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[0999/1094] drm/i915: fix possible RPM ref leaking during RPS disabling

Message ID 1413889294-31328-1000-git-send-email-dheerajx.s.jamwal@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dheeraj Jamwal Oct. 21, 2014, 10:59 a.m. UTC 
From: Imre Deak <imre.deak@intel.com>

In

commit c6df39b5ea6342323a42edfbeeca0a28c643d7ae
Author: Imre Deak <imre.deak@intel.com>
Date:   Mon Apr 14 20:24:29 2014 +0300

    drm/i915: get a runtime PM ref for the deferred GT powersave enabling

I added an RPM get-ref when enabling RPS from a deferred work, but forgot
to add the corresponding put-ref when canceling the work. This may leave
RPM disabled.

Note that the race is real since we run the rps enabling with a
delayed work item after resume, so leaves enough time (in contrived
examples) to fit a quick autoresum in.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Robert Beckett <robert.beckett@intel.com>
Testecase: igt/pm_rpm/system-suspend
[danvet: Mention testcase and add note.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit e494837aeed358ef58e66154cf7f1dac4ae3a9f5)

Signed-off-by: Dheeraj Jamwal <dheerajx.s.jamwal@intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index bd9568e..af71d3c 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4686,7 +4686,9 @@  void intel_disable_gt_powersave(struct drm_device *dev)
 		ironlake_disable_drps(dev);
 		ironlake_disable_rc6(dev);
 	} else if (IS_GEN6(dev) || IS_GEN7(dev) || IS_BROADWELL(dev)) {
-		cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work);
+		if (cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work))
+			intel_runtime_pm_put(dev_priv);
+
 		cancel_work_sync(&dev_priv->rps.work);
 		mutex_lock(&dev_priv->rps.hw_lock);
 		if (IS_VALLEYVIEW(dev))