[PATCH v2 2/2] drm/msm/gpu: Cancel idle/boost work on suspend

[Rob Clark <robdclark@gmail.com>]

From: Rob Clark <robdclark@chromium.org>

With system suspend using pm_runtime_force_suspend() we can't rely on
the pm_runtime_get_if_in_use() trick to deal with devfreq callbacks
after (or racing with) suspend.  So flush any pending idle or boost
work in the suspend path.

v2: s/ret/remaining [sboyd], and switch to using active_submits count
    to ensure we aren't racing with submit cleanup (and devfreq idle
    work getting scheduled, etc)

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/msm_gpu_devfreq.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c
index 62405e980925..9bf319be11f6 100644
--- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c
+++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c
@@ -133,6 +133,18 @@ void msm_devfreq_init(struct msm_gpu *gpu)
 			      CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 }
 
+static void cancel_idle_work(struct msm_gpu_devfreq *df)
+{
+	hrtimer_cancel(&df->idle_work.timer);
+	kthread_cancel_work_sync(&df->idle_work.work);
+}
+
+static void cancel_boost_work(struct msm_gpu_devfreq *df)
+{
+	hrtimer_cancel(&df->boost_work.timer);
+	kthread_cancel_work_sync(&df->boost_work.work);
+}
+
 void msm_devfreq_cleanup(struct msm_gpu *gpu)
 {
 	struct msm_gpu_devfreq *df = &gpu->devfreq;
@@ -152,7 +164,12 @@ void msm_devfreq_resume(struct msm_gpu *gpu)
 
 void msm_devfreq_suspend(struct msm_gpu *gpu)
 {
-	devfreq_suspend_device(gpu->devfreq.devfreq);
+	struct msm_gpu_devfreq *df = &gpu->devfreq;
+
+	devfreq_suspend_device(df->devfreq);
+
+	cancel_idle_work(df);
+	cancel_boost_work(df);
 }
 
 static void msm_devfreq_boost_work(struct kthread_work *work)
@@ -196,7 +213,7 @@ void msm_devfreq_active(struct msm_gpu *gpu)
 	/*
 	 * Cancel any pending transition to idle frequency:
 	 */
-	hrtimer_cancel(&df->idle_work.timer);
+	cancel_idle_work(df);
 
 	idle_time = ktime_to_ms(ktime_sub(ktime_get(), df->idle_time));
 
-- 
2.33.1