From 8665bd53f2f2e27e5511d90428cb3f60e6d0ce15 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 20:50:12 +0200 Subject: Merging upstream version 6.8.9. Signed-off-by: Daniel Baumann --- Documentation/gpu/amdgpu/display/dc-debug.rst | 41 +++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'Documentation/gpu/amdgpu/display/dc-debug.rst') diff --git a/Documentation/gpu/amdgpu/display/dc-debug.rst b/Documentation/gpu/amdgpu/display/dc-debug.rst index 40c55a6189..817631b1db 100644 --- a/Documentation/gpu/amdgpu/display/dc-debug.rst +++ b/Documentation/gpu/amdgpu/display/dc-debug.rst @@ -75,3 +75,44 @@ change in real-time by using something like:: When reporting a bug related to DC, consider attaching this log before and after you reproduce the bug. + +DMUB Firmware Debug +=================== + +Sometimes, dmesg logs aren't enough. This is especially true if a feature is +implemented primarily in DMUB firmware. In such cases, all we see in dmesg when +an issue arises is some generic timeout error. So, to get more relevant +information, we can trace DMUB commands by enabling the relevant bits in +`amdgpu_dm_dmub_trace_mask`. + +Currently, we support the tracing of the following groups: + +Trace Groups +------------ + +.. csv-table:: + :header-rows: 1 + :widths: 1, 1 + :file: ./trace-groups-table.csv + +**Note: Not all ASICs support all of the listed trace groups** + +So, to enable just PSR tracing you can use the following command:: + + # echo 0x8020 > /sys/kernel/debug/dri/0/amdgpu_dm_dmub_trace_mask + +Then, you need to enable logging trace events to the buffer, which you can do +using the following:: + + # echo 1 > /sys/kernel/debug/dri/0/amdgpu_dm_dmcub_trace_event_en + +Lastly, after you are able to reproduce the issue you are trying to debug, +you can disable tracing and read the trace log by using the following:: + + # echo 0 > /sys/kernel/debug/dri/0/amdgpu_dm_dmcub_trace_event_en + # cat /sys/kernel/debug/dri/0/amdgpu_dm_dmub_tracebuffer + +So, when reporting bugs related to features such as PSR and ABM, consider +enabling the relevant bits in the mask before reproducing the issue and +attach the log that you obtain from the trace buffer in any bug reports that you +create. -- cgit v1.2.3