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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
        Steven Price <steven.price@arm.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.8 163/464] drm/panfrost: Fix inbalance of devfreq record_busy/idle()
Date:   Mon, 17 Aug 2020 17:11:56 +0200
Message-Id: <20200817143841.619947582@linuxfoundation.org>
In-Reply-To: <20200817143833.737102804@linuxfoundation.org>
References: <20200817143833.737102804@linuxfoundation.org>
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From: Steven Price <steven.price@arm.com>

[ Upstream commit b99773ef258e628bd53cab22d450a755b73b4d55 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/panfrost/panfrost_job.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index 7914b15708412..f9519afca29d9 100644
--- 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++)
-- 
2.25.1