[PATCH] media: i2c: ov2740: fix power leak on remove while runtime-active

[PATCH] media: i2c: ov2740: fix power leak on remove while runtime-active

[Cong Nguyen]

ov2740_remove() calls pm_runtime_disable() and nothing else -- it
never calls ov2740_suspend(), which actually powers the sensor down
(asserts reset/powerdown gpios, disables the clock, disables the bulk
regulators). pm_runtime_disable() only blocks future auto suspend/
resume, it doesn't force a final one.

If unbound while the device is genuinely runtime-active (streaming,
or an open subdev fd holding a PM reference), the regulators, clock
and gpios stay in their active state with no code path left to ever
release them.

Call ov2740_suspend() in that case, guarded by
pm_runtime_status_suspended() so the common already-suspended case
isn't suspended twice -- same guard sibling imx412.c's remove() uses.

Moved remove() after suspend()/resume()'s definitions since it now
calls them directly.

Fixes: 866edc895171 ("media: i2c: Add ov2740 image sensor driver")
Assisted-by: LLM
Signed-off-by: Cong Nguyen <congnt264@gmail.com>
---
 drivers/media/i2c/ov2740.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c
index fb590dfadda1..fc3710cf3c0e 100644
--- a/drivers/media/i2c/ov2740.c
+++ b/drivers/media/i2c/ov2740.c
@@ -1198,17 +1198,6 @@ static int ov2740_check_hwcfg(struct ov2740 *ov2740)
 	return ret;
 }
 
-static void ov2740_remove(struct i2c_client *client)
-{
-	struct v4l2_subdev *sd = i2c_get_clientdata(client);
-
-	v4l2_async_unregister_subdev(sd);
-	media_entity_cleanup(&sd->entity);
-	v4l2_subdev_cleanup(sd);
-	v4l2_ctrl_handler_free(sd->ctrl_handler);
-	pm_runtime_disable(&client->dev);
-}
-
 static int ov2740_nvmem_read(void *priv, unsigned int off, void *val,
 			     size_t count)
 {
@@ -1323,6 +1312,19 @@ static int ov2740_resume(struct device *dev)
 	return 0;
 }
 
+static void ov2740_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+	v4l2_subdev_cleanup(sd);
+	v4l2_ctrl_handler_free(sd->ctrl_handler);
+	pm_runtime_disable(&client->dev);
+	if (!pm_runtime_status_suspended(&client->dev))
+		ov2740_suspend(&client->dev);
+}
+
 static int ov2740_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
-- 
2.25.1