[PATCH v4 1/3] drm: Introduce device wedged event

[Lucas De Marchi]

On Sat, Sep 07, 2024 at 08:38:30PM GMT, Asahi Lina wrote:
>
>
>On 9/6/24 6:42 PM, Raag Jadav wrote:
>> Introduce device wedged event, which will notify userspace of wedged
>> (hanged/unusable) state of the DRM device through a uevent. This is
>> useful especially in cases where the device is in unrecoverable state
>> and requires userspace intervention for recovery.
>>
>> Purpose of this implementation is to be vendor agnostic. Userspace
>> consumers (sysadmin) can define udev rules to parse this event and
>> take respective action to recover the device.
>>
>> Consumer expectations:
>> ----------------------
>> 1) Unbind driver
>> 2) Reset bus device
>> 3) Re-bind driver
>
>Is this supposed to be normative? For drm/asahi we have a "wedged"
>concept (firmware crashed), but the only possible recovery action is a
>full system reboot (which might still be desirable to allow userspace to
>trigger automatically in some scenarios) since there is no bus-level
>reset and no firmware reload possible.

maybe let drivers hint possible/supported recovery mechanisms and then
sysadmin chooses what to do?

Lucas De Marchi