kernel/drivers/gpu/drm/amd/display/dc/bios/command_table.c, branch master

drm/amd/display: Initialize DAC in DCE link encoder using VBIOS

2026-02-19T17:16:12Z

The VBIOS DAC1EncoderControl() function can initialize the DAC, by writing board-specific values to certain registers. Call this at link encoder hardware initialization time similarly to how the equivalent UNIPHYTransmitterControl initialization is done. This fixes DAC output on the Radeon HD 7790. Also remove the ENCODER_CONTROL_SETUP enum from the dac_encoder_control_prepare_params function which is actually not a supported operation for DAC encoders. Fixes: 0fbe321a93ce ("drm/amd/display: Implement DCE analog link encoders (v2)") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Suggested-by: Alex Deucher Reviewed-by: Alex Hung Signed-off-by: Alex Deucher

drm/amd/display: Add missing encoder setup to DACnEncoderControl

2026-01-05T22:00:00Z

Apparently the DAC encoder needs to be set up before use. The BIOS parser in DC did not support this so I assumed it was not necessary, but the DAC doesn't work without it on some GPUs. Fixes: 69b29b894660 ("drm/amd/display: Hook up DAC to bios_parser_encoder_control") Reviewed-by: Alex Deucher Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher

drm/amd/display: Correct color depth for SelectCRTC_Source

2026-01-05T22:00:00Z

Pass the correct enum values as expected by the VBIOS. Previously the actual bit depth integer value was passed, which was a mistake. Fixes: 7fb4f254c8eb ("drm/amd/display: Add SelectCRTC_Source to BIOS parser") Reviewed-by: Alex Deucher Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher

drm/amd/display: Add DAC_LoadDetection to BIOS parser (v2)

2025-10-28T14:09:55Z

DAC_LoadDetection can be used to determine whether something is connected to an analog connector by determining if there is an analog load. This causes visible flickering on displays, so we only resort to using this when the connected display doesn't have an EDID. For reference, see the legacy display code: amdgpu_atombios_encoder_dac_load_detect v2: Only clear corresponding bit from BIOS_SCRATCH_0. Signed-off-by: Timur Kristóf Reviewed-by: Harry Wentland Signed-off-by: Alex Deucher

drm/amd/display: Add SelectCRTC_Source to BIOS parser

2025-10-28T14:08:24Z

The SelectCRTC_Source command will be used to change which CRTC should be connected to which encoder. For reference, see the legacy display code: amdgpu_atombios_encoder_set_crtc_source Signed-off-by: Timur Kristóf Reviewed-by: Harry Wentland Signed-off-by: Alex Deucher

drm/amd/display: Fix fractional fb divider in set_pixel_clock_v3

2025-08-18T22:00:34Z

For later VBIOS versions, the fractional feedback divider is calculated as the remainder of dividing the feedback divider by a factor, which is set to 1000000. For reference, see: - calculate_fb_and_fractional_fb_divider - calc_pll_max_vco_construct However, in case of old VBIOS versions that have set_pixel_clock_v3, they only have 1 byte available for the fractional feedback divider, and it's expected to be set to the remainder from dividing the feedback divider by 10. For reference see the legacy display code: - amdgpu_pll_compute - amdgpu_atombios_crtc_program_pll This commit fixes set_pixel_clock_v3 by dividing the fractional feedback divider passed to the function by 100000. Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") Signed-off-by: Timur Kristóf Acked-by: Alex Deucher Reviewed-by: Rodrigo Siqueira Reviewed-by: Alex Hung Signed-off-by: Alex Deucher (cherry picked from commit 027e7acc7e17802ebf28e1edb88a404836ad50d6) Cc: stable@vger.kernel.org

drm/amd/display: Fix uninitialized variables in DC

2024-04-26T21:22:44Z

This fixes 29 UNINIT issues reported by Coverity. Reviewed-by: Hersen Wu Acked-by: Wayne Lin Signed-off-by: Alex Hung Signed-off-by: Alex Deucher

drm/amdgpu: check PS, WS index

2024-01-15T23:35:37Z

Theoretically, it would be possible for a buggy or malicious VBIOS to overwrite past the bounds of the passed parameters (or its own workspace); add bounds checking to prevent this from happening. Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3093 Signed-off-by: Alexander Richards Signed-off-by: Alex Deucher

drm/amd/display: Fix USBC link creation

2022-06-03T20:43:38Z

[Description] Add USBC connector ID to align with new VBIOS parsing. Add seperate DCN321 link encoder due to different PHY version affecting DP ALT related registers. Signed-off-by: Dillon Varone Acked-by: Jerry Zuo Signed-off-by: Alex Deucher

drm/amd/display: Add support for USBC connector

2022-04-01T03:05:53Z

[Why] Add support for CONNECTOR_ID_USBC Reviewed-by: Alvin Lee Acked-by: Alex Hung Signed-off-by: Samson Tam Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher