media: renesas-ceu: Properly check for PM errors

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>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c
index cd13710..17f01b6 100644 (file)
--- 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)