drm_mode_gamma_set_ioctl(9)

💅 drm_mode_gamma_set_ioctl(9) — a Kernel API Manual moment

okay bestie, so this is a page from the Kernel API Manual (yes, the drm_mode_gamma_set_ioctl(9) one, we stan a niche legend) and it's literally all about setting the gamma table. let's get into it ✨

---

🌸 NAME 🌸

drm_mode_gamma_set_ioctl — set the gamma table, that's the whole vibe 🎀

---

✨ SYNOPSIS ✨

int drm_mode_gamma_set_ioctl (struct drm_device *dev , void *data ,
       struct drm_file *file_priv );

like, look at that signature. gorgeous. no notes. 👑

---

🫶 ARGUMENTS 🫶

• dev — the DRM device, aka the main character 🖥️
• data — the ioctl data, the little payload carrying the goods 📦
• file_priv — DRM file info, the receipts basically 🧾

---

🦋 DESCRIPTION 🦋

So what it does: it sets the gamma table of a CRTC to the one that got passed in by the user. that's it, that's the job 💖

and if userspace is like "wait, how big is this table supposed to be??" — no stress, they can inquire the required gamma table size through drm_mode_gamma_get_ioctl. iykyk ✨

also, important: this one is called by the user via ioctl. so it's the userspace-to-kernel pipeline, fr fr.

---

🔥 RETURN 🔥

• Zero on success 🎉 (we love a clean win)
• negative errno on failure 😭 (it's giving error, but at least it's a proper errno)

---

🌈 SEE ALSO 🌈

the whole friend group, ok:

• the kernel file ./drivers/gpu/drm/drm_color_mgmt.c
• overview(9)
• drm_color_ctm_s31_32_to_qm_n(9)
• drm_crtc_enable_color_mgmt(9)
• drm_mode_crtc_set_gamma_size(9)
• drm_crtc_supports_legacy_gamma(9)
• drm_crtc_legacy_gamma_set(9)
• drm_mode_gamma_get_ioctl(9)
• drm_get_color_encoding_name(9)
• drm_get_color_range_name(9)
• drm_plane_create_color_properties(9)
• drm_color_lut_check(9)
• drm_crtc_load_gamma_888(9)
• drm_crtc_load_gamma_565_from_888(9)
• drm_crtc_load_gamma_555_from_888(9)
• drm_crtc_fill_gamma_888(9)
• drm_crtc_fill_gamma_565(9)
• drm_crtc_fill_gamma_555(9)
• drm_crtc_load_palette_8(9)
• drm_crtc_fill_palette_332(9)
• drm_crtc_fill_palette_8(9)
• drm_color_lut32_check(9)

---

💀 quick vibe check: this page lives under ./drivers/gpu/drm, and it's dated October 2026 — so yeah, future energy, we love to see it 🧚

okay that's the whole page, go forth and set those gamma tables responsibly, bestie 💜🌸🍓