populate_svp_params(9)

💅 NAME 💅

Okay bestie, welcome to the Kernel API Manual page for populate_svp_params(9) — this is the helper function that calculates start_idx and number of swaths for a single svp. That's the whole name vibe, periodt. ✨

✨ SYNOPSIS ✨

void populate_svp_params (uint16_t prefetch_swaths , uint16_t
       total_swaths , uint32_t svp_start_swath_idx , uint32_t svp_end_swath_idx
       , uint32_t *svp_start_sw_idx , uint32_t *svp_num_swaths );

🌸 ARGUMENTS 🌸

Bestie, the source is giving us absolutely no description for these, so I'm keeping it 100:

• prefetch_swaths — -- undescribed --
• total_swaths — -- undescribed --
• svp_start_swath_idx — -- undescribed --
• svp_end_swath_idx — -- undescribed --
• svp_start_sw_idx — -- undescribed --
• svp_num_swaths — -- undescribed --

🦋 DESCRIPTION 🦋

Okay so the vibe check here is strict: this function only calculates parameters for ONE of curr or next for a single svp. Not both. Not a little mix. ONE. 😭

That means the caller of this function MUST separate the swath indices to be within the span of a single frame — the swath indices literally cannot span across frame boundaries. No cap, that's the rule. 💅

🌈 SEE ALSO 🌈

Kernel file ./drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src/dml2_standalone_libraries/alternate_pstate_shared_lib.c

And here's the rest of the friend group, all linked and iconic:

• 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_start_index_num_swaths_helper(9)
• calculate_start_index_num_swaths(9)
• calculate_hubp_start_end_lines(9)
• get_prefetch_end_line(9)
• get_effective_vblank_start(9)

Byeee 🫶 — source/version footer says ./drivers/gpu/drm/amd/display/..., dated October 2026, page populate_svp_params(9). Mwah! 💋