kernel/linux.git/drivers/gpu/drm/amd/display/dc/link, branch v6.19.12

drm/amd/display: Don't disable DPCD mst_en if sink connected

2026-03-04T12:19:54+00:00

[ Upstream commit 9aeb31b2456452257ad1ff7ec566f21bab1f3e8a ] [WHY] User may connect mst dock with multi monitors and do quick unplug and plug in one of the monitor. This operatioin may create CSN from dock to display driver. Then display driver would disable and then enable mst link and also disable/enable DPCD mst_en bit in dock RX. However, when mst_en bit being disabled, if dock has another CSN message to transmit then the message would be removed because of the disabling of mst_en. In this case, the message is missing and it ends up no display in the replugged monitor. [HOW] Don't disable mst_en bit when link still has sink connected. Reviewed-by: Wenjing Liu Signed-off-by: Peichen Huang Signed-off-by: Chenyu Chen Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Correct FIXED_VS Link Rate Toggle Condition

2026-03-04T12:19:51+00:00

[ Upstream commit 531fe6e0fee85a1bdb5b8223a706fff654ed0a61 ] [WHY&HOW] The condition is only perform toggle if FIXED_VS LTTPR reports no IEEE OUI. The literal "\x0,\x0,\x0" contains commas changes the bytes being compared to {0x00,0x2C,0X00}. The correct literal should be "\x00\x00\x00" without commas. Reviewed-by: Charlene Liu Reviewed-by: Wenjing Liu Signed-off-by: Jing Zhou Signed-off-by: Roman Li Tested-by: Dan Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Correct DSC padding accounting

2026-03-04T12:19:51+00:00

[ Upstream commit c7062be3380cb20c8b1c4a935a13f1848ead0719 ] [WHY] - After the addition of all OVT patches, DSC padding was being accounted for multiple times, effectively doubling the padding - This caused compliance failures or corruption [HOW] - Add padding to DSC pic width when required by HW, and do not re-add when calculating reg values - Do not add padding when computing PPS values, and instead track padding separately to add when calculating slice width values Reviewed-by: Chris Park Reviewed-by: Wenjing Liu Signed-off-by: Relja Vojvodic Signed-off-by: Alex Hung Tested-by: Dan Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Enable DAC in DCE link encoder

2026-02-26T23:01:38+00:00

[ Upstream commit 4bd8b5f8bcb57b430c35494d8a2471ce5fd7661d ] Ensure that the DAC output is enabled at the correct time by moving it to the DCE link encoder similarly to how digital outputs are enabled. This also removes the call to DAC1EncoderControl from the DCE HWSS, which always felt like it was a hacky solution. Fixes: 0fbe321a93ce ("drm/amd/display: Implement DCE analog link encoders (v2)") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Reviewed-by: Alex Hung Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Don't call find_analog_engine() twice

2026-02-26T23:01:38+00:00

[ Upstream commit 613b1737abe1bd0a65b49851e777231302095e28 ] The analog engine is already there in the link_analog_engine variable and assigned to enc_init_data.analog_engine already. I suspect this was a rebase mistake. Fixes: 436d0d22aa70 ("drm/amd/display: Pass proper DAC encoder ID to VBIOS") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Reviewed-by: Alex Hung Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Don't repeat DAC load detection

2026-02-26T23:00:58+00:00

[ Upstream commit 0d89268d20c961b6226a4aa948fdbe9f93021d95 ] The analog link detection code path had already performed the DAC load detection by the time the EDID read is attempted. So there is no need to repeat the DAC load detection, we can know that no display is connected if no EDID is read. Fixes: ac1bb4952267 ("drm/amd/display: Use DAC load detection on analog connectors (v2)") Suggested-by: Alex Hung Reviewed-by: Alex Deucher Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Update dc_connection_dac_load to dc_connection_analog_load

2026-02-26T23:00:58+00:00

[ Upstream commit 57c8690a84bec025a8bc22e5f867fd660c4a3e76 ] Update to a more accurate name dc_connection_analog_load. Reviewed-by: Harry Wentland Signed-off-by: Alex Hung Signed-off-by: Chenyu Chen Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Stable-dep-of: 0d89268d20c9 ("drm/amd/display: Don't repeat DAC load detection") Signed-off-by: Sasha Levin

drm/amd/display: Pass proper DAC encoder ID to VBIOS

2026-02-26T23:00:58+00:00

[ Upstream commit 436d0d22aa7035a9f9b24fb14cd0e84d6571ea87 ] Similarly to the analog_engine field, add a new analog_id field which contains the encoder ID of the analog encoder that corresponds to the link encoder. Previously, the default encoder ID of the link encoder was used, which meant that we passed the wrong ID in case of DVI-I. Fixes: 5834c33fd3f6 ("drm/amd/display: Add concept of analog encoders (v2)") Reviewed-by: Alex Deucher Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amd/display: Use local variable for analog_engine initialization

2026-02-26T23:00:58+00:00

[ Upstream commit 6afc422e1a49d18b63f7042fb1cb6f519a972c8a ] [Why&How] Use local variable for analog_engine retrieval and check if it is supported instead of the struct parameter. Signed-off-by: Ivan Lipski Reviewed-by: Harry Wentland Tested-by: Dan Wheeler Signed-off-by: Alex Deucher Stable-dep-of: 436d0d22aa70 ("drm/amd/display: Pass proper DAC encoder ID to VBIOS") Signed-off-by: Sasha Levin

drm/amd/display: Remove unused encoder types

2026-02-26T23:00:58+00:00

[ Upstream commit 4ab27b01df629545de5a5f9889867b0f19438cd8 ] [Why&How] We only support ENCODER_ID_INTERNAL_UNIPHY encoders now, so NUTMEG & TRAVIS can be removed from translate_encoder_to_transmitter. Also refactor to use local variables of transmitter to exit early. V2: Fix construct_phy check for TRANSMITTER_UKNOWN Signed-off-by: Ivan Lipski Reviewed-by: Harry Wentland Tested-by: Dan Wheeler Signed-off-by: Alex Deucher Stable-dep-of: 436d0d22aa70 ("drm/amd/display: Pass proper DAC encoder ID to VBIOS") Signed-off-by: Sasha Levin