drm/amd/display: clamp cursor hotspot at the register write

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[Why]
dcn401_build_cursor_position() clamped x_hotspot to 0xFF before
publishing *pos_out, but that field is also stored into hubp->curs_pos
and forwarded to dpp1_set_cursor_position(), which derives
src_x_offset from it. The ODM/MPC slice adjustments earlier in the same
function deliberately grow x_hotspot past 255 to keep the cursor
visible across a slice boundary, so the clamp corrupted DPP source
addressing in exactly the case it was meant to handle.

[How]
Clamp in hubp401_cursor_set_position() instead, where the 8-bit
CURSOR_HOT_SPOT_X field lives. A local is used for the register write
only; pos->x_hotspot passes through unmodified.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Piotr Maziarz <piotr.maziarz@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Piotr Maziarz 2026-08-17 14:25:34 +02:00 • committed by Alex Deucher

parent 08a07e8c25

commit 184a71e58b

2 changed files with 3 additions and 5 deletions

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4

drivers/gpu/drm/amd/display/dc/hubp/dcn401/dcn401_hubp.c

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4

drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c

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