drm/i915: By default, enable RC6 on IVB and SNB when reasonable

[deliverable/linux.git] / drivers / gpu / drm / i915 / intel_display.c

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 633c69365388481487380ebad4ed1c426523588a..d544de9e66345a559030b866f9c109e4afce386d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -38,8 +38,8 @@
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include "drm_dp_helper.h"
-
 #include "drm_crtc_helper.h"
+#include <linux/dma_remapping.h>
 
 #define HAS_eDP (intel_pipe_has_type(crtc, INTEL_OUTPUT_EDP))
 
@@ -7887,6 +7887,33 @@ void intel_init_emon(struct drm_device *dev)
        dev_priv->corr = (lcfuse & LCFUSE_HIV_MASK);
 }
 
+static bool intel_enable_rc6(struct drm_device *dev)
+{
+       /*
+        * Respect the kernel parameter if it is set
+        */
+       if (i915_enable_rc6 >= 0)
+               return i915_enable_rc6;
+
+       /*
+        * Disable RC6 on Ironlake
+        */
+       if (INTEL_INFO(dev)->gen == 5)
+               return 0;
+
+       /*
+        * Enable rc6 on Sandybridge if DMA remapping is disabled
+        */
+       if (INTEL_INFO(dev)->gen == 6) {
+               DRM_DEBUG_DRIVER("Sandybridge: intel_iommu_enabled %s -- RC6 %sabled\n",
+                                intel_iommu_enabled ? "true" : "false",
+                                !intel_iommu_enabled ? "en" : "dis");
+               return !intel_iommu_enabled;
+       }
+       DRM_DEBUG_DRIVER("RC6 enabled\n");
+       return 1;
+}
+
 void gen6_enable_rps(struct drm_i915_private *dev_priv)
 {
        u32 rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
@@ -7923,7 +7950,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
        I915_WRITE(GEN6_RC6p_THRESHOLD, 100000);
        I915_WRITE(GEN6_RC6pp_THRESHOLD, 64000); /* unused */
 
-       if (i915_enable_rc6)
+       if (intel_enable_rc6(dev_priv->dev))
                rc6_mask = GEN6_RC_CTL_RC6p_ENABLE |
                        GEN6_RC_CTL_RC6_ENABLE;
 
@@ -8372,7 +8399,7 @@ void ironlake_enable_rc6(struct drm_device *dev)
        /* rc6 disabled by default due to repeated reports of hanging during
         * boot and resume.
         */
-       if (!i915_enable_rc6)
+       if (!intel_enable_rc6(dev))
                return;
 
        mutex_lock(&dev->struct_mutex);