drm/panfrost: Fix inbalance of devfreq record_busy/idle()

The calls to panfrost_devfreq_record_busy() and
panfrost_devfreq_record_idle() must be balanced to ensure that the
devfreq utilisation is correctly reported. But there are two cases where
this doesn't work correctly.

In panfrost_job_hw_submit() if pm_runtime_get_sync() fails or the
WARN_ON() fires then no call to panfrost_devfreq_record_busy() is made,
but when the job times out the corresponding _record_idle() call is
still made in panfrost_job_timedout(). Move the call up to ensure that
it always happens.

Secondly panfrost_job_timedout() only makes a single call to
panfrost_devfreq_record_idle() even if it is cleaning up multiple jobs.
Move the call inside the loop to ensure that the number of
_record_idle() calls matches the number of _record_busy() calls.

Fixes: 9e62b885f715 ("drm/panfrost: Simplify devfreq utilisation tracking")
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200522153653.40754-1-steven.price@arm.com

diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index b2f09c0..ac87ef6 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -145,6 +145,8 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
        u64 jc_head = job->jc;
        int ret;
 
+       panfrost_devfreq_record_busy(pfdev);
+
        ret = pm_runtime_get_sync(pfdev->dev);
        if (ret < 0)
                return;
@@ -155,7 +157,6 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
        }
 
        cfg = panfrost_mmu_as_get(pfdev, &job->file_priv->mmu);
-       panfrost_devfreq_record_busy(pfdev);
 
        job_write(pfdev, JS_HEAD_NEXT_LO(js), jc_head & 0xFFFFFFFF);
        job_write(pfdev, JS_HEAD_NEXT_HI(js), jc_head >> 32);
@@ -410,12 +411,12 @@ static void panfrost_job_timedout(struct drm_sched_job *sched_job)
        for (i = 0; i < NUM_JOB_SLOTS; i++) {
                if (pfdev->jobs[i]) {
                        pm_runtime_put_noidle(pfdev->dev);
+                       panfrost_devfreq_record_idle(pfdev);
                        pfdev->jobs[i] = NULL;
                }
        }
        spin_unlock_irqrestore(&pfdev->js->job_lock, flags);
 
-       panfrost_devfreq_record_idle(pfdev);
        panfrost_device_reset(pfdev);
 
        for (i = 0; i < NUM_JOB_SLOTS; i++)