drm/i915: fix FBC for cases where crtc->base.y is non-zero

I only tested this on BDW and SKL, but since the register description
is the same ever since gen4, let's assume that all gens take the same
register format. If that's not true, then hopefully someone will
bisect a bug to this patch and we'll fix it.

Notice that the wrong fence offset register just means that the
hardware tracking will be wrong.

Testcases:
 - igt/kms_frontbuffer_tracking/fbc-1p-primscrn-pri-shrfb-draw-mmap-gtt
 - igt/kms_frontbuffer_tracking/fbc-2p-primscrn-pri-shrfb-draw-mmap-gtt

v2:
  - Add intel_crtc->adjusted_{x,y} so this code can work independently
    of intel_gen4_compute_page_offset(). (Ville).
  - This version also works on SKL.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 394018ead36b..ab3c29639857 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -537,6 +537,8 @@ struct intel_crtc {
 	 * gen4+ this only adjusts up to a tile, offsets within a tile are
 	 * handled in the hw itself (with the TILEOFF register). */
 	unsigned long dspaddr_offset;
+	int adjusted_x;
+	int adjusted_y;
 
 	struct drm_i915_gem_object *cursor_bo;
 	uint32_t cursor_addr;