[Intel-gfx] [PATCH 4/4] drm/i915/cnl: Apply large line width optimization

[Rodrigo Vivi]

This bit enables hardware that will change the approximation used for distances
calculations for AA wide lines so that they are rendered more accurately.

The default value for this bit leaves the legacy behavior. There is no good
reason to not enable the new approximation except if comparing to previous GEN
rendered images.

v2: Rebase

Signed-off-by: Ben Widawsky <benjamin.widawsky at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h | 1 +
 drivers/gpu/drm/i915/intel_pm.c | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2999a2b..78af798 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2310,6 +2310,7 @@ enum skl_disp_power_wells {
 # define _3D_CHICKEN2_WM_READ_PIPELINED			(1 << 14)
 #define _3D_CHICKEN3	_MMIO(0x2090)
 #define  _3D_CHICKEN_SF_DISABLE_OBJEND_CULL		(1 << 10)
+#define  _3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE	(1 << 5)
 #define  _3D_CHICKEN3_SF_DISABLE_FASTCLIP_CULL		(1 << 5)
 #define  _3D_CHICKEN_SDE_LIMIT_FIFO_POLY_DEPTH(x)	((x)<<1) /* gen8+ */
 #define  _3D_CHICKEN3_SF_DISABLE_PIPELINED_ATTR_FETCH	(1 << 1) /* gen6 */
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index df1b608..5d5df2b 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -8230,6 +8230,9 @@ static void cannonlake_init_clock_gating(struct drm_i915_private *dev_priv)
 {
 	gen9_init_clock_gating(dev_priv);
 
+	I915_WRITE(_3D_CHICKEN3,
+		   _MASKED_BIT_ENABLE(_3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE));
+
 	/* WaFbcNukeOnHostModify:cnl */
 	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
 		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
-- 
1.9.1