[PATCH v7 30/30] drm/tests: edid: Fix conformity for 4K RGB/YUV 340MHz EDID
From: Cristian Ciocaltea
Date: Mon Jun 01 2026 - 18:53:38 EST
The test EDID added by commit 54a5f1c4d5f8 ("drm/tests: hdmi: Provide
EDID supporting 4K@30Hz with RGB/YUV") fails 'edid-decode --check'
(v1.33.0) with the following issues:
Warnings:
Block 1, CTA-861 Extension Block:
IT Video Formats are overscanned by default, but normally this should be underscanned.
YCbCr 4:2:0 Capability Map Data Block: Some YCbCr 4:2:0 timings are invalid for HDMI 2.1
(which requires an RGB timings pixel rate >= 590 MHz).
Failures:
Block 0, Base EDID:
Vendor & Product Identification: EDID 1.3 does not support week 0xff.
Detailed Timing Descriptor #1: Mismatch of image size 1600x900 mm vs display size 960x540 mm.
Block 1, CTA-861 Extension Block:
Vendor-Specific Data Block (HDMI Forum), OUI C4-5D-D8: Max TMDS rate is > 0 and <= 340 or > 600.
YCbCr 4:2:0 Video Data Block: This Data Block is empty.
Missing VCDB, needed for Set Selectable RGB Quantization to avoid interop issues.
EDID:
Base EDID: The DTD max image size is 1600x900mm, which is larger than the display size 960.0x540.0mm.
Address them while preserving the advertised maximum resolution, BPC and
TMDS clock used by the existing KUnit tests:
- Week 0xff is not valid for EDID 1.3; set it to 0x00 so that the Model
year field becomes a regular Year of Manufacture.
- Align the DTD image size with the Basic Display Parameters maximum
image size (96 cm x 54 cm).
- The HDMI Forum VSDB Max TMDS Character Rate must be 0 when no rate
above 340 MHz is supported. The HDMI VSDB still advertises 340 MHz as
Max TMDS Clock.
- Drop the empty YCbCr 4:2:0 Video Data Block. VIC 95 (3840x2160@30Hz)
remains advertised as YUV420-capable via the YCbCr 4:2:0 Capability
Map Data Block, which references the corresponding entry in the
regular Video Data Block.
- Add a Video Capability Data Block advertising selectable RGB and YCC
quantization range plus underscan for IT/CE formats; also set the 'IT
Video Formats Underscanned' bit in the CTA-861 extension header to
match.
The only remaining warning is HDMI 2.1 related and can be ignored, as it
requires that any mode listed in the YCbCr 4:2:0 Video Data Block must
have a corresponding RGB pixel clock >= 590 MHz.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
---
drivers/gpu/drm/tests/drm_kunit_edid.h | 57 ++++++++++++++++++++++------------
1 file changed, 38 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/tests/drm_kunit_edid.h b/drivers/gpu/drm/tests/drm_kunit_edid.h
index 618b42d2fd8e..9a326c9e3f7b 100644
--- a/drivers/gpu/drm/tests/drm_kunit_edid.h
+++ b/drivers/gpu/drm/tests/drm_kunit_edid.h
@@ -891,22 +891,22 @@ static const unsigned char test_edid_hdmi_1080p_rgb_yuv_4k_yuv420_dc_max_200mhz[
* edid-decode (hex):
*
* 00 ff ff ff ff ff ff 00 31 d8 34 00 00 00 00 00
- * ff 23 01 03 80 60 36 78 0f ee 91 a3 54 4c 99 26
+ * 00 23 01 03 80 60 36 78 0f ee 91 a3 54 4c 99 26
* 0f 50 54 20 00 00 01 01 01 01 01 01 01 01 01 01
* 01 01 01 01 01 01 04 74 00 30 f2 70 5a 80 b0 58
- * 8a 00 40 84 63 00 00 1e 00 00 00 fc 00 54 65 73
+ * 8a 00 c0 1c 32 00 00 1e 00 00 00 fc 00 54 65 73
* 74 20 45 44 49 44 0a 20 20 20 00 00 00 fd 00 18
* 55 18 5e 22 00 0a 20 20 20 20 20 20 00 00 00 10
- * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 ce
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 e6
*
- * 02 03 27 31 41 5f 6c 03 0c 00 10 00 78 44 20 00
- * 00 01 03 6d d8 5d c4 01 44 80 07 00 00 00 00 00
- * 00 e3 0f 01 00 e1 0e 00 00 00 00 00 00 00 00 00
+ * 02 03 28 b1 41 5f 6c 03 0c 00 10 00 78 44 20 00
+ * 00 01 03 6d d8 5d c4 01 00 80 07 00 00 00 00 00
+ * 00 e2 00 ca e3 0f 01 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 84
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 8a
*
* ----------------
*
@@ -915,7 +915,7 @@ static const unsigned char test_edid_hdmi_1080p_rgb_yuv_4k_yuv420_dc_max_200mhz[
* Vendor & Product Identification:
* Manufacturer: LNX
* Model: 52
- * Model year: 2025
+ * Made in: 2025
* Basic Display Parameters & Features:
* Digital display
* Maximum image size: 96 cm x 54 cm
@@ -933,7 +933,7 @@ static const unsigned char test_edid_hdmi_1080p_rgb_yuv_4k_yuv420_dc_max_200mhz[
* DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
* Standard Timings: none
* Detailed Timing Descriptors:
- * DTD 1: 3840x2160 30.000000 Hz 16:9 67.500 kHz 297.000000 MHz (1600 mm x 900 mm)
+ * DTD 1: 3840x2160 30.000000 Hz 16:9 67.500 kHz 297.000000 MHz (960 mm x 540 mm)
* Hfront 176 Hsync 88 Hback 296 Hpol P
* Vfront 8 Vsync 10 Vback 72 Vpol P
* Display Product Name: 'Test EDID'
@@ -941,12 +941,13 @@ static const unsigned char test_edid_hdmi_1080p_rgb_yuv_4k_yuv420_dc_max_200mhz[
* Monitor ranges (GTF): 24-85 Hz V, 24-94 kHz H, max dotclock 340 MHz
* Dummy Descriptor:
* Extension blocks: 1
- * Checksum: 0xce
+ * Checksum: 0xe6
*
* ----------------
*
* Block 1, CTA-861 Extension Block:
* Revision: 3
+ * Underscans IT Video Formats by default
* Supports YCbCr 4:4:4
* Supports YCbCr 4:2:2
* Native detailed modes: 1
@@ -962,31 +963,49 @@ static const unsigned char test_edid_hdmi_1080p_rgb_yuv_4k_yuv420_dc_max_200mhz[
* Extended HDMI video details:
* Vendor-Specific Data Block (HDMI Forum), OUI C4-5D-D8:
* Version: 1
- * Maximum TMDS Character Rate: 340 MHz
* SCDC Present
* Supports 16-bits/component Deep Color 4:2:0 Pixel Encoding
* Supports 12-bits/component Deep Color 4:2:0 Pixel Encoding
* Supports 10-bits/component Deep Color 4:2:0 Pixel Encoding
+ * VRRmin: 0 Hz
+ * VRRmax: 0 Hz
+ * Video Capability Data Block:
+ * YCbCr quantization: Selectable (via AVI YQ)
+ * RGB quantization: Selectable (via AVI Q)
+ * PT scan behavior: No Data
+ * IT scan behavior: Always Underscanned
+ * CE scan behavior: Always Underscanned
* YCbCr 4:2:0 Capability Map Data Block:
* VIC 95: 3840x2160 30.000000 Hz 16:9 67.500 kHz 297.000000 MHz
- * YCbCr 4:2:0 Video Data Block:
- * Checksum: 0x84
+ * Checksum: 0x8a Unused space in Extension Block: 87 bytes
+ *
+ * ----------------
+ *
+ * edid-decode 1.33.0
+ *
+ * Warnings:
+ *
+ * Block 1, CTA-861 Extension Block:
+ * YCbCr 4:2:0 Capability Map Data Block: Some YCbCr 4:2:0 timings are invalid for HDMI 2.1
+ * (which requires an RGB timings pixel rate >= 590 MHz).
+ *
+ * EDID conformity: PASS
*/
static const unsigned char test_edid_hdmi_4k_rgb_yuv420_dc_max_340mhz[] = {
0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x31, 0xd8, 0x34, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0xff, 0x23, 0x01, 0x03, 0x80, 0x60, 0x36, 0x78,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x23, 0x01, 0x03, 0x80, 0x60, 0x36, 0x78,
0x0f, 0xee, 0x91, 0xa3, 0x54, 0x4c, 0x99, 0x26, 0x0f, 0x50, 0x54, 0x20,
0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x04, 0x74, 0x00, 0x30, 0xf2, 0x70,
- 0x5a, 0x80, 0xb0, 0x58, 0x8a, 0x00, 0x40, 0x84, 0x63, 0x00, 0x00, 0x1e,
+ 0x5a, 0x80, 0xb0, 0x58, 0x8a, 0x00, 0xc0, 0x1c, 0x32, 0x00, 0x00, 0x1e,
0x00, 0x00, 0x00, 0xfc, 0x00, 0x54, 0x65, 0x73, 0x74, 0x20, 0x45, 0x44,
0x49, 0x44, 0x0a, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x18,
0x55, 0x18, 0x5e, 0x22, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xce, 0x02, 0x03, 0x27, 0x31,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xe6, 0x02, 0x03, 0x28, 0xb1,
0x41, 0x5f, 0x6c, 0x03, 0x0c, 0x00, 0x10, 0x00, 0x78, 0x44, 0x20, 0x00,
- 0x00, 0x01, 0x03, 0x6d, 0xd8, 0x5d, 0xc4, 0x01, 0x44, 0x80, 0x07, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0xe3, 0x0f, 0x01, 0x00, 0xe1, 0x0e, 0x00,
+ 0x00, 0x01, 0x03, 0x6d, 0xd8, 0x5d, 0xc4, 0x01, 0x00, 0x80, 0x07, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0xe2, 0x00, 0xca, 0xe3, 0x0f, 0x01, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -994,7 +1013,7 @@ static const unsigned char test_edid_hdmi_4k_rgb_yuv420_dc_max_340mhz[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x84
+ 0x00, 0x00, 0x00, 0x8a,
};
/*
--
2.54.0