drm_crtc_add_crc_entry(9)

💖 drm_crtc_add_crc_entry(9) 💖

okay so bestie, we're in the Kernel API Manual today and the star of the show is drm_crtc_add_crc_entry(9) ✨ it's giving "tiny function, huge responsibilities" ngl 🫶

---

🌸 NAME 🌸

drm_crtc_add_crc_entry — Add entry with CRC information for a frame 🎀

---

🦋 SYNOPSIS 🦋

int drm_crtc_add_crc_entry (struct drm_crtc *crtc , bool has_frame ,
       uint32_t frame , uint32_t *crcs );

like, look at her. four args. no notes. 💅

---

✨ ARGUMENTS ✨

• crtc — the CRTC that this frame belongs to 👑 like whose frame is this anyway
• has_frame — a bool telling us whether this entry actually has a frame number to go with it 🫶 sometimes yes, sometimes no, we don't judge
• frame — the number of the frame these CRCs are all about 🔥 (uint32_t, in case you were wondering)
• crcs — array of CRC values 💖 and its length has to match #drm_crtc_crc.values_cnt, no cap, that's the vibe check 📏

---

🌈 DESCRIPTION 🌈

so for each and every frame, the driver goes and polls the source of CRCs for new data 💫 and then it calls this function to add them to the buffer — the very same buffer that userspace reads from. that's it. that's the whole gig. iconic honestly 🎀

like it's literally the handoff: driver gets the numbers, this function tucks them into the buffer, userspace comes along and reads them. middle manager energy but make it kernel 🧚

---

💜 SEE ALSO 💜

• Kernel file ./drivers/gpu/drm/drm_debugfs_crc.c 📁
• CRC ABI(9) ⭐

---

bestie reminder: crcs length must match #drm_crtc_crc.values_cnt — don't come for me if you skip that 🙈

---

and that's the page!! mwah 💋 this little writeup lives in ./drivers/gpu/drm, dated October 2026, and it's filed under drm_crtc_add_crc_entry(9) — slay, go read some CRC ABI now, ily 🫶💖✨