RE: [PATCH] nvidia-wmi-ec-backlight: Add workarounds for confused firmware

["Limonciello, Mario" <Mario.Limonciello@amd.com>]

[Public]



> -----Original Message-----
> From: Daniel Dadap <ddadap@nvidia.com>
> Sent: Wednesday, March 16, 2022 14:24
> To: Limonciello, Mario <Mario.Limonciello@amd.com>; Barnabás Pőcze
> <pobrn@protonmail.com>
> Cc: platform-driver-x86@vger.kernel.org; Alexandru Dinu
> <alex.dinu07@gmail.com>; Hans de Goede <hdegoede@redhat.com>;
> markgross@kernel.org; Deucher, Alexander
> <Alexander.Deucher@amd.com>
> Subject: Re: [PATCH] nvidia-wmi-ec-backlight: Add workarounds for
> confused firmware
> 
> On 3/16/22 13:25, Limonciello, Mario wrote:
> > [Public]
> >
> >
> > I guess when we see backlight issues on these A+N designs the checks
> should be:
> > 1) Are they supposed to be using the nvidia-wmi-ec-backlight driver?
> > 2) Is their kernel new enough to have it?
> > 3) Do they have the config enabled?
> >
> > Do you have a script or could you perhaps include some documentation we
> can
> > point people to check "1" so we don't always have to go tear apart ACPI
> tables
> > and make guesses?
> >
> > I guess it's something like grab _WDG and then parse it to see if there is an
> entry.
> 
> 
> Probably the most foolproof way would be to check for the GUID
> 603E9613-EF25-4338-A3D0-C46177516DB7 in /sys/bus/wmi/devices. (2)
> should
> be true for vanilla 5.16 and later, and many recent pre-5.16 distro
> kernels with HWE backports.

Perfect, thanks!