Re: [PATCH] gpio: don't WARN() on NULL descs if gpiolib is disabled

["Claus H. Stovgaard" <cst@xxxxxxxxxxxx>]

On Mon, 2019-07-08 at 10:23 +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> 
> If gpiolib is disabled, we use the inline stubs from gpio/consumer.h
> instead of regular definitions of GPIO API. The stubs for 'optional'
> variants of gpiod_get routines return NULL in this case as if the
> relevant GPIO wasn't found. This is correct so far.
> 
> Calling other (non-gpio_get) stubs from this header triggers a
> warning
> because the GPIO descriptor couldn't have been requested. The warning
> however is unconditional (WARN_ON(1)) and is emitted even if the
> passed
> descriptor pointer is NULL.
> 
> We don't want to force the users of 'optional' gpio_get to check the
> returned pointer before calling e.g. gpiod_set_value() so let's only
> WARN on non-NULL descriptors.
> 
> Reported-by: Claus H. Stovgaard <cst@xxxxxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
>  include/linux/gpio/consumer.h | 64 +++++++++++++++++--------------
> ----
>  1 file changed, 32 insertions(+), 32 deletions(-)

Have tested it on my setup (ZynqMP with AT24 EEPROM), where it works
great. This have removed the warnings in the log regarding settting
wp_gpio for AT24.

Thanks
Claus