[PATCH 4/6] Documentation/gpu: How to collect DTN log
From: Rodrigo Siqueira <hidden>
Date: 2021-11-25 15:41:45
Also in:
amd-gfx, dri-devel
Subsystem:
documentation, drm drivers, drm drivers and misc gpu patches, the rest · Maintainers:
Jonathan Corbet, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds
Introduce how to collect DTN log from debugfs. Signed-off-by: Rodrigo Siqueira <redacted> --- Documentation/gpu/amdgpu-dc/amdgpu-dc-debug.rst | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/Documentation/gpu/amdgpu-dc/amdgpu-dc-debug.rst b/Documentation/gpu/amdgpu-dc/amdgpu-dc-debug.rst
index 6dbd21f7f59e..40c55a618918 100644
--- a/Documentation/gpu/amdgpu-dc/amdgpu-dc-debug.rst
+++ b/Documentation/gpu/amdgpu-dc/amdgpu-dc-debug.rst@@ -58,3 +58,20 @@ In this case, if you have a pipe split, you will see one small red bar at the bottom of the display covering the entire display width and another bar covering the second pipe. In other words, you will see a bit high bar in the second pipe. + +DTN Debug +========= + +DC (DCN) provides an extensive log that dumps multiple details from our +hardware configuration. Via debugfs, you can capture those status values by +using Display Test Next (DTN) log, which can be captured via debugfs by using:: + + cat /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log + +Since this log is updated accordingly with DCN status, you can also follow the +change in real-time by using something like:: + + sudo watch -d cat /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log + +When reporting a bug related to DC, consider attaching this log before and +after you reproduce the bug.
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2.25.1