[Intel-gfx] [PATCH 3/3] drm/i915/execlists: Reset CSB pointers on canceling requests (wedging)

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> The prior assumption was that we did not need to reset the CSB on
> wedging when cancelling the outstanding requests as it would be cleaned
> up in the subsequent reset prior to restarting the GPU. However, what
> was not accounted for was that in performing the reset, we would try to

'performing the reset' could be 'preparing engine for reset'

> process the outstanding CSB entries. If the GPU happened to complete a
> CS event just as we were performing the cancellation of requests, that
> event would be kept in the CSB until the reset -- but our bookkeeping
> was cleared, causing confusion when trying to complete the CS event.
>
> v2: Use a sanitize on unwedge to avoid interfering with eio suspend
> (where we intentionally disable GPU reset).
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107925
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

I was glad to notice that there were quality comments
on resetting/clearing the csb/ports.

Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>