Re: [PATCH 6.17 REGRESSION FIX] gpiolib: acpi: Make set debounce errors non fatal

["Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>]

On 9/20/2025 3:12 PM, Hans de Goede wrote:
> Commit 16c07342b542 ("gpiolib: acpi: Program debounce when finding GPIO")
> adds a gpio_set_debounce_timeout() call to acpi_find_gpio() and makes
> acpi_find_gpio() fail if this fails.
> 
> But gpio_set_debounce_timeout() failing is a somewhat normal occurrence,
> since not all debounce values are supported on all GPIO/pinctrl chips.
> 
> Making this an error for example break getting the card-detect GPIO for
> the micro-sd slot found on many Bay Trail tablets, breaking support for
> the micro-sd slot on these tablets.
> 
> acpi_request_own_gpiod() already treats gpio_set_debounce_timeout()
> failures as non-fatal, just warning about them.
> 
> Add a acpi_gpio_set_debounce_timeout() helper which wraps
> gpio_set_debounce_timeout() and warns on failures and replace both existing
> gpio_set_debounce_timeout() calls with the helper.
> 
> Since the helper only warns on failures this fixes the card-detect issue.
> 
> Fixes: 16c07342b542 ("gpiolib: acpi: Program debounce when finding GPIO")
> Cc: stable@vger.kernel.org
> Cc: Mario Limonciello <superm1@kernel.org>
> Signed-off-by: Hans de Goede <hansg@kernel.org>

Looks pretty much identical now to what I sent in my v3 and that Andy 
had requested we change to make it fatal [1].

Where is this bad GPIO value coming from?  It's in the GpioInt() 
declaration?  If so, should the driver actually be supporting this?

https://lore.kernel.org/linux-gpio/20250811164356.613840-1-superm1@kernel.org/ 
[1]

> ---
>   drivers/gpio/gpiolib-acpi-core.c | 27 +++++++++++++++------------
>   1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib-acpi-core.c b/drivers/gpio/gpiolib-acpi-core.c
> index 284e762d92c4..67c4c38afb86 100644
> --- a/drivers/gpio/gpiolib-acpi-core.c
> +++ b/drivers/gpio/gpiolib-acpi-core.c
> @@ -291,6 +291,19 @@ acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio, int polarity)
>   	return GPIOD_ASIS;
>   }
>   
> +static void acpi_gpio_set_debounce_timeout(struct gpio_desc *desc,
> +					   unsigned int acpi_debounce)
> +{
> +	int ret;
> +
> +	/* ACPI uses hundredths of milliseconds units */
> +	acpi_debounce *= 10;
> +	ret = gpio_set_debounce_timeout(desc, acpi_debounce);
> +	if (ret)
> +		gpiod_warn(desc, "Failed to set debounce-timeout %u: %d\n",
> +			   acpi_debounce, ret);
> +}
> +
>   static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip,
>   						struct acpi_resource_gpio *agpio,
>   						unsigned int index,
> @@ -300,18 +313,12 @@ static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip,
>   	enum gpiod_flags flags = acpi_gpio_to_gpiod_flags(agpio, polarity);
>   	unsigned int pin = agpio->pin_table[index];
>   	struct gpio_desc *desc;
> -	int ret;
>   
>   	desc = gpiochip_request_own_desc(chip, pin, label, polarity, flags);
>   	if (IS_ERR(desc))
>   		return desc;
>   
> -	/* ACPI uses hundredths of milliseconds units */
> -	ret = gpio_set_debounce_timeout(desc, agpio->debounce_timeout * 10);
> -	if (ret)
> -		dev_warn(chip->parent,
> -			 "Failed to set debounce-timeout for pin 0x%04X, err %d\n",
> -			 pin, ret);
> +	acpi_gpio_set_debounce_timeout(desc, agpio->debounce_timeout);
>   
>   	return desc;
>   }
> @@ -944,7 +951,6 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
>   	bool can_fallback = acpi_can_fallback_to_crs(adev, con_id);
>   	struct acpi_gpio_info info = {};
>   	struct gpio_desc *desc;
> -	int ret;
>   
>   	desc = __acpi_find_gpio(fwnode, con_id, idx, can_fallback, &info);
>   	if (IS_ERR(desc))
> @@ -959,10 +965,7 @@ struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
>   	acpi_gpio_update_gpiod_flags(dflags, &info);
>   	acpi_gpio_update_gpiod_lookup_flags(lookupflags, &info);
>   
> -	/* ACPI uses hundredths of milliseconds units */
> -	ret = gpio_set_debounce_timeout(desc, info.debounce * 10);
> -	if (ret)
> -		return ERR_PTR(ret);
> +	acpi_gpio_set_debounce_timeout(desc, info.debounce);
>   
>   	return desc;
>   }