[Intel-gfx] [PATCH v5] drm/i915: Fix FBC cfb stride programming for non X-tiled FB

[Praveen Paneri]

When FBC is enabled for linear, legacy Y-tiled and Yf-tiled
surfaces on gen9, the cfb stride must be programmed by SW as

cfb_stride = ceiling[(at least plane width in pixels)/
		     (32 * compression limit factor)] * 8

v2: Minor fix for a build error
v3: Fixed subject, register name and platform check (Ville)
v4: Added WA details in comment (Paulo)
v5:
 - Read modified reg write to preserve other bit values (Paulo)
 - Store modified stride value in reg_params (Paulo)
 - Keep GLK out of the WA (Paulo)

Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Praveen Paneri <praveen.paneri at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  |  3 +++
 drivers/gpu/drm/i915/intel_fbc.c | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c712d01..9e65f34 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6710,6 +6710,9 @@ enum {
 #define CHICKEN_MISC_2		_MMIO(0x42084)
 #define  COMP_PWR_DOWN		(1 << 23)
 
+#define CHICKEN_MISC_4		_MMIO(0x4208c)
+#define   FBC_STRIDE_OVERRIDE	(1<<13)
+
 #define _CHICKEN_PIPESL_1_A	0x420b0
 #define _CHICKEN_PIPESL_1_B	0x420b4
 #define  HSW_FBCQ_DIS			(1 << 22)
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 860b8c2..251d3f4 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -288,9 +288,28 @@ static bool ilk_fbc_is_active(struct drm_i915_private *dev_priv)
 static void gen7_fbc_activate(struct drm_i915_private *dev_priv)
 {
 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
+	struct intel_fbc_state_cache *cache = &dev_priv->fbc.state_cache;
 	u32 dpfc_ctl;
 	int threshold = dev_priv->fbc.threshold;
 
+	/* Display WA #0529: skl, kbl, bxt but not for glk*/
+	if (IS_GEN9(dev_priv) && !IS_GEMINILAKE(dev_priv)) {
+		u32 chicken_misc4 = I915_READ(CHICKEN_MISC_4);
+
+		if (i915_gem_object_get_tiling(cache->vma->obj)
+				!= I915_TILING_X) {
+			int cfb_stride = DIV_ROUND_UP(cache->plane.src_w,
+					 (32 * threshold)) * 8;
+			params->fb.stride = cfb_stride;
+
+			I915_WRITE(CHICKEN_MISC_4, chicken_misc4 |
+					FBC_STRIDE_OVERRIDE | cfb_stride);
+		} else {
+			I915_WRITE(CHICKEN_MISC_4, chicken_misc4 &
+					~FBC_STRIDE_OVERRIDE);
+		}
+	}
+
 	dpfc_ctl = 0;
 	if (IS_IVYBRIDGE(dev_priv))
 		dpfc_ctl |= IVB_DPFC_CTL_PLANE(params->crtc.plane);
-- 
1.9.1