drm/i915: Avoid use of uninitialised values when disabling panel-fitter

We were passing garbage values into the panel-fitter control register
when disabling it on Ironlake - those values (filter modes and reserved
MBZ bits) would have then be re-used the next time panel-fitting was
enabled.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
1 file changed