[Intel-gfx] [PATCH v2 4/4] drm/i915/fbc: Allow FBC + VT-d on SKL/BXT

[Ville Syrjala]

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

With the iommu driver disabling VT-d superpage it should be
safe to use FBC on SKL/BXT with VT-d otherwise enabled.

Cc: David Woodhouse <dwmw2 at infradead.org>
Cc: Lu Baolu <baolu.lu at linux.intel.com>
Cc: iommu at lists.linux-foundation.org
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_fbc.c | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
index 82effb64a3b9..de44f93a33d0 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -1448,19 +1448,6 @@ static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
 	return 0;
 }
 
-static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
-{
-	/* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
-	if (intel_vtd_active() &&
-	    (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
-		drm_info(&dev_priv->drm,
-			 "Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
-		return true;
-	}
-
-	return false;
-}
-
 /**
  * intel_fbc_init - Initialize FBC
  * @dev_priv: the i915 device
@@ -1478,9 +1465,6 @@ void intel_fbc_init(struct drm_i915_private *dev_priv)
 	if (!drm_mm_initialized(&dev_priv->mm.stolen))
 		mkwrite_device_info(dev_priv)->display.has_fbc = false;
 
-	if (need_fbc_vtd_wa(dev_priv))
-		mkwrite_device_info(dev_priv)->display.has_fbc = false;
-
 	dev_priv->params.enable_fbc = intel_sanitize_fbc_option(dev_priv);
 	drm_dbg_kms(&dev_priv->drm, "Sanitized enable_fbc value: %d\n",
 		    dev_priv->params.enable_fbc);
-- 
2.31.1