[Intel-gfx] [PATCH 1/3] drm/i915: Always sanity check engine state upon idling

[Chris Wilson]

Quoting Chris Wilson (2017-08-26 12:09:33)
> When we do a locked idle we know that afterwards all requests have been
> completed and the engines have been cleared of tasks. For whatever
> reason, this doesn't always happen and we may go into a suspend with
> ELSP still full, and this causes an issue upon resume as we get very,
> very confused.
> 
> If the engines refuse to idle, mark the device as wedged. In the process
> we get rid of the maybe unused open-coded version of wait_for_engines
> reported by Nick Desaulniers and Matthias Kaehlcke.
> 
> References: https://bugs.freedesktop.org/show_bug.cgi?id=101891
References: https://bugs.freedesktop.org/show_bug.cgi?id=102456

> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Matthias Kaehlcke <mka at chromium.org>