STRUCT DP_SDP(9)

💖 struct dp_sdp — DP secondary data packet (from the Kernel API Manual, bestie) 💖

Okay so real talk, this is a page straight out of the Kernel API Manual, and it's describing one little struct that's basically the gossip packet of DisplayPort: it carries the side info. Let's go. 🎀

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✨ NAME ✨

struct dp_sdp — DP secondary data packet 👑

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🌈 SYNOPSIS 🌈

struct dp_sdp {
    struct dp_sdp_header sdp_header;
    u8 db[32];
 };

That's it. That's the whole vibe. A header plus 32 bytes of db. ✨

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🦋 Members 🦋

• sdp_header — the DP secondary data packet header. It's giving "cover page energy" 🫶
• db — the DP secondaray data packet data blocks (yes that spelling is in the source, periodt, I don't make the rules 💀). This is where it gets juicy, because db gets read two different ways depending on which payload you're looking at:

🍓 VSC SDP Payload for PSR

• db[0]: Stereo Interface
• db[1]: 0 - PSR State; 1 - Update RFB; 2 - CRC Valid
• db[2]: CRC value bits 7:0 of the R or Cr component
• db[3]: CRC value bits 15:8 of the R or Cr component
• db[4]: CRC value bits 7:0 of the G or Y component
• db[5]: CRC value bits 15:8 of the G or Y component
• db[6]: CRC value bits 7:0 of the B or Cb component
• db[7]: CRC value bits 15:8 of the B or Cb component
• db[8] - db[31]: Reserved 🙈

🌸 VSC SDP Payload for Pixel Encoding/Colorimetry Format

• db[0] - db[15]: Reserved
• db[16]: Pixel Encoding and Colorimetry Formats
• db[17]: Dynamic Range and Component Bit Depth
• db[18]: Content Type
• db[19] - db[31]: Reserved 💅

lowkey note: both of those maps describe the same db[32] array — they're just two different readings of it, so don't come for me if you noticed the overlap, iykyk 🧚

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👀 SEE ALSO 👀

• Kernel file ./include/drm/display/drm_dp.h
• struct dp_sdp_header(9)
• enum dp_pixelformat(9)
• enum dp_colorimetry(9)
• enum dp_dynamic_range(9)
• enum dp_content_type(9)

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and that's the whole page, bestie — no cap ✨

sign-off time 🎀: this little icon lives in ./include/drm/display and the page is dated October 2026. go forth and slay your DP payloads 💜