2022-08-24 13:43:25

by Henning Schild

Subject: [PATCH v2] leds: simatic-ipc-leds-gpio: make sure we have the GPIO providing driver

If we register a "leds-gpio" platform device for GPIO pins that do not
exist we get a -EPROBE_DEFER and the probe will be tried again later.
If there is not driver to provide that pin we will poll forever and also
create a lot of log messages.

So check if that GPIO driver is configured, if so it will come up
eventually. If not we exit our probe function early and do not even
bother registering the "leds-gpio". This method was chosen over "Kconfig
depends" since this way we can add support for more devices and GPIO
backends more easily without "depends"ing on all GPIO backends.

Fixes: a6c80bec3c93 ("leds: simatic-ipc-leds-gpio: Add GPIO version of Siemens driver")
Signed-off-by: Henning Schild <[email protected]>
---
drivers/leds/simple/simatic-ipc-leds-gpio.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/leds/simple/simatic-ipc-leds-gpio.c b/drivers/leds/simple/simatic-ipc-leds-gpio.c
index 4c9e663a90ba..0c96ba98e338 100644
--- a/drivers/leds/simple/simatic-ipc-leds-gpio.c
+++ b/drivers/leds/simple/simatic-ipc-leds-gpio.c
@@ -57,6 +57,8 @@ static int simatic_ipc_leds_gpio_probe(struct platform_device *pdev)
struct gpio_desc *gpiod;
int err;

+ if (!IS_ENABLED(CONFIG_PINCTRL_BROXTON))
+ return -ENODEV;
gpiod_add_lookup_table(&simatic_ipc_led_gpio_table);
simatic_leds_pdev = platform_device_register_resndata(NULL,
"leds-gpio", PLATFORM_DEVID_NONE, NULL, 0,
--
2.35.1

2022-08-24 16:10:23

by Andy Shevchenko

Subject: Re: [PATCH v2] leds: simatic-ipc-leds-gpio: make sure we have the GPIO providing driver

On Wed, Aug 24, 2022 at 4:27 PM Henning Schild
<[email protected]> wrote:
>
> If we register a "leds-gpio" platform device for GPIO pins that do not
> exist we get a -EPROBE_DEFER and the probe will be tried again later.
> If there is not driver to provide that pin we will poll forever and also

not --> no

> create a lot of log messages.
>
> So check if that GPIO driver is configured, if so it will come up
> eventually. If not we exit our probe function early and do not even

not, we

> bother registering the "leds-gpio". This method was chosen over "Kconfig
> depends" since this way we can add support for more devices and GPIO
> backends more easily without "depends"ing on all GPIO backends.

"depends":ing

The code is fine from my perspective,
Reviewed-by: Andy Shevchenko <[email protected]>
thanks!

> Fixes: a6c80bec3c93 ("leds: simatic-ipc-leds-gpio: Add GPIO version of Siemens driver")
> Signed-off-by: Henning Schild <[email protected]>
> ---
> drivers/leds/simple/simatic-ipc-leds-gpio.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/leds/simple/simatic-ipc-leds-gpio.c b/drivers/leds/simple/simatic-ipc-leds-gpio.c
> index 4c9e663a90ba..0c96ba98e338 100644
> --- a/drivers/leds/simple/simatic-ipc-leds-gpio.c
> +++ b/drivers/leds/simple/simatic-ipc-leds-gpio.c
> @@ -57,6 +57,8 @@ static int simatic_ipc_leds_gpio_probe(struct platform_device *pdev)
> struct gpio_desc *gpiod;
> int err;
>
> + if (!IS_ENABLED(CONFIG_PINCTRL_BROXTON))
> + return -ENODEV;
> gpiod_add_lookup_table(&simatic_ipc_led_gpio_table);
> simatic_leds_pdev = platform_device_register_resndata(NULL,
> "leds-gpio", PLATFORM_DEVID_NONE, NULL, 0,
> --
> 2.35.1
>


--
With Best Regards,
Andy Shevchenko

2022-08-25 08:22:46

by Henning Schild

Subject: Re: [PATCH v2] leds: simatic-ipc-leds-gpio: make sure we have the GPIO providing driver

Am Wed, 24 Aug 2022 18:53:49 +0300
schrieb Andy Shevchenko <[email protected]>:

> On Wed, Aug 24, 2022 at 4:27 PM Henning Schild
> <[email protected]> wrote:
> >
> > If we register a "leds-gpio" platform device for GPIO pins that do
> > not exist we get a -EPROBE_DEFER and the probe will be tried again
> > later. If there is not driver to provide that pin we will poll
> > forever and also
>
> not --> no
>
> > create a lot of log messages.
> >
> > So check if that GPIO driver is configured, if so it will come up
> > eventually. If not we exit our probe function early and do not even
> >
>
> not, we
>
> > bother registering the "leds-gpio". This method was chosen over
> > "Kconfig depends" since this way we can add support for more
> > devices and GPIO backends more easily without "depends"ing on all
> > GPIO backends.
>
> "depends":ing
>
> The code is fine from my perspective,
> Reviewed-by: Andy Shevchenko <[email protected]>
> thanks!

Thank you! Typos fixed and tag added in v3.

Henning

>
> > Fixes: a6c80bec3c93 ("leds: simatic-ipc-leds-gpio: Add GPIO version
> > of Siemens driver") Signed-off-by: Henning Schild
> > <[email protected]> ---
> > drivers/leds/simple/simatic-ipc-leds-gpio.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/leds/simple/simatic-ipc-leds-gpio.c
> > b/drivers/leds/simple/simatic-ipc-leds-gpio.c index
> > 4c9e663a90ba..0c96ba98e338 100644 ---
> > a/drivers/leds/simple/simatic-ipc-leds-gpio.c +++
> > b/drivers/leds/simple/simatic-ipc-leds-gpio.c @@ -57,6 +57,8 @@
> > static int simatic_ipc_leds_gpio_probe(struct platform_device
> > *pdev) struct gpio_desc *gpiod; int err;
> >
> > + if (!IS_ENABLED(CONFIG_PINCTRL_BROXTON))
> > + return -ENODEV;
> > gpiod_add_lookup_table(&simatic_ipc_led_gpio_table);
> > simatic_leds_pdev = platform_device_register_resndata(NULL,
> > "leds-gpio", PLATFORM_DEVID_NONE, NULL, 0,
> > --
> > 2.35.1
> >
>
>