[PATCH v2 2/3] drm/doc: Add a section about "App information" for the wedge API

[Raag Jadav]

On Sun, May 11, 2025 at 07:47:44PM -0300, André Almeida wrote:
> Add a section about "App information" for the wedge API.
> 
> Signed-off-by: André Almeida <andrealmeid at igalia.com>
> ---
>  Documentation/gpu/drm-uapi.rst | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
> index 69f72e71a96e..826abe265a24 100644
> --- a/Documentation/gpu/drm-uapi.rst
> +++ b/Documentation/gpu/drm-uapi.rst
> @@ -446,6 +446,21 @@ 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) caused the device to get in the

I'm wondering if we should change the wording to "application involved in device
wedging", or can we guarantee it to be the cause?

My limited understanding is that we'd still need the full dump to find the cause,
if it's possible to also note here.

Raag

> +wedge state 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 not available, the uevent will display as ``PID=-1`` and
> +``APP=none``. Otherwise, ``PID`` and ``APP`` will advertise about the guilty
> +app.
> +
> +The reliability of this information is driver and hardware specific, and should
> +be taken with a caution regarding it's precision.
> +
>  Consumer prerequisites
>  ----------------------
>  
> -- 
> 2.49.0
>