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Hans de Goede authored
Another day; another DSDT bug we need to workaround...

Since commit ca876c74 ("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@vger.kernel.org
Cc: Daniel Drake <drake@endlessm.com>
Cc: Ian W MORRISON <ianwmorrison@gmail.com>
Reported-by: default avatarIan W MORRISON <ianwmorrison@gmail.com>
Suggested-by: default avatarIan W MORRISON <ianwmorrison@gmail.com>
Fixes: ca876c74 ("gpiolib-acpi: make sure we trigger edge events at least once on boot")
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20190827202835.213456-1-hdegoede@redhat.com


Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: default avatarIan W MORRISON <ianwmorrison@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
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Linux kernel
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