Hi Mika,

On Thu, Nov 6, 2014 at 11:58 AM, Mika Westerberg
[off-list ref] wrote:

On Thu, Nov 06, 2014 at 11:32:19AM +0100, Geert Uytterhoeven wrote:

quoted

On Thu, Nov 6, 2014 at 11:30 AM, Mika Westerberg
[off-list ref] wrote:

quoted

quoted

"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;

Whitespace damaged fix below, to fold into the original.
If you prefer a proper separate patch, let me know.

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 at linux-m68k.org

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