[Intel-gfx] [PATCH] drm/i915: Skip CPU synchronisation on dmabuf attachments

[Dongwon Kim]

Acked-by: Dongwon Kim <dongwon.kim at intel.com>

It makes lots of sense to make CPU cache operation done only when
needed. Similar change was already landed in drm-prime and other
vendor specific drivers. We are actually seeing huge performance
boost in a specific customer case where dmabuf was used between
camera driver (importer) and i915 after applying this patch.

Please consider upstreaming this code change.