linux-kernel - [PATCH v1 1/2] media: hi846: fix usage of pm_runtime_get_if_in

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Message-Id: <20230405092904.1129395-2-martin.kepplinger@puri.sm>
Date:   Wed,  5 Apr 2023 11:29:03 +0200
From:   Martin Kepplinger <martin.kepplinger@...i.sm>
To:     mchehab@...nel.org, laurent.pinchart@...asonboard.com
Cc:     kernel@...i.sm, linux-media@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Martin Kepplinger <martin.kepplinger@...i.sm>
Subject: [PATCH v1 1/2] media: hi846: fix usage of pm_runtime_get_if_in_use()

pm_runtime_get_if_in_use() does not only return nonzero values when
the device is in use, it can return a negative errno too.

And especially during resuming from system suspend, when runtime pm
is not yet up again, this can very well happen. And in such a case
the subsequent pm_runtime_put() call would result in a refcount underflow!

Fix it by correctly using pm_runtime_get_if_in_use().

Signed-off-by: Martin Kepplinger <martin.kepplinger@...i.sm>
---
 drivers/media/i2c/hi846.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/hi846.c b/drivers/media/i2c/hi846.c
index 5b5ea5425e984..0b0eda2e223cd 100644
--- a/drivers/media/i2c/hi846.c
+++ b/drivers/media/i2c/hi846.c
@@ -1544,7 +1544,7 @@ static int hi846_set_ctrl(struct v4l2_ctrl *ctrl)
 					 exposure_max);
 	}
 
-	if (!pm_runtime_get_if_in_use(&client->dev))
+	if (pm_runtime_get_if_in_use(&client->dev) <= 0)
 		return 0;
 
 	switch (ctrl->id) {
-- 
2.30.2