[Intel-gfx] [PATCH 18/66] drm/i915: Always defer fenced work to the worker

[Chris Wilson]

Quoting Thomas Hellström (Intel) (2020-07-31 10:03:59)
> 
> On 7/15/20 1:50 PM, Chris Wilson wrote:
> > Currently, if an error is raised we always call the cleanup locally
> > [and skip the main work callback]. However, some future users
> Could you add an example of those future users?

In the next (or two) patch, the code needs to do the error cleanup from
process context. Since the error paths should be relatively infrequent,
and more often than not raised synchronously, I didn't see a reason to
build in a flag to say whether or not the release-on-error could be
performed immediately from the interrupt context.

The example in this series is that even if an error is thrown, we have
committed changes to the ppGTT layout (in particular marking PTE to be
evicted) and so we must complete unbinding the old pages from the ppGTT,
otherwise they may remain accessible.
-Chris