linux-toradex.git/drivers/gpu/drm/amd/display/dc/dml/dcn21, branch master

drm/amd/display: Fix warnings

2026-05-11T20:10:34+00:00

[Why & How]
Fix various warnings related to unsigned/signed mismatches
-  Consistently use the same signedness for a given value
-  Explcitly cast between types when needed

Reviewed-by: Dillon Varone 
Signed-off-by: Clay King 
Signed-off-by: James Lin 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fix multiple compiler warnings

2026-05-11T20:10:30+00:00

[Why]
Unreachable Code;
Copy Constructor Deleted;
Local Declaration Hides Parameter;
Local Declaration Hides Outer Scope;
Uninitialized or Suspicious Memory Use.

[How]
- Removed or refactored unreachable code paths
- Ensured proper copy constructors in C++ classes
- Renamed local variables that shadowed function parameters
- Renamed inner loop/block variables to avoid shadowing outer scope
  Fixed in 8 files across several FPU layers
  Also fixed in color_gamma and cs_funcs modules
- Reordered guard conditions to validate pipe type before accessing stream
- Ensures safe memory access patterns in DC DMUB service layer

All changes maintain backward compatibility and preserve functional behavior.

Reviewed-by: Dillon Varone 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: James Lin 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fix type mismatches in DML and normalize loop bounds

2026-05-05T13:56:52+00:00

[Why]
Address signed/unsigned comparison warnings across DML paths
to keep builds warning-clean and improve type safety at comparison
boundaries. Most warnings came from signed loop/index temporaries compared
against unsigned counters (for example pipe_count, num_states, and
candidate/state counts), plus a small number of mixed signed/unsigned
clock and geometry checks.

[How]
Aligned iterator and temporary variable types with the semantic type
of the compared bounds. Used unsigned indices for loops bounded by unsigned
counters, and retained signed types where values are semantically signed
(for example plane_count math, timing/micro-schedule arithmetic, and
reverse/sentinel-style iteration). Where mixed signed/unsigned comparisons
are intentional, applied explicit boundary casts instead of broad type
changes (for example dispclk minimum clamp and selected timing/height
comparisons).

As a side effect of converting count parameters such as
NumberOfActivePlanes to unsigned, normalized equivalent loop forms from:

for (i = 0; i <= NumberOfActivePlanes - 1; i++)

into the normalized form:

for (i = 0; i < NumberOfActivePlanes; i++)

to keep bound style coherent and avoid avoidable mismatch patterns.

No functional behavior changes are intended; this is a warning-resolution
and type-alignment cleanup.

Assisted-by: Copilot
Reviewed-by: Dillon Varone 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: James Lin 
Signed-off-by: Alex Deucher

drm/amd/display: Fix narrowing boundaries in dml

2026-04-28T18:30:03+00:00

[Why]
DML code paths include implicit integer narrowing at protocol and
storage boundaries. Making these boundaries explicit improves clarity
and reduces warning noise while preserving behavior.

[How]
Apply explicit C-style casts at intentional narrowing boundaries
across DML calculation, mode support, RQ/DLG, wrapper, and DSC
helper paths.
Keep intermediate arithmetic in natural-width types where practical,
with minor type-consistency cleanups where needed. Add explicit
boundary casts for intentional narrowing and keep intermediate math
in wider types where practical, with small type-consistency cleanups
to maintain behavior and readability.

Reviewed-by: Dillon Varone 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: Tom Chung 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Fixed Silence complier warnings in dc

2026-03-30T19:12:15+00:00

[Why]
Resolve compiler warnings by marking unused parameters explicitly.

[How]
In .c and .h function definitions, keep parameter names
in signatures and add a line with `(void)param;` in function body

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

Reviewed-by: Dillon Varone 
Reviewed-by: Austin Zheng 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: Chuanyu Tseng 
Signed-off-by: Alex Deucher

drm/amd/display: Silence static analysis warning

2026-03-17T14:35:58+00:00

Silence static analysis warnings by ensuring swath size temporaries are
initialized before use. No functional change intended.

Reviewed-by: Dillon Varone 
Signed-off-by: Gaghik Khachatrian 
Signed-off-by: Chuanyu Tseng 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Incorrect 'not' operator usage

2025-08-27T17:57:50+00:00

Consolidating multiple CodeQL Fixes for alerts with rule id: cpp/incorrect-not-operator-usage

Reviewed-by: Joshua Aberback 
Signed-off-by: Clay King 
Signed-off-by: Aurabindo Pillai 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Remove redundant assignments

2024-10-07T18:17:05+00:00

[WHAT & HOW]
log2_blk_height and log2_blk_width are assigned to 0 and then
immediately are updated to other values. The assignments to zero are
redudant and removed.

This fixes 18 UNUSED_VALUE issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira 
Signed-off-by: Alex Hung 
Signed-off-by: Rodrigo Siqueira 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Remove unnecessary assignments

2024-10-07T18:16:58+00:00

[WHAT & HOW]
TimeForFetchingMetaPTE, TimeForFetchingRowInVBlank and
LinesToRequestPrefetchPixelData are local variables. They
are freed when CalculatePrefetchSchedule() ends and need
not clearing explicitly.

This fixes 21 UNUSED_VALUE issues reported by Coverity.

Reviewed-by: Nevenko Stupar 
Signed-off-by: Alex Hung 
Signed-off-by: Rodrigo Siqueira 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: Initialize get_bytes_per_element's default to 1

2024-07-27T21:35:44+00:00

Variables, used as denominators and maybe not assigned to other values,
should not be 0. bytes_per_element_y & bytes_per_element_c are
initialized by get_bytes_per_element() which should never return 0.

This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.

Signed-off-by: Alex Hung 
Reviewed-by: Aurabindo Pillai 
Tested-by: Daniel Wheeler 
Signed-off-by: Rodrigo Siqueira 
Signed-off-by: Alex Deucher