linux/drivers/gpu/drm/amd/display/dc/dml, branch master

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

2026-03-30T19:12:15Z

[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: Fix Silence signed/unsighed mismatch warning in dc

2026-03-30T18:55:17Z

[Why] Implicit signed-to-unsigned conversions caused compiler warnings in DC paths. [How] Added explicit (unsigned int)/(uint32_t) casts for sentinel -1 assignments and IRQ ~MASK initializers, with small cast alignment in logging/DPCD code. Functionality and behavior is unchanged; only type intent is explicit. Reviewed-by: Dillon Varone Signed-off-by: Gaghik Khachatrian Signed-off-by: Chuanyu Tseng Signed-off-by: Alex Deucher

drm/amd/display: Don't set 4to1MPC config dynamically

2026-03-30T18:52:56Z

We were previously modifying the global dc->config.enable_4to1MPC dynamically. These variables are meant as global configs, not to by dynamically modified. Modifying them dynamically prevents us from enabling/disabling functionality for debug purposes and can easily lead to bad things since we're not operating on the current state but on DC-wide variables. Instead we should look at the existing split4mpc decision in dcn20_validate_apply_split_flags and make the decision there, if the global config.enable_4to1MPC is set to true for the DCN version we're running. This fixes corruption that is observed when running a new IGT kms_colorop test for color-space-conversion that uses a YUV plane and outputs to a writeback connector. Co-developed by Claude Sonnet 4.5. Assisted-by: Claude:claude-sonnet-4.5 Reviewed-by: Nicholas Kazlauskas Signed-off-by: Harry Wentland Signed-off-by: Chuanyu Tseng Signed-off-by: Alex Deucher

drm/amd/display: Should support p-state under dcn21

2026-03-30T18:39:36Z

[Why] Under DCN21, observe flip_done timeout issue while running 3D benchmark under MPO case. Timeout is caused by driver fails validate_bandwidth() during atomic_commit_tail but passes atomic_check. Under further analysis, indicates the delta of atomic_check and atomic_commit_tail are dc->current_state->bw_ctx.dml.soc.sr_exit_time_us and dc->current_state->bw_ctx.dml.soc.sr_enter_plus_exit_time_us. We set validate_mode as DC_VALIDATE_MODE_ONLY while calling dc_validate_global_state() at atomic_check, but set mode as DC_VALIDATE_MODE_AND_PROGRAMMING during atomic_commit_tail. If dc_validate_mode set as DC_VALIDATE_MODE_ONLY, validate_bandwidth() will skip the wm and dlg calculation. During commit_tail, validate_bandwidth() is called with dc_validate_mode set as DC_VALIDATE_MODE_AND_PROGRAMMING and dc_state->bw_ctx.dml.soc.sr_exit_time_us might get modified after the wm_calculation and stored into dc->current_state. Which means dc->current_state->bw_ctx.dml.soc.sr_exit_time_us might not aligned with the one stored in dm_state->context. That causes duplicated dm_state->context not aligned with dc->current_state, and might have bandwidth validation pass in atomic_check and fail in commit_tail later. [How] When the issue occurs, it fails dml_get_voltage_level() with the condition dm_allow_self_refresh_and_mclk_switch but pass with the condition dm_allow_self_refresh. However, we should support p-state. So we should not pass validate_bandwidth by allowing self refresh only. Change the policy under DCN21. Reviewed-by: Nicholas Kazlauskas Signed-off-by: Wayne Lin Signed-off-by: Chuanyu Tseng Signed-off-by: Alex Deucher

drm/amd/display: Silence static analysis warning

2026-03-17T14:35:58Z

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

Revert "drm/amd/display: Add Gfx Base Case For Linear Tiling Handling"

2026-02-19T17:16:11Z

This reverts commit 08a01ec306db ("drm/amd/display: Add Gfx Base Case For Linear Tiling Handling") Reason for revert: Got blank screen issues while doing PNP Reviewed-by: Joshua Aberback Signed-off-by: Nicholas Carbones Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Increase DCN35 SR enter/exit latency

2026-02-12T20:12:26Z

[Why & How] On Framework laptops with DDR5 modules, underflow can be observed. It's unclear why it only occurs on specific desktop contents. However, increasing enter/exit latencies by 3us seems to resolve it. Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4463 Reviewed-by: Nicholas Kazlauskas Signed-off-by: Leo Li Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org

drm/amd/display: Add Gfx Base Case For Linear Tiling Handling

2026-02-03T21:40:10Z

[Why] Post-driver cases always use linear tiling yet there is no dedicated Gfx handling for this condition. [How] Add DcGfxBase/DalGfxBase to gfx version enums and set tiling to linear when it is used. Also, enforce the use of proper tiling format as tiling information is used. Reviewed-by: Dillon Varone Signed-off-by: Nicholas Carbones Signed-off-by: Wayne Lin Tested-by: Dan Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Reduce number of arguments of dcn30's CalculateWatermarksAndDRAMSpeedChangeSupport()

2026-01-05T21:24:06Z

CalculateWatermarksAndDRAMSpeedChangeSupport() has a large number of parameters, which must be passed on the stack. Most of the parameters between the two callsites are the same, so they can be accessed through the existing mode_lib pointer, instead of being passed as explicit arguments. Doing this reduces the stack size of dml30_ModeSupportAndSystemConfigurationFull() from 1912 bytes to 1840 bytes building for x86_64 with clang-22, helping stay under the 2048 byte limit for display_mode_vba_30.c. Additionally, now that there is a pointer to mode_lib->vba available, use 'v' consistently throughout the entire function. Signed-off-by: Nathan Chancellor Signed-off-by: Alex Deucher

drm/amd/display: Reduce number of arguments of dcn30's CalculatePrefetchSchedule()

2026-01-05T21:23:35Z

After an innocuous optimization change in clang-22, dml30_ModeSupportAndSystemConfigurationFull() is over the 2048 byte stack limit for display_mode_vba_30.c. drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.c:3529:6: warning: stack frame size (2096) exceeds limit (2048) in 'dml30_ModeSupportAndSystemConfigurationFull' [-Wframe-larger-than] 3529 | void dml30_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib) | ^ With clang-21, this function was already close to the limit: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.c:3529:6: warning: stack frame size (1912) exceeds limit (1586) in 'dml30_ModeSupportAndSystemConfigurationFull' [-Wframe-larger-than] 3529 | void dml30_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib) | ^ CalculatePrefetchSchedule() has a large number of parameters, which must be passed on the stack. Most of the parameters between the two callsites are the same, so they can be accessed through the existing mode_lib pointer, instead of being passed as explicit arguments. Doing this reduces the stack size of dml30_ModeSupportAndSystemConfigurationFull() from 2096 bytes to 1912 bytes with clang-22. Closes: https://github.com/ClangBuiltLinux/linux/issues/2117 Signed-off-by: Nathan Chancellor Signed-off-by: Alex Deucher