On 3/31/2025 08:23, Rafael J. Wysocki wrote:
On Mon, Mar 31, 2025 at 3:04 PM Hans de Goede <hdego...@redhat.com> wrote:
Hi,
On 31-Mar-25 1:46 PM, Rafael J. Wysocki wrote:
On Fri, Mar 28, 2025 at 10:09 PM Gergo Koteles <so...@irl.hu> 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: sta...@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 <so...@irl.hu>
---
Changes in v2:
- Added comment
- Improved commit message
- Link to v1:
https://lore.kernel.org/all/4cef341fdf7a0e877c50b502fc95ee8be28aa811.1743129387.git.so...@irl.hu/
Hans, any concerns here?
No the patch looks good to me:
Reviewed-by: Hans de Goede <hdego...@redhat.com>
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.limoncie...@amd.com>
