Re: [PATCH regression fix] gpiolib: acpi: Make set-debounce-timeout failures non fatal

From: Hans de Goede <hdegoede@redhat.com>
To: Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	ACPI Devel Maling List <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH regression fix] gpiolib: acpi: Make set-debounce-timeout failures non fatal
Date: Tue, 21 Sep 2021 20:42:43 +0200	[thread overview]
Message-ID: <86fafc6f-113c-2ea9-579b-ea29343865da@redhat.com> (raw)
In-Reply-To: <CACRpkdZ8ngakZhbrJp=OjcayLJ4j7C9gqb72N18fHExtMT7gNg@mail.gmail.com>

Hi,

On 9/21/21 8:28 PM, Linus Walleij wrote:
> On Mon, Aug 16, 2021 at 11:39 AM Hans de Goede <hdegoede@redhat.com> wrote:
> 
>> Commit 8dcb7a15a585 ("gpiolib: acpi: Take into account debounce settings")
>> made the gpiolib-acpi code call gpio_set_debounce_timeout() when requesting
>> GPIOs.
>>
>> This in itself is fine, but it also made gpio_set_debounce_timeout()
>> errors fatal, causing the requesting of the GPIO to fail. This is causing
>> regressions. E.g. on a HP ElitePad 1000 G2 various _AEI specified GPIO
>> ACPI event sources specify a debouncy timeout of 20 ms, but the
>> pinctrl-baytrail.c only supports certain fixed values, the closest
>> ones being 12 or 14 ms and pinctrl-baytrail.c responds with -EINVAL
>> when specified a value which is not one of the fixed values.
>>
>> This is causing the acpi_request_own_gpiod() call to fail for 3
>> ACPI event sources on the HP ElitePad 1000 G2, which in turn is causing
>> e.g. the battery charging vs discharging status to never get updated,
>> even though a charger has been plugged-in or unplugged.
>>
>> Make gpio_set_debounce_timeout() errors non fatal, warning about the
>> failure instead, to fix this regression.
>>
>> Note we should probably also fix various pinctrl drivers to just
>> pick the first bigger discrete value rather then returning -EINVAL but
>> this will need to be done on a per driver basis, where as this fix
>> at least gets us back to where things were before and thus restores
>> functionality on devices where this was lost due to
>> gpio_set_debounce_timeout() errors.
>>
>> Fixes: 8dcb7a15a585 ("gpiolib: acpi: Take into account debounce settings")
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> Bartosz will pick this up I think, I'm a bit off duty with GPIO right now.

Added Bartosz to the To: list, to make sure that he actually
sees this. I somehow did not add him in the To/Cc when sending out
the patch, sorry about that.

Regards,

Hans