[PATCH v3 19/25] drm/i915: reinit GT power save during resume

Imre Deak
2014-04-22T17:21:39Z

During runtime suspend there can be a last pending rps.work, so make
sure it's canceled. Note that in the runtime suspend callback we can't
get any RPS interrupts since it's called only after the GPU goes idle
and we set the minimum RPS frequency. The next possibility for an RPS
interrupt is only after getting an RPM ref (for example because of a new
GPU command) and calling the RPM resume callback.

v2:
- patch introduced in v2 of the patchset
v3:
- Change the order of canceling the rps.work and disabling interrupts to
avoid the race between interrupt disabling and the the rps.work. Race
spotted by Ville.

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index b87109c..edd4ab8 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -919,6 +919,12 @@ static int intel_runtime_suspend(struct device *device)

DRM_DEBUG_KMS("Suspending device\n");

+ /*
+ * rps.work can't be rearmed here, since we get here only after making
+ * sure the GPU is idle and the RPS freq is set to the minimum. See
+ * intel_mark_idle().
+ */
+ cancel_work_sync(&dev_priv->rps.work);
intel_runtime_pm_disable_interrupts(dev);

if (IS_GEN6(dev))
@@ -970,6 +976,7 @@ static int intel_runtime_resume(struct device *device)
gen6_update_ring_freq(dev);

intel_runtime_pm_restore_interrupts(dev);
+ intel_reset_gt_powersave(dev);

DRM_DEBUG_KMS("Device resumed\n");
return 0;
--
1.8.4