Merge remote-tracking branches 'spi/fix/lock', 'spi/fix/maintainers', 'spi/fix/put...

[cascardo/linux.git] / drivers / gpu / drm / i915 / intel_fbc.c

diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 6a7ad3e..3836a1c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -1230,12 +1230,29 @@ static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
        if (i915.enable_fbc >= 0)
                return !!i915.enable_fbc;
 
+       if (!HAS_FBC(dev_priv))
+               return 0;
+
        if (IS_BROADWELL(dev_priv))
                return 1;
 
        return 0;
 }
 
+static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
+{
+#ifdef CONFIG_INTEL_IOMMU
+       /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
+       if (intel_iommu_gfx_mapped &&
+           (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
+               DRM_INFO("Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
+               return true;
+       }
+#endif
+
+       return false;
+}
+
 /**
  * intel_fbc_init - Initialize FBC
  * @dev_priv: the i915 device
@@ -1253,6 +1270,9 @@ void intel_fbc_init(struct drm_i915_private *dev_priv)
        fbc->active = false;
        fbc->work.scheduled = false;
 
+       if (need_fbc_vtd_wa(dev_priv))
+               mkwrite_device_info(dev_priv)->has_fbc = false;
+
        i915.enable_fbc = intel_sanitize_fbc_option(dev_priv);
        DRM_DEBUG_KMS("Sanitized enable_fbc value: %d\n", i915.enable_fbc);