Re: [PATCH v2] gpiolib: acpi: Add gpiolib_acpi_run_edge_events_on_boot option and blacklist

From: Ian W MORRISON <ianwmorrison@gmail.com>
To: Hans de Goede <hdegoede@redhat.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-gpio@vger.kernel.org, linux-acpi@vger.kernel.org,
	stable@vger.kernel.org, Daniel Drake <drake@endlessm.com>
Subject: Re: [PATCH v2] gpiolib: acpi: Add gpiolib_acpi_run_edge_events_on_boot option and blacklist
Date: Wed, 28 Aug 2019 23:16:42 +1000	[thread overview]
Message-ID: <CAFXWsS89-fB=LGLRpeSrH8Y97=fqhZ7d77WORjXdS1YU5Xbfsg@mail.gmail.com> (raw)
In-Reply-To: <c07a8e2e-61a7-7ce7-4f73-48978be98d27@redhat.com>

On Wed, 28 Aug 2019 at 22:21, Hans de Goede <hdegoede@redhat.com> wrote:
>
> Hi,
>
> On 28-08-19 14:20, Hans de Goede wrote:
> > Hi,
> >
> > On 28-08-19 13:37, Andy Shevchenko wrote:
> >> On Tue, Aug 27, 2019 at 10:28:35PM +0200, Hans de Goede wrote:
> >>> Another day; another DSDT bug we need to workaround...
> >>>
> >>> Since commit ca876c7483b6 ("gpiolib-acpi: make sure we trigger edge events
> >>> at least once on boot") we call _AEI edge handlers at boot.
> >>>
> >>> In some rare cases this causes problems. One example of this is the Minix
> >>> Neo Z83-4 mini PC, this device has a clear DSDT bug where it has some copy
> >>> and pasted code for dealing with Micro USB-B connector host/device role
> >>> switching, while the mini PC does not even have a micro-USB connector.
> >>> This code, which should not be there, messes with the DDC data pin from
> >>> the HDMI connector (switching it to GPIO mode) breaking HDMI support.
> >>>
> >>> To avoid problems like this, this commit adds a new
> >>> gpiolib_acpi.run_edge_events_on_boot kernel commandline option, which
> >>> allows disabling the running of _AEI edge event handlers at boot.
> >>>
> >>> The default value is -1/auto which uses a DMI based blacklist, the initial
> >>> version of this blacklist contains the Neo Z83-4 fixing the HDMI breakage.
> >>
> >> Thank you!
> >>
> >> Assuming it works for Ian,
> >> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> >
> > Note I have access to a Minix Neo Z83-4 myself now and I did test that
> > this fixes it and that passing gpiolib_acpi.run_edge_events_on_boot=0
> > breaks HDMI again (so the option works).
>
> Erm that should be gpiolib_acpi.run_edge_events_on_boot=1 (not 0) breaks
> HDMI.
>

Many thanks again Hans. I've also tested the patch including the various command
line options on my MINIX Z83-4 and they work fine.

Best regards,
Ian