ACPI Warning: \_SB.PCI0.GP17.VGA.LCD._DDC: Return type mismatch - found Package, expected Integer/Buffer (20240827/nspredef-254)

I get this warning since 6.13.

My Lenovo 14ARB7 returns EDID as a buffer in ACPI package. I wrote a patch that handles the package. Since then it seems like the screen hasn't even flickered, but it is not certain that this is the reason.

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)
}

old EDID:

edid-decode (hex):

00 ff ff ff ff ff ff 00 4c 83 7a 41 00 00 00 00
23 1e 01 04 b5 1e 13 78 02 0c f1 ae 52 3c b9 23
0c 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01
01 01 01 01 01 01 a4 c3 40 50 b0 08 50 70 08 20
88 00 2e bd 10 00 00 1b a4 c3 40 50 b0 08 fc 73
08 20 88 00 2e bd 10 00 00 1b 00 00 00 0f 00 ff
0a 5a ff 0a 3c 28 80 00 00 00 00 00 00 00 00 fe
00 41 54 4e 41 34 30 59 4b 30 38 2d 30 20 01 79

02 03 0f 00 e3 05 80 00 e6 06 05 01 74 60 07 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b7

----------------

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.4
  Vendor & Product Identification:
    Manufacturer: SDC
    Model: 16762
    Made in: week 35 of 2020
  Basic Display Parameters & Features:
    Digital display
    Bits per primary color channel: 10
    DisplayPort interface
    Maximum image size: 30 cm x 19 cm
    Gamma: 2.20
    Supported color formats: RGB 4:4:4
    First detailed timing includes the native pixel format and preferred refresh rate
  Color Characteristics:
    Red  : 0.6796, 0.3203
    Green: 0.2373, 0.7226
    Blue : 0.1396, 0.0498
    White: 0.3125, 0.3291
  Established Timings I & II: none
  Standard Timings: none
  Detailed Timing Descriptors:
    DTD 1:  2880x1800   90.001438 Hz  16:10   169.203 kHz    500.840000 MHz (302 mm x 189 mm)
                 Hfront    8 Hsync  32 Hback   40 Hpol P
                 Vfront    8 Vsync   8 Vback   64 Vpol N
    DTD 2:  2880x1800   60.000958 Hz  16:10   169.203 kHz    500.840000 MHz (302 mm x 189 mm)
                 Hfront    8 Hsync  32 Hback   40 Hpol P
                 Vfront    8 Vsync   8 Vback 1004 Vpol N
    Manufacturer-Specified Display Descriptor (0x0f): 00 0f 00 ff 0a 5a ff 0a 3c 28 80 00 00 00 00 00 '.....Z..<(......'
    Alphanumeric Data String: 'ATNA40YK08-0 '
  Extension blocks: 1
Checksum: 0x79

----------------

Block 1, CTA-861 Extension Block:
  Revision: 3
  Native detailed modes: 0
  Colorimetry Data Block:
    BT2020RGB
  HDR Static Metadata Data Block:
    Electro optical transfer functions:
      Traditional gamma - SDR luminance range
      SMPTE ST2084
    Supported static metadata descriptors:
      Static metadata type 1
    Desired content max luminance: 116 (616.884 cd/m^2)
    Desired content max frame-average luminance: 96 (400.000 cd/m^2)
    Desired content min luminance: 7 (0.005 cd/m^2)
Checksum: 0xb7  Unused space in Extension Block: 112 bytes

new EDID:

edid-decode (hex):

00 ff ff ff ff ff ff 00 30 ae 98 8a 00 00 00 00
23 1e 01 04 b5 1e 13 78 02 0c f1 ae 52 3c b9 23
0c 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01
01 01 01 01 01 01 a4 c3 40 50 b0 08 fc 73 08 20
88 00 2e bd 10 00 00 1b a4 c3 40 50 b0 08 50 70
08 20 88 00 2e bd 10 00 00 1b 00 00 00 fe 00 4c
45 4e 4f 56 4f 0a 20 20 20 20 20 20 00 00 00 fe
00 4c 45 4e 31 34 30 57 51 2b 0a 20 20 20 01 27

02 03 0f 00 e3 05 80 00 e6 06 05 01 74 60 07 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b7

----------------

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.4
  Vendor & Product Identification:
    Manufacturer: LEN
    Model: 35480
    Made in: week 35 of 2020
  Basic Display Parameters & Features:
    Digital display
    Bits per primary color channel: 10
    DisplayPort interface
    Maximum image size: 30 cm x 19 cm
    Gamma: 2.20
    Supported color formats: RGB 4:4:4
    First detailed timing includes the native pixel format and preferred refresh rate
  Color Characteristics:
    Red  : 0.6796, 0.3203
    Green: 0.2373, 0.7226
    Blue : 0.1396, 0.0498
    White: 0.3125, 0.3291
  Established Timings I & II: none
  Standard Timings: none
  Detailed Timing Descriptors:
    DTD 1:  2880x1800   60.000958 Hz  16:10   169.203 kHz    500.840000 MHz (302 mm x 189 mm)
                 Hfront    8 Hsync  32 Hback   40 Hpol P
                 Vfront    8 Vsync   8 Vback 1004 Vpol N
    DTD 2:  2880x1800   90.001438 Hz  16:10   169.203 kHz    500.840000 MHz (302 mm x 189 mm)
                 Hfront    8 Hsync  32 Hback   40 Hpol P
                 Vfront    8 Vsync   8 Vback   64 Vpol N
    Alphanumeric Data String: 'LENOVO'
    Alphanumeric Data String: 'LEN140WQ+'
  Extension blocks: 1
Checksum: 0x27

----------------

Block 1, CTA-861 Extension Block:
  Revision: 3
  Native detailed modes: 0
  Colorimetry Data Block:
    BT2020RGB
  HDR Static Metadata Data Block:
    Electro optical transfer functions:
      Traditional gamma - SDR luminance range
      SMPTE ST2084
    Supported static metadata descriptors:
      Static metadata type 1
    Desired content max luminance: 116 (616.884 cd/m^2)
    Desired content max frame-average luminance: 96 (400.000 cd/m^2)
    Desired content min luminance: 7 (0.005 cd/m^2)
Checksum: 0xb7  Unused space in Extension Block: 112 bytes

0001-ACPI-video-Handle-fetching-EDID-as-ACPI_TYPE_PACKAGE.patch

I don't know if this should be handled in the kernel, or reported to Lenovo, or both.

changed the description

I don't know if this should be handled in the kernel, or reported to Lenovo, or both.

Thanks for coming up with the patch! I would say do both. You can send that patch to the M/L after the merge window is done. Don't forget to add a tag for:

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4085

Loop @mpearson

added Rembrandt bisected labels

If I apply this patch on the top of "Merge tag 'drm-next-2025-03-28' of https://gitlab.freedesktop.org/drm/kernel" (0c86b42439b6c11d758b3392a21117934fef00c), only the 90Hz display refresh rate is available. If I apply it on previous commits, both 60Hz and 90Hz are available.

mentioned in commit nouveau@ebca08fe