@@ -796,7 +796,7 @@ static int i915_drm_resume(struct drm_device *dev)
static int i915_drm_resume_early(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- int ret = 0;
+ int ret;
/*
* We have a resume ordering issue with the snd-hda driver also
@@ -807,6 +807,36 @@ static int i915_drm_resume_early(struct drm_device *dev)
* FIXME: This should be solved with a special hdmi sink device or
* similar so that power domains can be employed.
*/
+
+ /*
+ * Note that we need to set the power state explicitly, since we
+ * powered off the device during freeze and the PCI core won't power
+ * it back up for us during thaw. Powering off the device during
+ * freeze is not a hard requirement though, and during the
+ * suspend/resume phases the PCI core makes sure we get here with the
+ * device powered on. So in case we change our freeze logic and keep
+ * the device powered we can also remove the following set power state
+ * call.
+ */
+ ret = pci_set_power_state(dev->pdev, PCI_D0);
+ if (ret) {
+ DRM_ERROR("failed to set PCI D0 power state (%d)\n", ret);
+ return ret;
+ }
+
+ /*
+ * Note that pci_enable_device() first enables any parent bridge
+ * device and only then sets the power state for this device. The
+ * bridge enabling is a nop though, since bridge devices are resumed
+ * first. The order of enabling power and enabling the device is
+ * imposed by the PCI core as described above, so here we preserve the
+ * same order for the freeze/thaw phases.
+ *
+ * TODO: eventually we should remove pci_disable_device() /
+ * pci_enable_enable_device() from suspend/resume. Due to how they
+ * depend on the device enable refcount we can't anyway depend on them
+ * disabling/enabling the device.
+ */
if (pci_enable_device(dev->pdev))
return -EIO;