);
> > dev_info(parent, "GPIOD: %p\n", led_dat->gpiod);
>
> Sure:
>
> leds-gpio leds-gpio: GPIO 102, ret: 0
> leds-gpio leds-gpio: GPIOD: c050e970
>
> So led_dat is non-NULL. But it's overwritten by NULL later:
>
> led_dat->gpiod = template->gpiod;
Ah, that's it. Nice catch!
> Whitespace damaged fix below, to fold into the original.
> If you prefer a proper separate patch, let me know.
It is up to Rafael. I think he wants to stabilize this branch so in that
case separate patch on top would work better.
Feel free to add,
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
to the patch.
>
> diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
> index ba4698c32bb04bde..b3c5d9d6a42bcd8b 100644
> --- a/drivers/leds/leds-gpio.c
> +++ b/drivers/leds/leds-gpio.c
> @@ -92,7 +92,8 @@ static int create_gpio_led(const struct gpio_led *template,
> {
> int ret, state;
>
> - if (!template->gpiod) {
> + led_dat->gpiod = template->gpiod;
> + if (!led_dat->gpiod) {
> /*
> * This is the legacy code path for platform code that
> * still uses GPIO numbers. Ultimately we would like to get
> @@ -122,8 +123,7 @@ static int create_gpio_led(const struct gpio_led *template,
>
> led_dat->cdev.name = template->name;
> led_dat->cdev.default_trigger = template->default_trigger;
> - led_dat->gpiod = template->gpiod;
> - led_dat->can_sleep = gpiod_cansleep(template->gpiod);
> + led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
> led_dat->blinking = 0;
> if (blink_set) {
> led_dat->platform_gpio_blink_set = blink_set;
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
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