drm/i915: Share the common work of disabling active FBC before updating

Upon review, all path share the same dependencies for updating the
registers and so we can benefit from sharing the code and checking
early.

This removes the unsightly intel_wait_for_vblank() from the lowlevel
functions and upon further analysis the only path that will require a
wait is if we are performing an instantaneous transition between two
valid FBC configurations. The page-flip path itself will have disabled
FBC registers and will have waited for at least one vblank before
finishing the flip and attempting to re-enable FBC. This wait can be
accomplished simply by delaying the enable until after we are sure that
a vblank will have passed, which we are already doing to make sure that
the display is settled before enabling FBC.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3154b3dfd804..00dc59a51ccd 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -331,10 +331,8 @@ typedef struct drm_i915_private {
         uint32_t last_instdone1;
 
         unsigned long cfb_size;
-        unsigned long cfb_pitch;
-        unsigned long cfb_offset;
-        int cfb_fence;
-        int cfb_plane;
+        unsigned int cfb_fb;
+        enum plane cfb_plane;
         int cfb_y;
         struct intel_fbc_work *fbc_work;