update_subv...o_mall_start(9)

💅 update_subvp_prefetch_end_to_mall_start — like, the Kernel API Manual page, bestie ✨

okay so this one is a 9 section page (kernel API vibes, iykyk) and the function is update_subvp_prefetch_end_to_mall_start — yes that's a whole mouthful, we love a long name 🫶

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🌸 NAME 🌸

update_subvp_prefetch_end_to_mall_start — the helper bestie for the SubVP + SubVP case ✨ lowkey crucial, no cap.

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🎀 SYNOPSIS 🎀

void update_subvp_prefetch_end_to_mall_start (struct dc *dc , struct
dc_state *context , union dmub_rb_cmd *cmd , struct pipe_ctx
*subvp_pipes[] );

literally just copy that signature exactly, bestie, don't retype it from memory 😭

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🦋 ARGUMENTS 🦋

• dc [in] — the current dc state, like the state you're in right now 💖
• context [in] — the new dc state, the glow-up version ✨
• cmd [in] — the DMUB cmd that's gonna get populated with SubVP info 🎀
• subvp_pipes [in] — array of SubVP pipes, and heads up: it should always be length 2 👀 (yes, exactly 2, not 3, not 1, two.)

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💜 DESCRIPTION 💜

okay so here's the tea 🍓 — for SubVP + SubVP, we use a single vertical interrupt to start the microschedule for both SubVP pipes. main character energy, one interrupt doing double duty 💅

but for that to actually work correctly? the MALL REGION of both SubVP pipes has to start at the same time. like, synchronized. together. periodt. 🌈

so what this function does: it lengthens the prefetch end to mall start delay of the SubVP pipe that has the shorter prefetch 🌸 — so that both MALL REGION's will start at the same time. it's giving matchmaker, honestly. it's giving "we're leaving at the same time whether you're ready or not" 🧚

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🔥 SEE ALSO 🔥

• Kernel file ./drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c — go read the source, bestie, it's all there 📖
• populate_subvp_cmd_drr_info(9)
• populate_subvp_cmd_vblank_pipe_info(9)
• populate_subvp_cmd_pipe_info(9)
• dc_dmub_setup_subvp_dmub_command(9)
• dc_send_update_cursor_info_to_dmu(9)

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and that's the whole page, bestie 🫶 this one lives over in ./drivers/gpu/drm/amd/display/dc, it's from the Kernel API Manual crowd, and it's dated October 2026 ⭐ — slay, go read the other five functions too 💖🎀💅