[Intel-gfx] [PATCH 2/9] drm/i915: Don't set persistent FBC mode on ILK/SNB

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The ILK/SNB docs are a bit unclear what the persistent mode does, but
the CTG docs clearly state that it was meant to be used when we're
tracking back buffer modifications. We never do that, so leave it in
non-persistent mode.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index c9d1b0c..8cea92e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -203,8 +203,6 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc,
 	dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
 	dpfc_ctl &= DPFC_RESERVED;
 	dpfc_ctl |= (plane | DPFC_CTL_LIMIT_1X);
-	/* Set persistent mode for front-buffer rendering, ala X. */
-	dpfc_ctl |= DPFC_CTL_PERSISTENT_MODE;
 	dpfc_ctl |= DPFC_CTL_FENCE_EN;
 	if (IS_GEN5(dev))
 		dpfc_ctl |= obj->fence_reg;
-- 
1.8.3.2