[Intel-gfx] [PATCH v2 6/8] drm/i915: Disable power management for i915 driver in VM

[Yu Zhang]

In XenGT, GPU power management is controlled by host i915
driver, so there is no need to provide virtualized GPU PM
support. In the future it might be useful to gather VM
input for freq boost, but now let's disable it simply.

v2: 
take Chris' comments:
        - do not special case this to gen6+

Signed-off-by: Yu Zhang <yu.c.zhang at linux.intel.com>
Signed-off-by: Jike Song <jike.song at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 50cf96b..3a80557 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5304,6 +5304,10 @@ void intel_enable_gt_powersave(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	/* Powersaving is controlled by the host when inside a VM */
+	if (intel_vgpu_active(dev))
+		return;
+
 	if (IS_IRONLAKE_M(dev)) {
 		mutex_lock(&dev->struct_mutex);
 		ironlake_enable_drps(dev);
-- 
1.9.1