Hello,
Comments inline
On Thu, Jul 25, 2019 at 10:55 AM Chuhong Yuan <hslester96@xxxxxxxxx> wrote:
>
> Make use of devm_counter_register.
> Then we can remove redundant unregistration API
> usage to make code simpler.
>
> Signed-off-by: Chuhong Yuan <hslester96@xxxxxxxxx>
> ---
> drivers/counter/ftm-quaddec.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/counter/ftm-quaddec.c b/drivers/counter/ftm-quaddec.c
> index 68a9b7393457..bccbca8681b6 100644
> --- a/drivers/counter/ftm-quaddec.c
> +++ b/drivers/counter/ftm-quaddec.c
> @@ -317,7 +317,7 @@ static int ftm_quaddec_probe(struct platform_device *pdev)
>
> ftm_quaddec_init(ftm);
>
> - ret = counter_register(&ftm->counter);
> + ret = devm_counter_register(&pdev->dev, &ftm->counter);
> if (ret)
> ftm_quaddec_disable(ftm);
>
> @@ -328,8 +328,6 @@ static int ftm_quaddec_remove(struct platform_device *pdev)
> {
> struct ftm_quaddec *ftm = platform_get_drvdata(pdev);
>
> - counter_unregister(&ftm->counter);
> -
The orders of (de)initialization should be kept symmetrical.
In this case, now that counter_unregister() will be called via devm,
it will be executed after ftm_quaddec_remove()
This introduces a race condition where the ftm-quaddec is disabled but
the counter entry itself is not.
Somebody else (William?) should confirm this.
> ftm_quaddec_disable(ftm);
>
> return 0;
> --
> 2.20.1
>
