[Intel-gfx] [PATCH] drm/i915: Enable FBC for non X-tiled FBs

[Praveen Paneri]

FBC is only enabled for X-tiled framebuffers but there are
quite a few cases where we tend to use Y-tiled framebuffers.
So enabling it for non X-tiled framebuffers.

Signed-off-by: Praveen Paneri <praveen.paneri at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  | 2 ++
 drivers/gpu/drm/i915/intel_fbc.c | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index cc843f9..9d7a376 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2506,6 +2506,8 @@ enum skl_disp_power_wells {
 #define  BDW_FBC_COMPRESSION_MASK	0xfff
 
 #define FBC_LL_SIZE		(1536)
+#define FBC_YSTRIDE		_MMIO(0x4208c)
+#define   FBC_STRIDE_OVERRIDE	(1<<13)
 
 #define FBC_LLC_READ_CTRL	_MMIO(0x9044)
 #define   FBC_LLC_FULLY_OPEN	(1<<30)
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 17d418b..0ac9889 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -301,6 +301,14 @@ static void gen7_fbc_activate(struct drm_i915_private *dev_priv)
 	u32 dpfc_ctl;
 	int threshold = dev_priv->fbc.threshold;
 
+	if (INTEL_GEN(dev_priv) >= 9 &&
+	    i915_gem_object_get_tiling(cache->vma->obj) != I915_TILING_X) {
+		struct intel_fbc_state_cache *cache = &dev_priv->fbc.state_cache;
+		int cfb_stride = DIV_ROUND_UP(cache->plane.src_w,
+					      (32 * threshold)) * 8;
+		I915_WRITE(FBC_YSTRIDE, FBC_STRIDE_OVERRIDE | cfb_stride);
+	}
+
 	dpfc_ctl = 0;
 	if (IS_IVYBRIDGE(dev_priv))
 		dpfc_ctl |= IVB_DPFC_CTL_PLANE(params->crtc.plane);
-- 
1.9.1