kernel/drivers/gpu/drm/amd/display/dc/dio, branch linux-rolling-stable

drm/amd/display: Add USB-C DP Alt Mode lane limitation in DCN32

2026-03-04T12:19:49Z

[ Upstream commit cea573a8e1ed83840a2173d153dd68e172849d44 ] [Why] USB-C DisplayPort Alt Mode with concurrent USB data needs lane count limitation to prevent incorrect 4-lane DP configuration when only 2 lanes are available due to hardware lane sharing between DP and USB3. [How] Query DMUB for Alt Mode status (is_dp_alt_disable, is_usb, is_dp4) in dcn32_link_encoder_get_max_link_cap() and cap DP to 2 lanes when USB is active on USB-C port. Added inline documentation explaining the USB-C lane sharing constraint. Reviewed-by: PeiChen Huang Signed-off-by: LinCheng Ku Signed-off-by: Chenyu Chen Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Rename header file link.h to link_service.h

2025-09-15T20:57:29Z

[WHY] Header file name "link.h" collides with system header when dc is compiled as a user-mode library [WHAT] Rename link.h to link_service.h to avoid name collision Reviewed-by: Alvin Lee Signed-off-by: Wesley Chalmers Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Remove redundant ternary operators

2025-09-05T21:38:39Z

For ternary operators in the form of "a ? true : false" or "a ? false : true", if 'a' itself returns a boolean result, the ternary operator can be omitted. Remove redundant ternary operators to clean up the code. Signed-off-by: Liao Yuanhong Signed-off-by: Alex Deucher

drm/amd/display: misc for dio encoder refactor

2025-03-05T15:39:20Z

[WHY] These are left required changes for dio encoder refactor. [HOW] 1. original logic is separated by config option 2. new link encoder dp enable/disable code for dcn35 3. process fec only for DP 8b10b encoding Reviewed-by: Cruise Hung Signed-off-by: Peichen Huang Signed-off-by: Wayne Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Refactor DCN4x and related code

2025-02-25T16:44:02Z

[why & how] Refactor existing code related to DCN4x for better code sharing with other modules. Reviewed-by: Charlene Liu Signed-off-by: Swapnil Patel Signed-off-by: Zaeem Mohamed Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Fix BT2020 YCbCr limited/full range input

2025-02-19T20:14:10Z

[Why] BT2020 YCbCr input is not handled properly when full range quantization is used and limited range is not supported at all. [How] - Add enums for BT2020 YCbCr limited/full range - Add limited range CSC matrix Reviewed-by: Krunoslav Kovac Signed-off-by: Ilya Bakoulin Signed-off-by: Roman Li Tested-by: Robert Mader Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Allow reuse of of DCN4x code

2025-02-13T02:03:01Z

Remove the static qualifier to make it available for code sharing with other components. Reviewed-by: Charlene Liu Signed-off-by: Dmytro Signed-off-by: Charlene Liu Signed-off-by: Alex Hung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: improve dpia pre-train

2025-01-10T17:12:29Z

[WHY] We see unstable DP LL 4.2.1.3 test result with dpia pre-train. It is because the outbox interrupt mechanism can not handle HPD immediately and require some improvement. [HOW] 1. not enable link if hpd_pending is true. 2. abort pre-train if training failed and hpd_pending is true. 3. check if 2 lane supported when it is alt mode Reviewed-by: Wenjing Liu Reviewed-by: Meenakshikumar Somasundaram Signed-off-by: Peichen Huang Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: have pretrain for dpia

2025-01-06T19:44:27Z

[WHY] We like to have pretrain for dpia link so that dp and dp tunneling have aligned behavior. The Main difficult for dpia pretrain is that encoder can not get corresponded dpia port when link detection in current implementation. [HOW] 1. create enable/disable dpia output functions for dcn35 encoder and have dpia_id and other necessary info as inputs. 2. dcn35 dpia use the new functions to enable/disable output. 3. have a option to enable/disable the change. Reviewed-by: Wenjing Liu Reviewed-by: Meenakshikumar Somasundaram Signed-off-by: Peichen Huang Signed-off-by: Roman Li Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher

drm/amd/display: Remove useless assignments and variables

2024-10-28T20:36:13Z

[WHAT & HOW] misc0, temp and split_pipe are assigned but immediately re-assigned to other values. The early assignments are useless and are removed. Unused variables are removed as well. This fixes 5 UNUSED_VALUE issues reported by Coverity. Reviewed-by: Rodrigo Siqueira Signed-off-by: Alex Hung Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher