[PATCH 6.4 576/800] media: hi846: fix usage of pm_runtime_get_if_in_use()

Greg Kroah-Hartman
2023-07-16T20:19:46Z

From: Martin Kepplinger <martin.kepplinger@puri.sm>

[ Upstream commit 04fc06f6dc1592ed5d675311ac50d8fba5db62ab ]

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, -EAGAIN is being returned, so the subsequent
pm_runtime_put() call results in a refcount underflow.

Fix system-resume by handling -EAGAIN of pm_runtime_get_if_in_use().

Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Fixes: e8c0882685f9 ("media: i2c: add driver for the SK Hynix Hi-846 8M pixel camera")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/i2c/hi846.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/hi846.c b/drivers/media/i2c/hi846.c
index 306dc35e925fd..f8709cdf28b39 100644
--- a/drivers/media/i2c/hi846.c
+++ b/drivers/media/i2c/hi846.c
@@ -1353,7 +1353,8 @@ static int hi846_set_ctrl(struct v4l2_ctrl *ctrl)
exposure_max);
}

- if (!pm_runtime_get_if_in_use(&client->dev))
+ ret = pm_runtime_get_if_in_use(&client->dev);
+ if (!ret || ret == -EAGAIN)
return 0;

switch (ctrl->id) {
--
2.39.2