Re: [PATCH] pinctrl: amd: Clear GPIO debounce for suspend

[Hans de Goede <hansg@kernel.org>]

Hi Mario,

On 27-Jun-25 12:14 AM, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> soc-button-array hardcodes a debounce value by means of gpio_keys
> which uses pinctrl-amd as a backend to program debounce for a GPIO.
> 
> This hardcoded value doesn't match what the firmware intended to be
> programmed in _AEI. The hardcoded debounce leads to problems waking
> from suspend. There isn't appetite to conditionalize the behavior in
> soc-button-array or gpio-keys so clear it when the system suspends to
> avoid problems with being able to resume.

Nice I do think this is a better solution then disabling hw-debounce
in soc-button-array as we did before.

> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: Hans de Goede <hansg@kernel.org>
> Fixes: 5c4fa2a6da7fb ("Input: soc_button_array - debounce the buttons")
> Link: https://lore.kernel.org/linux-input/mkgtrb5gt7miyg6kvqdlbu4nj3elym6ijudobpdi26gp4xxay5@rsa6ytrjvj2q/
> Link: https://lore.kernel.org/linux-input/20250625215813.3477840-1-superm1@kernel.org/
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/pinctrl/pinctrl-amd.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
> index 5cf3db6d78b79..4276bbe77e0e9 100644
> --- a/drivers/pinctrl/pinctrl-amd.c
> +++ b/drivers/pinctrl/pinctrl-amd.c
> @@ -979,6 +979,13 @@ static int amd_gpio_suspend_hibernate_common(struct device *dev, bool is_suspend
>  				  pin, is_suspend ? "suspend" : "hibernate");
>  		}
>  
> +		/* clear debounce */
> +		if (gpio_dev->saved_regs[i] & (DB_CNTRl_MASK << DB_CNTRL_OFF)) {
> +			amd_gpio_set_debounce(gpio_dev, pin, 0);
> +			pm_pr_dbg("Clearing debounce for GPIO #%d during %s.\n",
> +				  pin, is_suspend ? "suspend" : "hibernate");
> +		}
> +


I notice that the if () { } block above this checks if a pin is not configured
to be a wakeup src. Since we only need this for wakeup sources maybe put this
in an else block of the if () { } block above this ?

I've not strong preference for doing this change, just something which I noticed
while looking at the code.

Either way this should probably have a comment on why the clearing is done here.

Regards,

Hans



>  		raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
>  	}
>