subvp_vblank_schedulable(9)

✨ subvp_vblank_schedulable(9) ✨

okay bestie, so this is a page from the Kernel API Manual for the function subvp_vblank_schedulable, and honestly? it's giving "can this display config actually happen or are we delulu" 💅

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🌸 NAME 🌸

subvp_vblank_schedulable — literally the function that tells you whether a SubVP + VBLANK config is schedulable or not. no cap, that's the whole job 🫶

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🦋 SYNOPSIS 🦋

bool subvp_vblank_schedulable (struct dc *dc , struct dc_state *context );

it returns a bool, bestie. yes or no. iconic behavior honestly ✨

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🎀 ARGUMENTS 🎀

• dc — the current dc state, like the vibe right now 🫧
• context — the new dc state, aka the glow-up we're tryna schedule 💖

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👑 DESCRIPTION 👑

so here's the high level algorithm, and yes we're walking through it step by step because that's just how we do 💅

1. Get the timing for the SubVP pipe, the phantom pipe, and the VBLANK pipe. get those numbers, queen 🧚
2. If:

(SubVP Active - Prefetch > Vblank Frame Time + max(MALL region, Vblank blanking time))

then report the configuration as supported. like, that's it, that's the check. if that inequality hits, we're slaying 🔥

3. If the VBLANK display is DRR, then take the DRR static schedulability path instead. different route, same energy 🌈

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⭐ RETURN ⭐

• true if the SubVP + VBLANK/DRR config is schedulable 💖
• false otherwise 😭 (sad but we move)

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🍓 SEE ALSO 🍓

bestie the friend group is LARGE and I love them all:

• Kernel file ./drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c — that's the home base 🏠
• dcn32_helper_populate_phantom_dlg_params(9)
• dcn32_set_phantom_stream_timing(9)
• dcn32_get_num_free_pipes(9)
• dcn32_assign_subvp_pipe(9)
• dcn32_enough_pipes_for_subvp(9)
• subvp_subvp_schedulable(9)
• subvp_drr_schedulable(9)
• subvp_subvp_admissable(9)
• subvp_validate_static_schedulability(9)
• dcn32_allow_subvp_high_refresh_rate(9)
• dcn32_determine_max_vratio_prefetch(9)
• dcn32_assign_fpo_vactive_candidate(9)
• dcn32_find_vactive_pipe(9)

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anyway that's the whole page 🫶 this beauty lives over in ./drivers/gpu/drm/amd/display/... and the docs are dated October 2026 — go off, calendar 📅✨ bye bestie, drink some water and check your inequalities 💜