linux.git/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src, branch master

drm/amd/display: add pstate schedule admissibility flags and frame-time utility

2026-04-17T19:23:59+00:00

[Why]
Core needs to track pstate schedule admissibility for different global
change scenarios (fclk, temp read, PPT) and requires a reusable way to compute
per-stream frame time from timing parameters.

[How]
Extend dml2_core_internal_mode_support_info with:
fclk_pstate_schedule_admissible
temp_read_pstate_schedule_admissible
ppt_pstate_schedule_admissible
Add dummy_double_array[3][DML2_MAX_PLANES] to
dml2_core_calcs_mode_support_locals.
Introduce dml2_core_utils_get_frame_time_us() in dml2_core_utils.c and export
it in dml2_core_utils.h to compute frame time in microseconds from stream
timing (vline time * (vactive + vblank)).

Reviewed-by: Dillon Varone 
Signed-off-by: Wenjing Liu 
Signed-off-by: Aurabindo Pillai 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: add const qualifiers to watermark params struct

2026-04-17T19:23:56+00:00

[why]
There are few non const input pointer fields. Setting them to const to
prevent future modification of read-only data.

Reviewed-by: Dillon Varone 
Signed-off-by: Wenjing Liu 
Signed-off-by: Aurabindo Pillai 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: fix math_mod() using arg1 instead of arg2

2026-04-17T19:23:49+00:00

[Why]
math_mod() multiplied by arg1 instead of arg2, returning a wrong
result for any non-trivial modulo operation.

[How]
Replace arg1 with arg2 in the subtraction term to correctly
implement fmod(arg1, arg2).

Cc: Mario Limonciello 
Cc: Alex Deucher 
Cc: stable@vger.kernel.org
Reviewed-by: Dillon Varone 
Signed-off-by: Wenjing Liu 
Signed-off-by: Aurabindo Pillai 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Remove Duplicate Prefetch Parameter

2026-04-17T19:21:43+00:00

[Why/How]
UrgLatency value is passed in twice to the prefetch calculations.
Once through the UrgentLatency term and once through the Turg term.
Only Turg is used in the prefetch calculation so remove the unused UrgentLatency parameter

Reviewed-by: Dillon Varone 
Signed-off-by: Zheng, Austin 
Signed-off-by: Roman Li 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Add DCN42 PMO policy for DML2.1

2026-04-17T19:21:38+00:00

[Why]
The MinTTU policy in DML2.1 does not guarantee that we support p-state
in blank. This is a delta vs dml2 and earlier revisions as the prefetch
mode override has been removed in favor of a more configurable pstate
optimizer.

[How]
Split off DCN42 with its own PMO helpers so that we can use a simpler
strategy of only allowing the mode if we support p-state in vblank and
if vactive has enough latency hiding.

The actual hookup to use these helpers in the PMO factory will be
done in a later patch to satisfy build system requirements.

Reviewed-by: Dillon Varone 
Signed-off-by: Nicholas Kazlauskas 
Signed-off-by: Roman Li 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fix HostVMMinPageSize unit mismatch in DML2.1

2026-04-17T19:21:12+00:00

[Why]
This was found back on DML2 but was missed when creating DML2.1.

The bottom layer calculation (CalculateHostVMDynamicLevels) expects
a value in bytes, not KB, but we pass in the value in KB (eg. 4).

This causes an extra page table level to be required in the prefetch
bytes which can be significant overhead - preventing some modes
from being supported that should otherwise be.

[How]
Correct the units by multiplying the input and override values by 1024.

Reviewed-by: Austin Zheng 
Signed-off-by: Nicholas Kazlauskas 
Signed-off-by: Roman Li 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: update dcn42 bounding box

2026-04-17T19:11:58+00:00

[why]
update according hw spec.

Reviewed-by: Dillon Varone 
Signed-off-by: Charlene Liu 
Signed-off-by: Roman Li 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Drop unused tiling formats from dml2

2026-04-17T18:54:17+00:00

Remove unused legacy tiling format support from dml2.
Legacy asics don't use dml2.

Fixes: e56e3cff2a1b ("drm/amd/display: Sync dcn42 with DC 3.2.373")
Reviewed-by: Leo Li 
Signed-off-by: Roman Li 
Signed-off-by: Alex Deucher

drm/amd/display: Fix unused parameters warnings in dml2_0

2026-04-17T18:54:11+00:00

[Why] Resolve warnings by marking unused parameters explicitly.

[How] Keep parameter names in signatures and add a line with
     '(void)param;'  inside the function body

Preserved function signatures and avoids breaking code paths that
may reference the parameter under conditional compilation.

Reviewed-by: Dillon Varone 
Reviewed-by: Clayton King 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: Roman Li 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fix bounds checking in dml2_0 clock table array

2026-03-30T18:40:20+00:00

[Why]
Multiple locations in dml2_0 used num_clk_values-1 as array index
without checking if num_clk_values > 0. When num_clk_values is 0,
this results in accessing array index -1, which wraps to 255 for
unsigned types, causing out-of-bounds memory access and potential
crashes.

[How]
Add proper bounds checking using ternary operators to guard all
num_clk_values-1 array accesses. When num_clk_values is 0, return 0
as fallback value instead of accessing invalid memory. This prevents
buffer overflows while maintaining backward compatibility and provides
sensible default behavior for empty clock tables.

Reviewed-by: Dillon Varone 
Signed-off-by: Gabe Teeger 
Signed-off-by: Chuanyu Tseng 
Signed-off-by: Alex Deucher