https://bugzilla.kernel.org/show_bug.cgi?id=214199 --- Comment #2 from Zeljko (kernel@xxxxxxxxxxxxxxxxxxx) --- At first, I've got both monitors to work correctly with amdgpu.dc=0 kernel parameter. After analyzing the dmesg outputs without the above kernel parameter I've noticed that, on boot, my second monitor (connected on HDMI-A-2) was detected but went on some kind of loop reporting that the Edid was changed. [drm:dc_link_detect_helper [amdgpu]] link=3, dc_sink_in=0000000000000000 is now Disconnected prev_sink=000000009ae23fd3 dpcd same=1 edid same=0 [drm:amdgpu_dm_update_connector_after_detect [amdgpu]] DCHPD: connector_id=3: Old sink=000000009ae23fd3 New sink=0000000000000000 [drm:drm_connector_update_edid_property [drm]] [CONNECTOR:79:HDMI-A-2] Edid was changed. [drm:drm_connector_update_edid_property [drm]] Updating change counter to 61 Same thing happens when the computer wakes up from suspend, but than both monitors go into the same kind of loop. [drm:dc_link_detect_helper [amdgpu]] link=3, dc_sink_in=0000000000000000 is now Disconnected prev_sink=000000003f9f81c9 dpcd same=1 edid same=0 [drm:amdgpu_dm_update_connector_after_detect [amdgpu]] DCHPD: connector_id=3: Old sink=000000003f9f81c9 New sink=0000000000000000 [drm:drm_connector_update_edid_property [drm]] [CONNECTOR:79:HDMI-A-2] Edid was changed. [drm:drm_connector_update_edid_property [drm]] Updating change counter to 118 [drm:dc_link_detect_helper [amdgpu]] link=2, dc_sink_in=0000000000000000 is now Disconnected prev_sink=000000006f240528 dpcd same=1 edid same=0 [drm:amdgpu_dm_update_connector_after_detect [amdgpu]] DCHPD: connector_id=2: Old sink=000000006f240528 New sink=0000000000000000 [drm:drm_connector_update_edid_property [drm]] [CONNECTOR:74:HDMI-A-1] Edid was changed. [drm:drm_connector_update_edid_property [drm]] Updating change counter to 41 After some googling I've managed to get both monitors working correctly without amdgpu.dc=0 by forcing edid files extracted from both monitors using these kernel parameters: video=HDMI-A-1:e video=HDMI-A-2:e drm.edid_firmware=HDMI-A-1:edid/edid1.bin,HDMI-A-2:edid/edid2.bin Couple more details that may help: - both monitors are the same model BenQ GW2470 - they are both connected via a HDMI 2.0 cable from the same maker and are the same length - I've decoded and compared both edid files and the only differences are the "Display Product Serial Number" and "Checksum" -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
