get_prefetch_end_line(9)

💅 get_prefetch_end_line ✨

okay so bestie, we're in the Kernel API Manual today and this little function is genuinely the group chat's designated calculator 🧮💖

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🌸 NAME 🌸

get_prefetch_end_line — the helper bestie that calculates your prefetch end line for you 🎀

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✨ SYNOPSIS ✨

int32_t get_prefetch_end_line (uint32_t vtotal , uint16_t vblank_end ,
       uint16_t recout_y , uint8_t prefetch_relative_vblank , uint16_t
       dst_y_after_scaler );

like, that's the whole signature, no cap 👑

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🦋 ARGUMENTS 🦋

okay so the docs here are lowkey mysterious, and honestly? not me gatekeeping — the manpage literally says -- undescribed -- for every single one of these, so I'm passing the tea along exactly as I got it 🙈:

• vtotal — -- undescribed -- 💀
• vblank_end — -- undescribed -- 💀
• recout_y — -- undescribed -- 💀
• prefetch_relative_vblank — -- undescribed -- 💀
• dst_y_after_scaler — -- undescribed -- 💀

no fr, that's all we've got. iconic of the documentation, honestly 🫶

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💜 DESCRIPTION 💜

okay so here's the vibe: this one is to be used by FW to calculate and store the prefetch_end_line, so it doesn't need to be computed multiple times 🔥

like, it's giving "do the math once, then chill" — main character energy efficiency ✨

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🌈 RETURN 🌈

it calculates prefetch end given the input timing params 🎯

and then, for reasons known only to the author, there's a whole dramatic row of asterisks:

***********************************************************************************************************

slay, I guess? 💅 (yes, that's literally in the source, I'm not kidding)

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👑 SEE ALSO 👑

• Kernel file — ./drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src/dml2_standalone_libraries/alternate_pstate_shared_lib.c
• in_circular_range(9)
• apply_svp1_workaround(9)
• calculate_start_line_and_height_from_swath(9)
• get_swath_deadlines(9)
• calculate_swath_deadline_dst(9)
• is_dst_in_next_frame(9)
• is_end_swath_in_next_frame(9)
• is_svp_dst_in_next_frame(9)
• calculate_swath_idx_from_dst(9)
• populate_svp_params(9)
• populate_start_index_num_swaths_helper(9)
• calculate_start_index_num_swaths(9)
• calculate_hubp_start_end_lines(9)
• get_effective_vblank_start(9)

that's the whole friend group right there, go say hi to all of them 🦋💖

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💀 real talk though: the doc says -- undescribed -- on all five args, so don't be out here guessing at what they do, bestie. facts only.

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kisses, this page lives at ./drivers/gpu/drm/amd/display/... and it's dated October 2026 🎀 mark your calendars, stay hydrated, and remember: get_prefetch_end_line(9) loves you 💜✨🌸