Wayland monitor not reading refresh rate from DisplayID extension block

Hello, I switched from Windows to Arch ( CachyOS ) recently and am having issues setting up my monitor refresh rate. It supports 4k up to 144hz, but KDE enables only 60hz, I had no such issue with Windows.

❯ kscreen-doctor -o
Output: 1 DP-3
        enabled
        connected
        priority 1
        DisplayPort
        Modes:  1:3840x2160@60*!  2:3840x2160@60  3:3840x2160@60  4:3840x2160@50  5:3840x2160@30  6:3840x2160@30  7:3840x2160@25  8:3840x2160@24  9:3840x2160@24  10:2560x1440@60  11:1920x1200@60  12:1920x1080@60  13:1920x1080@60  14:1920x1080@60  15:1920x1080@60  16:1920x1080@60  17:1920x1080@50  18:1920x1080@30  19:1920x1080@30  20:1920x1080@25  21:1920x1080@24  22:1920x1080@24  23:1600x1200@60  24:1680x1050@60  25:1680x945@60  26:1600x900@60  27:1280x1024@60  28:1440x900@60  29:1280x800@60  30:1280x720@60  31:1280x720@60  32:1280x720@60  33:1280x720@50  34:1280x720@30  35:1280x720@30  36:1280x720@25  37:1280x720@24  38:1280x720@24  39:1024x768@60  40:800x600@60  41:720x480@60  42:720x480@60  43:720x480@60  44:720x480@60  45:640x480@60  46:640x480@60  47:640x480@60  48:1600x1200@60  49:1280x1024@60  50:1024x768@60  51:2560x1600@60  52:1920x1200@60  53:1280x800@60  54:3840x2160@60  55:3200x1800@60  56:2880x1620@60  57:2560x1440@60  58:1920x1080@60  59:1600x900@60  60:1368x768@60  61:1280x720@60 
        Geometry: 0,0 2328x1310
        Scale: 1.65
        Rotation: 1
        Overscan: 0
        Vrr: Automatic
        RgbRange: unknown
        HDR: disabled
        Wide Color Gamut: disabled
        ICC profile: none
        Color profile source: sRGB
        Color power preference: prefer accuracy
        Brightness control: supported, set to 100% and dimming to 100%

It shows all the modes from the Base EDID block, but the 144hz configuration is set in the Block 2, Display ID extension block:

❯ sudo edid-decode < /sys/devices/pci0000:00/0000:00:03.1/0000:07:00.0/0000:08:00.0/0000:09:00.0/drm/card0/card0-DP-3/edid

edid-decode (hex):

00 ff ff ff ff ff ff 00 5c 2d 00 28 00 00 00 00
1f 21 01 04 b5 3e 23 78 2f 87 e5 a4 56 50 9e 26
0d 50 54 21 08 00 d1 c0 b3 c0 81 c0 a9 c0 01 01
01 01 01 01 01 01 4d d0 00 a0 f0 70 3e 80 30 20
35 00 6c 5d 21 00 00 1a 00 00 00 fc 00 43 54 53
50 32 38 2d 42 4c 30 31 0a 20 00 00 00 fd 00 30
96 ff ff 87 01 0a 20 20 20 20 20 20 00 00 00 ff
00 0a 20 20 20 20 20 20 20 20 20 20 20 20 02 61

02 03 2e f2 53 61 01 02 03 04 10 13 1f 20 21 22
3c 3d 3e 4c 5d 5e 5f 60 e2 00 d5 23 09 7f 07 83
01 00 00 e3 05 c0 00 e6 06 05 01 62 62 00 02 3a
80 18 71 38 2d 40 58 2c 25 00 6c 5d 21 00 00 1a
56 5e 00 a0 a0 a0 29 50 30 20 35 00 6c 5d 21 00
00 1a 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 83

70 12 6a 02 00 03 00 3c 87 58 01 88 ff 0e 9f 00
2f 80 1f 00 6f 08 2c 00 02 00 04 00 6f 9d 01 08
ff 0e 9f 00 2f 80 1f 00 6f 08 2c 00 02 00 04 00
a1 ed 01 08 ff 0e b3 00 2f 80 1f 00 6f 08 16 00
01 00 01 00 01 03 0c 80 17 49 0d 00 0f 70 08 00
78 4d 00 07 00 0a 08 81 00 08 04 00 04 02 10 00
81 00 04 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 42 90

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

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.4
  Vendor & Product Identification:
    Manufacturer: WAM
    Model: 10240
    Made in: week 31 of 2023
  Basic Display Parameters & Features:
    Digital display
    Bits per primary color channel: 10
    DisplayPort interface
    Maximum image size: 62 cm x 35 cm
    Gamma: 2.20
    DPMS levels: Off
    Supported color formats: RGB 4:4:4, YCrCb 4:4:4
    Default (sRGB) color space is primary color space
    First detailed timing includes the native pixel format and preferred refresh rate
    Display supports continuous frequencies
  Color Characteristics:
    Red  : 0.6425, 0.3359
    Green: 0.3134, 0.6201
    Blue : 0.1513, 0.0527
    White: 0.3134, 0.3291
  Established Timings I & II:
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
  Standard Timings:
    DMT 0x52:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz
    GTF     :  1680x945    59.999909 Hz  16:9     58.680 kHz    131.443000 MHz
    DMT 0x55:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    DMT 0x53:  1600x900    60.000000 Hz  16:9     60.000 kHz    108.000000 MHz (RB)
  Detailed Timing Descriptors:
    DTD 1:  3840x2160   59.996625 Hz  16:9    133.312 kHz    533.250000 MHz (620 mm x 349 mm)
                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync   5 Vback   54 Vpol N
    Display Product Name: 'CTSP28-BL01'
    Display Range Limits:
      Monitor ranges (Range Limits Only): 48-150 Hz V, 255-255 kHz H, max dotclock 1350 MHz
    Display Product Serial Number: ''
  Extension blocks: 2
Checksum: 0x61

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

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: 2
  Video Data Block:
    VIC  97:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz
    VIC   1:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    VIC   2:   720x480    59.940060 Hz   4:3     31.469 kHz     27.000000 MHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz     27.000000 MHz
    VIC   4:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz
    VIC  19:  1280x720    50.000000 Hz  16:9     37.500 kHz     74.250000 MHz
    VIC  31:  1920x1080   50.000000 Hz  16:9     56.250 kHz    148.500000 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  60:  1280x720    24.000000 Hz  16:9     18.000 kHz     59.400000 MHz
    VIC  61:  1280x720    25.000000 Hz  16:9     18.750 kHz     74.250000 MHz
    VIC  62:  1280x720    30.000000 Hz  16:9     22.500 kHz     74.250000 MHz
    VIC  76:  1920x1080   60.000000 Hz  64:27    67.500 kHz    148.500000 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  95:  3840x2160   30.000000 Hz  16:9     67.500 kHz    297.000000 MHz
    VIC  96:  3840x2160   50.000000 Hz  16:9    112.500 kHz    594.000000 MHz
  Video Capability Data Block:
    YCbCr quantization: Selectable (via AVI YQ)
    RGB quantization: Selectable (via AVI Q)
    PT scan behavior: Always Overscanned
    IT scan behavior: Always Overscanned
    CE scan behavior: Always Overscanned
  Audio Data Block:
    Linear PCM:
      Max channels: 2
      Supported sample rates (kHz): 192 176.4 96 88.2 48 44.1 32
      Supported sample sizes (bits): 24 20 16
  Speaker Allocation Data Block:
    FL/FR - Front Left/Right
  Colorimetry Data Block:
    BT2020YCC
    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: 98 (417.710 cd/m^2)
    Desired content max frame-average luminance: 98 (417.710 cd/m^2)
    Desired content min luminance: 0 (0.000 cd/m^2)
  Detailed Timing Descriptors:
    DTD 2:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (620 mm x 349 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    2 Vsync   5 Vback   38 Vpol N
    DTD 3:  2560x1440   59.950550 Hz  16:9     88.787 kHz    241.500000 MHz (620 mm x 349 mm)
                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync   5 Vback   33 Vpol N
Checksum: 0x83  Unused space in Extension Block: 45 bytes

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

Block 2, DisplayID Extension Block:
  Version: 1.2
  Extension Count: 0
  Display Product Type: Display panel or other transducer, LCD or PDP module, etc.
  Video Timing Modes Type 1 - Detailed Timings Data Block:
    DTD:  3840x2160  100.000000 Hz   0:0    220.500 kHz    882.000000 MHz (aspect undefined, no 3D stereo, preferred)
               Hfront   48 Hsync  32 Hback   80 Hpol P
               Vfront    3 Vsync   5 Vback   37 Vpol N
    DTD:  3840x2160  120.000000 Hz   0:0    264.600 kHz   1058.400000 MHz (aspect undefined, no 3D stereo)
               Hfront   48 Hsync  32 Hback   80 Hpol P
               Vfront    3 Vsync   5 Vback   37 Vpol N
    DTD:  3840x2160  144.000565 Hz   0:0    314.353 kHz   1263.700000 MHz (aspect undefined, no 3D stereo)
               Hfront   48 Hsync  32 Hback  100 Hpol P
               Vfront    2 Vsync   2 Vback   19 Vpol N
  Display Parameters Data Block (0x01):
    Image size: 601.6 mm x 340.1 mm
    Display native pixel format: 3840x2160
    Gamma: 2.20
    Aspect ratio: 1.77
    Dynamic bpc native: 1
    Dynamic bpc overall: 1
  Supported Timing Modes Type 1 - VESA DMT Timings Data Block:
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 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 0x33:  1600x1200   60.000000 Hz   4:3     75.000 kHz    162.000000 MHz
    DMT 0x3a:  1680x1050   59.954250 Hz  16:10    65.290 kHz    146.250000 MHz
    DMT 0x45:  1920x1200   59.884600 Hz  16:10    74.556 kHz    193.250000 MHz
  CTA-861 DisplayID Data Block:
  Unknown CTA-861 Data Block (tag 0x00, length 0):
  Unknown CTA-861 Data Block (tag 0x00, length 0):
  Unknown CTA-861 Data Block (tag 0x00, length 0):
  Unknown CTA-861 Data Block (tag 0x00, length 0):
  Checksum: 0x00 (should be 0x42)
Checksum: 0x90  Unused space in Extension Block: 15 bytes

Not sure if relevant ( or if expected ) but HDR can be enabled but it is defined in the Block 1, CTA-861 Extension Block, which doesn’t define the 144hz support, it is only done so in Block 1, DisplayID Extension Block`.

Is something up with the EDID block? If so, is there a way I can “overwrite” fixing the issue? Or is this EDID simply not supported in wayland/kde ?

KWin doesn’t read the EDID to find out the supported modes, it just gets a list from the kernel driver.

The best way to get this fixed is to directly complain to your graphics vendor - at https://gitlab.freedesktop.org/drm/amd/-/issues for AMD, Linux - NVIDIA Developer Forums for NVidia or Issues · drm / i915 / kernel · GitLab for Intel.

Thank you, I opened a issue for amd: https://gitlab.freedesktop.org/drm/amd/-/issues/3988