drm/doc: Add a section about "Task information" for the wedge API

Add a section about "Task information" for the wedge API.

Reviewed-by: Krzysztof Karas <[email protected]>
Reviewed-by: Raag Jadav <[email protected]>
Reviewed-by: Christian König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: André Almeida <[email protected]>

Author: andrealmeid

Documentation/gpu/drm-uapi.rst

@@ -446,6 +446,23 @@ telemetry information (devcoredump, syslog). This is useful because the first
 hang is usually the most critical one which can result in consequential hangs or
 complete wedging.
 
+Task information
+---------------
+
+The information about which application (if any) was involved in the device
+wedging is useful for userspace if they want to notify the user about what
+happened (e.g. the compositor display a message to the user "The <task name>
+caused a graphical error and the system recovered") or to implement policies
+(e.g. the daemon may "ban" an task that keeps resetting the device). If the task
+information is available, the uevent will display as ``PID=<pid>`` and
+``TASK=<task name>``. Otherwise, ``PID`` and ``TASK`` will not appear in the
+event string.
+
+The reliability of this information is driver and hardware specific, and should
+be taken with a caution regarding it's precision. To have a big picture of what
+really happened, the devcoredump file provides should have much more detailed
+information about the device state and about the event.
+
 Consumer prerequisites
 ----------------------