[PATCH v3 2/3] drm/doc: Add a section about "App information" for the wedge API

[André Almeida]

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

Signed-off-by: André Almeida <andrealmeid at igalia.com>
---
v3:
 - Change "app that caused ..." to "app involved ..."
 - Clarify that devcoredump have more information about what happened
 - Update that PID and APP will be empty if there's no app info
---
 Documentation/gpu/drm-uapi.rst | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
index 69f72e71a96e..3300a928d8ef 100644
--- a/Documentation/gpu/drm-uapi.rst
+++ b/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.
 
+App 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 <app name>
+caused a graphical error and the system recovered") or to implement policies
+(e.g. the daemon may "ban" an app that keeps resetting the device). If the app
+information is available, the uevent will display as ``PID=<pid>`` and
+``APP=<task name>``. Otherwise, ``PID`` and ``APP`` 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
+happened, the devcoredump file provides should have much more detailed
+information about the device state and about the event.
+
 Consumer prerequisites
 ----------------------
 
-- 
2.49.0