ACPI: video: Handle fetching EDID as ACPI_TYPE_PACKAGE

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@vger.kernel.org
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@irl.hu>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/61c3df83ab73aba0bc7a941a443cd7faf4cf7fb0.1743195250.git.soyer@irl.hu
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

0 files changed, 0 insertions, 0 deletions