mirror_ubuntu-kernels/drivers/gpu/drm/amd
Ville Syrjälä 7707dd6022 drm/dp_mst: Fix fractional DSC bpp handling
The current code does '(bpp << 4) / 16' in the MST PBN
calculation, but that is just the same as 'bpp' so the
DSC codepath achieves absolutely nothing. Fix it up so that
the fractional part of the bpp value is actually used instead
of truncated away. 64*1006 has enough zero lsbs that we can
just shift that down in the dividend and thus still manage
to stick to a 32bit divisor.

And while touching this, let's just make the whole thing more
straightforward by making the passed in bpp value .4 binary
fixed point always, instead of having to pass in different
things based on whether DSC is enabled or not.

v2:
- Fix DSC kunit test cases.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: David Francis <David.Francis@amd.com>
Cc: Mikita Lipski <mikita.lipski@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Fixes: dc48529fb1 ("drm/dp_mst: Add PBN calculation for DSC modes")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[Imre: Fix kunit test cases]
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-3-imre.deak@intel.com
2023-11-08 17:22:05 +02:00
..
acp
amdgpu Merge tag 'drm-misc-next-2023-09-27' of git://anongit.freedesktop.org/drm/drm-misc into drm-next 2023-09-29 08:27:15 +10:00
amdkfd drm/amdkfd: Insert missing TLB flush on GFX10 and later 2023-09-12 17:45:40 -04:00
amdxcp drm/amdxcp: fix Makefile to build amdxcp module 2023-06-09 12:32:53 -04:00
display drm/dp_mst: Fix fractional DSC bpp handling 2023-11-08 17:22:05 +02:00
include drm/amdgpu: Store CU info from all XCCs for GFX v9.4.3 2023-09-11 18:16:31 -04:00
pm drm/amdgpu: fix retry loop test 2023-09-11 18:19:03 -04:00