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From:   Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc:     linuxarm@huawei.com, mauro.chehab@huawei.com,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Jacopo Mondi <jacopo@jmondi.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: [PATCH 14/25] media: renesas-ceu: Properly check for PM errors
Date:   Wed,  5 May 2021 11:42:04 +0200
Message-Id: <c3b5546444a33840c569e9b7b968f5f81db96ac0.1620207353.git.mchehab+huawei@kernel.org>
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Sender: Mauro Carvalho Chehab <mchehab@kernel.org>
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Right now, the driver just assumes that PM runtime resume
worked, but it may fail.

Well, the pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.

So, using it is tricky. Let's replace it by the new
pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
and return an error if something bad happens.

This should ensure that the PM runtime usage_count will be
properly decremented if an error happens at open time.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/media/platform/renesas-ceu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c
index cd137101d41e..17f01b6e3fe0 100644
--- a/drivers/media/platform/renesas-ceu.c
+++ b/drivers/media/platform/renesas-ceu.c
@@ -1099,10 +1099,10 @@ static int ceu_open(struct file *file)
 
 	mutex_lock(&ceudev->mlock);
 	/* Causes soft-reset and sensor power on on first open */
-	pm_runtime_get_sync(ceudev->dev);
+	ret = pm_runtime_resume_and_get(ceudev->dev);
 	mutex_unlock(&ceudev->mlock);
 
-	return 0;
+	return ret;
 }
 
 static int ceu_release(struct file *file)
-- 
2.30.2