intel_fdi_atomic_check_link(9)

💅 intel_fdi_atomic_check_link 💅

okay so bestie, welcome to the kernel API manual for intel_fdi_atomic_check_link(9) — yes it's a mouthful, no we're not renaming it, and honestly it's kind of iconic that a function this long-named is out here doing the most important vibe check on your FDI links 🦋

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✨ NAME ✨

intel_fdi_atomic_check_link — the one that checks all your modeset FDI link configuration. like, all of it. every single one. no cap 💅

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🌸 SYNOPSIS 🌸

int intel_fdi_atomic_check_link (struct intel_atomic_state *state ,
       struct intel_link_bw_limits *limits );

that's the whole signature, bestie, copy it exactly, don't get creative 📝

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🎀 ARGUMENTS 🎀

• state — the intel atomic state. yes. that one. the main character of this whole operation 👑
• limits — the link BW limits. bandwidth boundaries. the rules of engagement 🫶

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💖 DESCRIPTION 💖

so here's the tea: this function checks the link configuration for all modeset FDI outputs. every single one, no skipping, no picking favourites 🌈

and if the configuration is invalid? don't panic — limits will get updated if possible to reduce the total BW. the way it tries to make things work out is honestly so generous of it 😭

but here's the catch, and it's a real one: after that happens, the configuration for all CRTCs in state must be recomputed with the updated limits. not some of them. not the ones you feel like. all of them. periodt 💀

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🔥 RETURN 🔥

• 0 — slay, the configuration is valid ✅
• -EAGAIN — the configuration is invalid and limits got updated with fallback values, with which the configuration of all CRTCs in state must be recomputed. so like, it's not over, you just gotta run it back 🔁
• Other negative error — the configuration is invalid without a fallback possibility, or the check failed for another reason. yeah. that one hurts 🙈

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⭐ SEE ALSO ⭐

• Kernel file ./drivers/gpu/drm/i915/display/intel_fdi.c — go read the source, it's giving lore 👀
• intel_fdi_add_affected_crtcs(9) — its friend, also worth a look 🧚

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fr fr bestie, if you get -EAGAIN do not just ignore it — that's a "recompute all the CRTCs in state" situation, and the manpage said it twice so you know it's serious 💜

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and that's the whole page! written from ./drivers/gpu/drm/i915/display, dated October 2026, and yes the page name is still intel_fdi_atomic_check_link(9) because we don't do rebrands here 💅✨ bye bestie, go check those links 🦋