Merge branch 'devfreq-for-next' of git://git.infradead.org/users/kmpark/linux-samsung into pm-devfreq

* 'devfreq-for-next' of git://git.infradead.org/users/kmpark/linux-samsung: (765 commits)
  PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
  pci: Fix hotplug of Express Module with pci bridges
  i2c-eg20t: correct the driver init order of pch_i2c_probe()
  I2C: OMAP: fix FIFO usage for OMAP4
  i2c-s3c2410: Fix return code of s3c24xx_i2c_parse_dt_gpio
  i2c: i2c-s3c2410: Add a cpu_relax() to busy wait for bus idle
  Linux 3.2-rc6
  Revert "drm/i915: fix infinite recursion on unbind due to ilk vt-d w/a"
  btrfs: lower the dirty balance poll interval
  drm/i915/dp: Dither down to 6bpc if it makes the mode fit
  drm/i915: enable semaphores on per-device defaults
  drm/i915: don't set unpin_work if vblank_get fails
  drm/i915: By default, enable RC6 on IVB and SNB when reasonable
  iommu: Export intel_iommu_enabled to signal when iommu is in use
  drm/i915/sdvo: Include LVDS panels for the IS_DIGITAL check
  drm/i915: prevent division by zero when asking for chipset power
  drm/i915: add PCH info to i915_capabilities
  drm/i915: set the right SDVO transcoder for CPT
  drm/i915: no-lvds quirk for ASUS AT5NM10T-I
  sched: Fix select_idle_sibling() regression in selecting an idle SMT sibling
  ...

1 files changed, 18 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 3693e83a97f3..c681dc149d2a 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -32,6 +32,7 @@
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
+#include <linux/dma_remapping.h>
 
 struct change_domains {
 	uint32_t invalidate_domains;
@@ -746,6 +747,22 @@ i915_gem_execbuffer_flush(struct drm_device *dev,
 	return 0;
 }
 
+static bool
+intel_enable_semaphores(struct drm_device *dev)
+{
+	if (INTEL_INFO(dev)->gen < 6)
+		return 0;
+
+	if (i915_semaphores >= 0)
+		return i915_semaphores;
+
+	/* Enable semaphores on SNB when IO remapping is off */
+	if (INTEL_INFO(dev)->gen == 6)
+		return !intel_iommu_enabled;
+
+	return 1;
+}
+
 static int
 i915_gem_execbuffer_sync_rings(struct drm_i915_gem_object *obj,
 			       struct intel_ring_buffer *to)
@@ -758,7 +775,7 @@ i915_gem_execbuffer_sync_rings(struct drm_i915_gem_object *obj,
 		return 0;
 
 	/* XXX gpu semaphores are implicated in various hard hangs on SNB */
-	if (INTEL_INFO(obj->base.dev)->gen < 6 || !i915_semaphores)
+	if (!intel_enable_semaphores(obj->base.dev))
 		return i915_gem_object_wait_rendering(obj);
 
 	idx = intel_ring_sync_index(from, to);