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.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Daniel Drake <drake@xxxxxxxxxxxx>
> Cc: Ian W MORRISON <ianwmorrison@xxxxxxxxx>
> Reported-by: Ian W MORRISON <ianwmorrison@xxxxxxxxx>
> Suggested-by: Ian W MORRISON <ianwmorrison@xxxxxxxxx>
> Fixes: ca876c7483b6 ("gpiolib-acpi: make sure we trigger edge events at least once on boot")
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
