Re: [PATCH] i2c: busses: Fix a reference count leak.

On Mon, Jun 15, 2020 at 06:31:28AM +0000, Aisheng Dong wrote:

quoted

From: Andy Duan <redacted>
Sent: Monday, June 15, 2020 10:49 AM

From: wu000273@umn.edu <redacted> Sent: Sunday, June 14,
2020 6:12 AM

quoted

From: Qiushi Wu <redacted>

pm_runtime_get_sync() increments the runtime PM usage counter even
when it returns an error code. Thus call pm_runtime_put_noidle() if
pm_runtime_get_sync() fails.

Fixes: 13d6eb20fc79 ("i2c: imx-lpi2c: add runtime pm support")
Signed-off-by: Qiushi Wu <redacted>

Again, which case can trigger the issue ?

It's just error handling improvement because pm_runtime_get_sync() will increase the
reference count even it's failed.

I wonder if such de-reference can be better handled by pm runtime core code.
Copy pm guys to comment.

I started a seperate thread:

https://lkml.org/lkml/2020/6/14/76

Still, on-going discussion if the proper fix is to remove the error
check.