Re: [PATCH v2] ACPI: video: Handle fetching EDID as ACPI_TYPE_PACKAGE

[Mario Limonciello]

On 3/31/2025 08:23, Rafael J. Wysocki wrote:
> On Mon, Mar 31, 2025 at 3:04 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> > Hi,
> >
> > On 31-Mar-25 1:46 PM, Rafael J. Wysocki wrote:
> > > On Fri, Mar 28, 2025 at 10:09 PM Gergo Koteles <soyer@xxxxxx> wrote:
> > > > The _DDC method should return a buffer, or an integer in case of an error.
> > > > But some Lenovo laptops incorrectly return EDID as buffer in ACPI package.
> > > >
> > > > Calling _DDC generates this ACPI Warning:
> > > > ACPI Warning: \_SB.PCI0.GP17.VGA.LCD._DDC: Return type mismatch - \
> > > > found Package, expected Integer/Buffer (20240827/nspredef-254)
> > > >
> > > > Use the first element of the package to get the EDID buffer.
> > > >
> > > > The DSDT:
> > > >
> > > > Name (AUOP, Package (0x01)
> > > > {
> > > >          Buffer (0x80)
> > > >          {
> > > >          ...
> > > >          }
> > > > })
> > > >
> > > > ...
> > > >
> > > > Method (_DDC, 1, NotSerialized)  // _DDC: Display Data Current
> > > > {
> > > >          If ((PAID == AUID))
> > > >          {
> > > >                  Return (AUOP) /* \_SB_.PCI0.GP17.VGA_.LCD_.AUOP */
> > > >          }
> > > >          ElseIf ((PAID == IVID))
> > > >          {
> > > >                  Return (IVOP) /* \_SB_.PCI0.GP17.VGA_.LCD_.IVOP */
> > > >          }
> > > >          ElseIf ((PAID == BOID))
> > > >          {
> > > >                  Return (BOEP) /* \_SB_.PCI0.GP17.VGA_.LCD_.BOEP */
> > > >          }
> > > >          ElseIf ((PAID == SAID))
> > > >          {
> > > >                  Return (SUNG) /* \_SB_.PCI0.GP17.VGA_.LCD_.SUNG */
> > > >          }
> > > >
> > > >          Return (Zero)
> > > > }
> > > >
> > > > Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/Apx_B_Video_Extensions/output-device-specific-methods.html#ddc-return-the-edid-for-this-device
> > > > Cc: stable@xxxxxxxxxxxxxxx
> > > > Fixes: c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if available for eDP")
> > > > Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4085
> > > > Signed-off-by: Gergo Koteles <soyer@xxxxxx>
> > > > ---
> > > > Changes in v2:
> > > >   - Added comment
> > > >   - Improved commit message
> > > >   - Link to v1: https://lore.kernel.org/all/4cef341fdf7a0e877c50b502fc95ee8be28aa811.1743129387.git.soyer@xxxxxx/
> > >
> > > Hans, any concerns here?
> >
> > No the patch looks good to me:
> >
> > Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>
> OK, applied as 6.15-rc material, thanks!

Sorry I'm a bit late to the party; but this looks good to me as well. 
Thanks Gergo for the solution!

Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>