Re: [PATCH v5] wifi: ath9k: Obtain system GPIOS from descriptors

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Mon, Mar 16, 2026 at 09:56:58PM +0100, Linus Walleij wrote:
> The ath9k has an odd use of system-wide GPIOs: if the chip
> does not have internal GPIO capability, it will try to obtain a
> GPIO line from the system GPIO controller:
> 
>   if (BIT(gpio) & ah->caps.gpio_mask)
>         ath9k_hw_gpio_cfg_wmac(...);
>   else if (AR_SREV_SOC(ah))
>         ath9k_hw_gpio_cfg_soc(ah, gpio, out, label);
> 
> Where ath9k_hw_gpio_cfg_soc() will attempt to issue
> gpio_request_one() passing the local GPIO number of the controller
> (0..31) to gpio_request_one().
> 
> This is somewhat peculiar and possibly even dangerous: there is
> nowadays no guarantee of the numbering of these system-wide
> GPIOs, and assuming that GPIO 0..31 as used by ath9k would
> correspond to GPIOs 0..31 on the system as a whole seems a bit
> wild.
> 
> Register all 32 GPIOs at index 0..31 directly in the ATH79K
> GPIO driver and associate with the NULL device (making them
> widely available) if and only if we are probing ATH79K wifi
> from the AHB bus (used for SoCs). We obtain these offsets from
> the NULL device if necessary.
> 
> These GPIOs should ideally be defined in the device tree
> instead, but we have no control over that for the legacy
> code path.
> 
> Testcompiled with the ath79 defconfig.

...

> Changes in v5:
> - Collect Bartosz ACK
> - Switch Kalle->Jeff as maintainer.
> - Link to v4: https://lore.kernel.org/r/20260313-descriptors-wireless-v4-1-07ab47c89a98@kernel.org

Seems you forgot to address the LKP report.

> +static int ath79_gpio_register_wifi_descriptors(struct device *dev,
> +						const char *label)
> +{

Should be return SOMETHING; here.

> +}
> +#endif


-- 
With Best Regards,
Andy Shevchenko