diff options
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_drv.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 452bc512e6a7..e216c21110e4 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -538,6 +538,35 @@ int i915_resume(struct drm_device *dev) if (dev->switch_power_state == DRM_SWITCH_POWER_OFF) return 0; + /* + * 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; |