Hi Maxime, On 06/03/2025 18:17, Maxime Ripard wrote: > edid-decode gained recently support to check that infoframes are > compliant and match the EDID the monitor exposes. > > Since the HDMI helpers provide those infoframes in debugfs, it makes it > easy to check from userspace that the drivers (and helpers) behave > properly. > > Let's document it. > > Cc: Hans Verkuil <hverkuil@xxxxxxxxx> > Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx> > --- > drivers/gpu/drm/display/drm_hdmi_state_helper.c | 240 ++++++++++++++++++++++++ > 1 file changed, 240 insertions(+) > > diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c > index 24bfc82bf9b02bf3201d97432e3c239ccc8714b4..86f812b89f0e51abc24910898c114d6b08a78edf 100644 > --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c > +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c > @@ -16,10 +16,250 @@ > * in the form of KMS helpers. > * > * It contains TMDS character rate computation, automatic selection of > * output formats, infoframes generation, etc. > * > + * Infoframes Compliance > + * ~~~~~~~~~~~~~~~~~~~~~ > + * > + * Drivers using the helpers will expose the various infoframes > + * generated according to the HDMI specification in debugfs. > + * > + * Compliance can then be tested using a recent-enough ``edid-decode`` > + * version (released after summer 2024). A sample run would look like: > + * > + * .. code-block:: bash > + * > + * # edid-decode \ > + * -I /sys/kernel/debug/dri/1/HDMI-A-1/infoframes/audio \ > + * -I /sys/kernel/debug/dri/1/HDMI-A-1/infoframes/avi \ > + * -I /sys/kernel/debug/dri/1/HDMI-A-1/infoframes/hdmi \ > + * -I /sys/kernel/debug/dri/1/HDMI-A-1/infoframes/hdr_drm \ > + * -I /sys/kernel/debug/dri/1/HDMI-A-1/infoframes/spd \ > + * /sys/class/drm/card1-HDMI-A-1/edid \ > + * -c > + * > + * edid-decode (hex): > + * > + * 00 ff ff ff ff ff ff 00 1e 6d f4 5b 1e ef 06 00 > + * 07 20 01 03 80 2f 1a 78 ea 24 05 af 4f 42 ab 25 > + * 0f 50 54 21 08 00 d1 c0 61 40 01 01 01 01 01 01 > + * 01 01 01 01 01 01 56 5e 00 a0 a0 a0 29 50 30 20 > + * 35 00 d1 06 11 00 00 1a 00 00 00 fd 00 3b 3d 1e > + * 70 1e 00 0a 20 20 20 20 20 20 00 00 00 fc 00 4c > + * 47 20 53 44 51 48 44 0a 20 20 20 20 00 00 00 ff > + * 00 32 30 37 4e 54 52 4c 44 43 34 33 30 0a 01 43 > + * > + * 02 03 29 71 23 09 07 07 4b 01 03 04 90 12 13 1f > + * 22 5d 5e 5f 83 01 00 00 6d 03 0c 00 10 00 b8 3c > + * 20 00 60 01 02 03 e2 00 6a 00 00 00 00 00 00 00 > + * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > + * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > + * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > + * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > + * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ee > + * > + * ---------------- > + * > + * Block 0, Base EDID: > + * EDID Structure Version & Revision: 1.3 > + * Vendor & Product Identification: This looks odd: the two lines above should be aligned, but they are not. Some copy-and-paste issue perhaps? > + * Manufacturer: GSM > + * Model: 23540 > + * Serial Number: 454430 (0x0006ef1e) > + * Made in: week 7 of 2022 > + * Basic Display Parameters & Features: > + * Digital display > + * Maximum image size: 47 cm x 26 cm > + * Gamma: 2.20 > + * DPMS levels: Standby Suspend Off > + * RGB color display > + * First detailed timing is the preferred timing > + * Color Characteristics: > + * Red : 0.6835, 0.3105 > + * Green: 0.2587, 0.6679 > + * Blue : 0.1445, 0.0585 > + * 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 > + * DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz > + * Detailed Timing Descriptors: > + * DTD 1: 2560x1440 59.950550 Hz 16:9 88.787 kHz 241.500000 MHz (465 mm x 262 mm) > + * Hfront 48 Hsync 32 Hback 80 Hpol P > + * Vfront 3 Vsync 5 Vback 33 Vpol N > + * Display Range Limits: > + * Monitor ranges (GTF): 59-61 Hz V, 30-112 kHz H, max dotclock 300 MHz > + * Display Product Name: 'LG SDQHD' > + * Display Product Serial Number: '207NTRLDC430' > + * Extension blocks: 1 > + * Checksum: 0x43 > + * > + * ---------------- > + * > + * Block 1, CTA-861 Extension Block: > + * Revision: 3 > + * Basic audio support > + * Supports YCbCr 4:4:4 > + * Supports YCbCr 4:2:2 > + * Native detailed modes: 1 > + * Audio Data Block: > + * Linear PCM: > + * Max channels: 2 > + * Supported sample rates (kHz): 48 44.1 32 > + * Supported sample sizes (bits): 24 20 16 > + * Video Data Block: > + * VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 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 (native) > + * VIC 18: 720x576 50.000000 Hz 16:9 31.250 kHz 27.000000 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 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 95: 3840x2160 30.000000 Hz 16:9 67.500 kHz 297.000000 MHz > + * Speaker Allocation Data Block: > + * FL/FR - Front Left/Right > + * Vendor-Specific Data Block (HDMI), OUI 00-0C-03: > + * Source physical address: 1.0.0.0 > + * 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 > + * Video Capability Data Block: > + * YCbCr quantization: No Data > + * RGB quantization: Selectable (via AVI Q) > + * PT scan behavior: Always Underscanned > + * IT scan behavior: Always Underscanned > + * CE scan behavior: Always Underscanned > + * Checksum: 0xee Unused space in Extension Block: 86 bytes > + * > + * ---------------- > + * > + * edid-decode SHA: 5332a3b76080 2024-11-19 07:53:00 I recommend that you get the latest edid-decode version from https://git.linuxtv.org/v4l-utils.git/ so that the documentation is at least corresponding to the most recent version. Should there be a link to the official git repo as well? > + * > + * Warnings: > + * > + * Block 1, CTA-861 Extension Block: > + * IT Video Formats are overscanned by default, but normally this should be underscanned. > + * Video Data Block: VIC 1 and the first DTD are not identical. Is this intended? > + * Video Data Block: All VICs are in ascending order, and the first (preferred) VIC <= 4, is that intended? > + * Video Capability Data Block: Set Selectable YCbCr Quantization to avoid interop issues. > + * Video Capability Data Block: S_PT is equal to S_IT and S_CE, so should be set to 0 instead. > + * Display Product Serial Number is set, so the Serial Number in the Base EDID should be 0. > + * Add a Colorimetry Data Block with the sRGB colorimetry bit set to avoid interop issues. > + * EDID: > + * Base EDID: Some timings are out of range of the Monitor Ranges: > + * Vertical Freq: 24.000 - 60.317 Hz (Monitor: 59.000 - 61.000 Hz) > + * > + * Failures: > + * > + * Block 1, CTA-861 Extension Block: > + * Video Capability Data Block: IT video formats are always underscanned, but bit 7 of Byte 3 of the CTA-861 Extension header is set to overscanned. > + * EDID: > + * CTA-861: Native progressive timings are a mix of several resolutions. > + * > + * EDID conformity: FAIL > + * > + * ================ > + * > + * InfoFrame of '/sys/kernel/debug/dri/1/HDMI-A-1/infoframes/audio' was empty. > + * > + * ================ > + * > + * edid-decode InfoFrame (hex): > + * > + * 82 02 0d 31 12 28 04 00 00 00 00 00 00 00 00 00 > + * 00 > + * > + * ---------------- > + * > + * HDMI InfoFrame Checksum: 0x31 > + * > + * AVI InfoFrame > + * Version: 2 > + * Length: 13 > + * Y: Color Component Sample Format: RGB > + * A: Active Format Information Present: Yes > + * B: Bar Data Present: Bar Data not present > + * S: Scan Information: Composed for an underscanned display > + * C: Colorimetry: No Data > + * M: Picture Aspect Ratio: 16:9 > + * R: Active Portion Aspect Ratio: 8 > + * ITC: IT Content: No Data > + * EC: Extended Colorimetry: xvYCC601 > + * Q: RGB Quantization Range: Limited Range > + * SC: Non-Uniform Picture Scaling: No Known non-uniform scaling > + * YQ: YCC Quantization Range: Limited Range > + * CN: IT Content Type: Graphics > + * PR: Pixel Data Repetition Count: 0 > + * Line Number of End of Top Bar: 0 > + * Line Number of Start of Bottom Bar: 0 > + * Pixel Number of End of Left Bar: 0 > + * Pixel Number of Start of Right Bar: 0 > + * > + * ---------------- > + * > + * AVI InfoFrame conformity: PASS > + * > + * ================ > + * > + * edid-decode InfoFrame (hex): > + * > + * 81 01 05 49 03 0c 00 20 01 > + * > + * ---------------- > + * > + * HDMI InfoFrame Checksum: 0x49 > + * > + * Vendor-Specific InfoFrame (HDMI), OUI 00-0C-03 > + * Version: 1 > + * Length: 5 > + * HDMI Video Format: HDMI_VIC is present > + * HDMI VIC 1: 3840x2160 30.000000 Hz 16:9 67.500 kHz 297.000000 MHz > + * > + * ---------------- > + * > + * Vendor-Specific InfoFrame (HDMI), OUI 00-0C-03 conformity: PASS > + * > + * ================ > + * > + * InfoFrame of '/sys/kernel/debug/dri/1/HDMI-A-1/infoframes/hdr_drm' was empty. > + * > + * ================ > + * > + * edid-decode InfoFrame (hex): > + * > + * 83 01 19 93 42 72 6f 61 64 63 6f 6d 56 69 64 65 > + * 6f 63 6f 72 65 00 00 00 00 00 00 00 09 > + * > + * ---------------- > + * > + * HDMI InfoFrame Checksum: 0x93 > + * > + * Source Product Description InfoFrame > + * Version: 1 > + * Length: 25 > + * Vendor Name: 'Broadcom' > + * Product Description: 'Videocore' > + * Source Information: PC general > + * > + * ---------------- > + * > + * Source Product Description InfoFrame conformity: PASS > + * > * Testing > * ~~~~~~~ > * > * The helpers have unit testing and can be tested using kunit with: > * > Note that the InfoFrame checks are still rudimentary for the AVI and HDMI InfoFrames. It's on my TODO list to improve this further, but -ENOTIME :-( Regards, Hans
