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#1 Yesterday 22:04:00

FineWolf
Member
Registered: 2026-03-23
Posts: 2

[AMDGPU] 4:2:0 output via HDMI seems broken since kernel 7.2

I have a mini-PC that I use as a Smart TV box. Since kernel 7.2, I can no longer get an output at any resolution where my TV expects a `7:2:0` signal.

edid-decode (hex):

00 ff ff ff ff ff ff 00 4c 2d 42 0d 00 00 00 01
01 1a 01 03 80 8e 50 78 0a 23 ad a4 54 4d 99 26
0f 47 4a bd ef 80 71 4f 81 c0 81 00 81 80 95 00
a9 c0 b3 00 01 01 04 74 00 30 f2 70 5a 80 b0 58
8a 00 50 1d 74 00 00 1e 02 3a 80 18 71 38 2d 40
58 2c 45 00 50 1d 74 00 00 1e 00 00 00 fd 00 18
4b 0f 51 1e 00 0a 20 20 20 20 20 20 00 00 00 fc
00 53 41 4d 53 55 4e 47 0a 20 20 20 20 20 01 d4

02 03 46 f0 53 5f 10 1f 04 13 05 14 20 21 22 5d
5e 62 63 64 07 16 03 12 29 09 07 07 15 07 50 3d
04 c0 83 01 00 00 e2 00 0f e3 05 03 01 6e 03 0c
00 22 00 b8 3c 20 00 80 01 02 03 04 e3 06 0d 01
e5 0e 60 61 65 66 01 1d 80 d0 72 1c 16 20 10 2c
25 80 50 1d 74 00 00 9e 66 21 56 aa 51 00 1e 30
46 8f 33 00 50 1d 74 00 00 1e 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 bb

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

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.3
  Vendor & Product Identification:
    Manufacturer: SAM
    Model: 3394
    Serial Number: 16777216 (0x01000000)
    Made in: week 1 of 2016
  Basic Display Parameters & Features:
    Digital display
    Maximum image size: 142 cm x 80 cm
    Gamma: 2.20
    RGB color display
    First detailed timing is the preferred timing
  Color Characteristics:
    Red  : 0.6406, 0.3300
    Green: 0.3007, 0.6005
    Blue : 0.1503, 0.0605
    White: 0.2802, 0.2900
  Established Timings I & II:
    IBM     :   720x400    70.081663 Hz   9:5     31.467 kHz     28.320000 MHz
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    Apple   :   640x480    66.666667 Hz   4:3     35.000 kHz     30.240000 MHz
    DMT 0x05:   640x480    72.808802 Hz   4:3     37.861 kHz     31.500000 MHz
    DMT 0x06:   640x480    75.000000 Hz   4:3     37.500 kHz     31.500000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x0a:   800x600    72.187572 Hz   4:3     48.077 kHz     50.000000 MHz
    DMT 0x0b:   800x600    75.000000 Hz   4:3     46.875 kHz     49.500000 MHz
    Apple   :   832x624    74.551266 Hz   4:3     49.726 kHz     57.284000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
    DMT 0x11:  1024x768    70.069359 Hz   4:3     56.476 kHz     75.000000 MHz
    DMT 0x12:  1024x768    75.028582 Hz   4:3     60.023 kHz     78.750000 MHz
    DMT 0x24:  1280x1024   75.024675 Hz   5:4     79.976 kHz    135.000000 MHz
    Apple   :  1152x870    75.061550 Hz 192:145   68.681 kHz    100.000000 MHz
  Standard Timings:
    DMT 0x15:  1152x864    75.000000 Hz   4:3     67.500 kHz    108.000000 MHz
    DMT 0x55:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    DMT 0x1c:  1280x800    59.810326 Hz  16:10    49.702 kHz     83.500000 MHz
    DMT 0x23:  1280x1024   60.019740 Hz   5:4     63.981 kHz    108.000000 MHz
    DMT 0x2f:  1440x900    59.887445 Hz  16:10    55.935 kHz    106.500000 MHz
    DMT 0x53:  1600x900    60.000000 Hz  16:9     60.000 kHz    108.000000 MHz (RB)
    DMT 0x3a:  1680x1050   59.954250 Hz  16:10    65.290 kHz    146.250000 MHz
  Detailed Timing Descriptors:
    DTD 1:  3840x2160   30.000000 Hz  16:9     67.500 kHz    297.000000 MHz (1872 mm x 1053 mm)
                 Hfront  176 Hsync  88 Hback  296 Hpol P
                 Vfront    8 Vsync  10 Vback   72 Vpol P
    DTD 2:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (1872 mm x 1053 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P
    Display Range Limits:
      Monitor ranges (GTF): 24-75 Hz V, 15-81 kHz H, max dotclock 300 MHz
    Display Product Name: 'SAMSUNG'
  Extension blocks: 1
Checksum: 0xd4

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

Block 1, CTA-861 Extension Block:
  Revision: 3
  Underscans IT Video Formats by default
  Basic audio support
  Supports YCbCr 4:4:4
  Supports YCbCr 4:2:2
  Native detailed modes: 0
  Video Data Block:
    VIC  95:  3840x2160   30.000000 Hz  16:9     67.500 kHz    297.000000 MHz
    VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz
    VIC  31:  1920x1080   50.000000 Hz  16:9     56.250 kHz    148.500000 MHz
    VIC   4:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    VIC  19:  1280x720    50.000000 Hz  16:9     37.500 kHz     74.250000 MHz
    VIC   5:  1920x1080i  60.000000 Hz  16:9     33.750 kHz     74.250000 MHz
    VIC  20:  1920x1080i  50.000000 Hz  16:9     28.125 kHz     74.250000 MHz
    VIC  32:  1920x1080   24.000000 Hz  16:9     27.000 kHz     74.250000 MHz
    VIC  33:  1920x1080   25.000000 Hz  16:9     28.125 kHz     74.250000 MHz
    VIC  34:  1920x1080   30.000000 Hz  16:9     33.750 kHz     74.250000 MHz
    VIC  93:  3840x2160   24.000000 Hz  16:9     54.000 kHz    297.000000 MHz
    VIC  94:  3840x2160   25.000000 Hz  16:9     56.250 kHz    297.000000 MHz
    VIC  98:  4096x2160   24.000000 Hz 256:135   54.000 kHz    297.000000 MHz
    VIC  99:  4096x2160   25.000000 Hz 256:135   56.250 kHz    297.000000 MHz
    VIC 100:  4096x2160   30.000000 Hz 256:135   67.500 kHz    297.000000 MHz
    VIC   7:  1440x480i   59.940060 Hz  16:9     15.734 kHz     27.000000 MHz
    VIC  22:  1440x576i   50.000000 Hz  16:9     15.625 kHz     27.000000 MHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz     27.000000 MHz
    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz     27.000000 MHz
  Audio Data Block:
    Linear PCM:
      Max channels: 2
      Supported sample rates (kHz): 48 44.1 32
      Supported sample sizes (bits): 24 20 16
    AC-3:
      Max channels: 6
      Supported sample rates (kHz): 48 44.1 32
      Maximum bit rate: 640 kb/s
    DTS:
      Max channels: 6
      Supported sample rates (kHz): 48
      Maximum bit rate: 1536 kb/s
  Speaker Allocation Data Block:
    FL/FR - Front Left/Right
  Video Capability Data Block:
    YCbCr quantization: No Data
    RGB quantization: No Data
    PT scan behavior: No Data
    IT scan behavior: Supports both over- and underscan
    CE scan behavior: Supports both over- and underscan
  Colorimetry Data Block:
    xvYCC601
    xvYCC709
    Gamut Boundary Description Metadata Profile P0
  Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
    Source physical address: 2.2.0.0
    Supports_AI
    DC_36bit
    DC_30bit
    DC_Y444
    Maximum TMDS clock: 300 MHz
    Extended HDMI video details:
      HDMI VICs:
        HDMI VIC 1:  3840x2160   30.000000 Hz  16:9     67.500 kHz    297.000000 MHz
        HDMI VIC 2:  3840x2160   25.000000 Hz  16:9     56.250 kHz    297.000000 MHz
        HDMI VIC 3:  3840x2160   24.000000 Hz  16:9     54.000 kHz    297.000000 MHz
        HDMI VIC 4:  4096x2160   24.000000 Hz 256:135   54.000 kHz    297.000000 MHz
  HDR Static Metadata Data Block:
    Electro optical transfer functions:
      Traditional gamma - SDR luminance range
      SMPTE ST2084
      Hybrid Log-Gamma
    Supported static metadata descriptors:
      Static metadata type 1
  YCbCr 4:2:0 Video Data Block:
    VIC  96:  3840x2160   50.000000 Hz  16:9    112.500 kHz    594.000000 MHz
    VIC  97:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz
    VIC 101:  4096x2160   50.000000 Hz 256:135  112.500 kHz    594.000000 MHz
    VIC 102:  4096x2160   60.000000 Hz 256:135  135.000 kHz    594.000000 MHz
  Detailed Timing Descriptors:
    DTD 3:  1920x1080i  50.000000 Hz  16:9     28.125 kHz     74.250000 MHz (1872 mm x 1053 mm)
                 Hfront  528 Hsync  44 Hback  148 Hpol P
                 Vfront    2 Vsync   5 Vback   15 Vpol P Vfront +0.5 Odd Field
                 Vfront    2 Vsync   5 Vback   15 Vpol P Vback  +0.5 Even Field
    DTD 4:  1366x768    59.789541 Hz 683:384   47.712 kHz     85.500000 MHz (1872 mm x 1053 mm)
                 Hfront   70 Hsync 143 Hback  213 Hpol P
                 Vfront    3 Vsync   3 Vback   24 Vpol P
Checksum: 0xbb  Unused space in Extension Block: 21 bytes

Specifically, the following timings no longer work:

    VIC  96:  3840x2160   50.000000 Hz  16:9    112.500 kHz    594.000000 MHz
    VIC  97:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz
    VIC 101:  4096x2160   50.000000 Hz 256:135  112.500 kHz    594.000000 MHz
    VIC 102:  4096x2160   60.000000 Hz 256:135  135.000 kHz    594.000000 MHz

I can replicate the issue on both linux-7.2.3.arch1-2 and linux-zen-7.2.3.arch1-2. As a stop gap, I've reverted to using linux-lts for now.

The GPU is the integrated graphics:

CPU: AMD Ryzen 9 7940HS (16) @ 5.26 GHz
GPU: AMD Radeon 780M Graphics [Integrated]

There's no indication in the logs that the system is aware of anything wrong; I can even remotely connect via Moonlight/Sunshine and the desktop renders as expected. It just seems like the signal being emitted to the TV is out of spec since 7.2.

Last edited by FineWolf (Yesterday 22:09:55)

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#2 Yesterday 22:56:54

loqs
Member
Registered: 2014-03-06
Posts: 19,040

Re: [AMDGPU] 4:2:0 output via HDMI seems broken since kernel 7.2

Possibly related to https://bbs.archlinux.org/viewtopic.php?id=314808?

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#3 Yesterday 23:47:20

FineWolf
Member
Registered: 2026-03-23
Posts: 2

Re: [AMDGPU] 4:2:0 output via HDMI seems broken since kernel 7.2

I ended up opening an issue: https://gitlab.freedesktop.org/drm/amd/ … items/5757

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#4 Today 05:29:54

loqs
Member
Registered: 2014-03-06
Posts: 19,040

Re: [AMDGPU] 4:2:0 output via HDMI seems broken since kernel 7.2

Testing 7.2.0, 7.2-rc1 and 7.3-rc1 would give upstream some more data points.

pacman -U https://pkgbuild.com/\~gromit/linux-bisection-kernels/linux-mainline-7.2-1-x86_64.pkg.tar.zst
pacman -U https://pkgbuild.com/\~gromit/linux-bisection-kernels/linux-mainline-7.2rc1-1-x86_64.pkg.tar.zst
pacman -U https://pkgbuild.com/\~gromit/linux-bisection-kernels/linux-mainline-7.3rc1-1-x86_64.pkg.tar.zst

Last edited by loqs (Today 05:30:04)

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#5 Today 06:30:52

seth
Member
From: Won't reply 2 private help req
Registered: 2012-09-03
Posts: 77,682

Re: [AMDGPU] 4:2:0 output via HDMI seems broken since kernel 7.2

I ended up opening an

… likely duplicate of the upstream bug I linked in the other thread: https://gitlab.freedesktop.org/drm/amd/ … items/5743

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