drm_gem_sim...ow_fb_access(9)

📦 version 7.3.1, in nixpkgs unstable

💖 drm_gem_simple_kms_begin_shadow_fb_access — bestie edition 💖

okay so this is a page straight out of the Kernel API Manual, and it's about drm_gem_simple_kms_begin_shadow_fb_access — which, yes, is a whole mouthful, but it's literally just the function that prepares shadow framebuffers for CPU access. say it with me: prep the shadow fb so the CPU can touch it. iconic behaviour honestly 🎀

✨ SYNOPSIS ✨

int drm_gem_simple_kms_begin_shadow_fb_access (struct
     drm_simple_display_pipe *pipe , struct drm_plane_state *plane_state );

like, it takes two things and gives you back an int. no cap. 💅

🦋 ARGUMENTS 🦋

  • pipe — the simple display pipe. that's the vibe. that's the whole thing.
  • plane_state — the plane state, and heads up, it's of type struct drm_shadow_plane_state 👀

🌸 DESCRIPTION 🌸

so what this function does is implement struct drm_simple_display_funcs.begin_fb_access. that's the assignment, that's the job, she ate 🍓

for the full details you gotta go read drm_gem_begin_shadow_fb_access, and when you're done and you need to clean up, that's drm_gem_simple_kms_cleanup_shadow_fb's moment to shine ✨

🌈 RETURN 🌈

  • 0 on success 🫶
  • a negative errno code otherwise 😭

that's it. that's the whole return contract. periodt.

👑 SEE ALSO 👑

the kernel file lives at ./drivers/gpu/drm/drm_gem_atomic_helper.c — that's the home base, and here's the whole friend group:

like, go read them. all of them. i'll wait 💜

ngl the function name is so long it barely fits in the header, which is why the title is all truncated like drm_gem_sim...ow_fb_access(9) — she's mysterious, she's abbreviated, she contains multitudes 💀

and that's the page!! this one came from ./drivers/gpu/drm, dated October 2026, dropping out of the Kernel API Manual like the main character she is 🧚‍♀️ mwah, go prep those shadow framebuffers, bestie 💅💖

📦 where this page comes from