[Intel-gfx] [PATCH] drm/i915: get runtime PM reference around GEM set_tiling IOCTL

[Chris Wilson]

On Mon, Nov 09, 2015 at 08:16:26PM +0200, Imre Deak wrote:
> After fixing the same issue in the set_caching IOCTL and Chris' request
> to check out the possibilities for an improved RPM ref handling I
> noticed that we have the same issue in the set_tiling IOCTL. Fix this
> up.I didn't see any bug reports about this one, but the GTT unbind
> operation on this path accesses the HW, which needs the ref.
> 
> Signed-off-by: Imre Deak <imre.deak at intel.com>

The reason why we haven't seen a bug report is that we don't get the GTT
mismatch on gen4+ devices (i.e. those with runtime pm). However, for the
sake of completeness, it is better to wrap all the GGTT unbind access in
the rpm reference (and future patches to reduce the wakelock will be
more consistent).

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

-- 
Chris Wilson, Intel Open Source Technology Centre