Re: [PATCH] gpiolib: enable CONFIG_GPIOLIB_LEGACY even for !GPIOLIB

[Rob Herring <robh@kernel.org>]

On Sat, Jul 26, 2025 at 11:10:43PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> A few drivers that use the legacy GPIOLIB interfaces can be enabled
> even when GPIOLIB is disabled entirely. With my previous patch this
> now causes build failures like:
> 
>    drivers/nfc/s3fwrn5/uart.c: In function 's3fwrn82_uart_parse_dt':
>         drivers/nfc/s3fwrn5/uart.c:100:14: error: implicit declaration of function 'gpio_is_valid'; did you mean 'uuid_is_valid'? [-Werror=implicit-function-declaration]
> 
> These did not show up in my randconfig tests because randconfig almost
> always has GPIOLIB selected by some other driver, and I did most
> of the testing with follow-up patches that address the failures
> properly.
> 
> Move the symbol outside of the 'if CONFIG_GPIOLIB' block for the moment
> to avoid the build failures. It can be moved back and turned off by
> default once all the driver specific changes are merged.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202507261934.yIHeUuEQ-lkp@intel.com/
> Fixes: 678bae2eaa81 ("gpiolib: make legacy interfaces optional")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/gpio/Kconfig | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

This change causes all of the GPIO submenu to show up directly in the 
already way too long 'Device Drivers' menu.

> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 8bda3c9d47b4..c48f9badb513 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -12,11 +12,11 @@ menuconfig GPIOLIB
>  
>  	  If unsure, say N.
>  
> -if GPIOLIB
> -
>  config GPIOLIB_LEGACY
>  	def_bool y

Perhaps this has to be before "menuconfig GPIOLIB"?

>  
> +if GPIOLIB
> +
>  config GPIOLIB_FASTPATH_LIMIT
>  	int "Maximum number of GPIOs for fast path"
>  	range 32 512
> -- 
> 2.39.5
>