Re: [PATCH v2] gpio: mxc: add runtime pm support

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Wed, Jul 5, 2023 at 6:37 PM Shenwei Wang <shenwei.wang@xxxxxxx> wrote:
>
> Adds runtime PM support and allow the GPIO controller to enter
> into runtime suspend automatically when not in use to save power.
> However, it will automatically resume and enable clocks when a
> GPIO or IRQ is requested.
>
> While putting the GPIO module itself into power saving mode may not
> have an obvious impact on current dissipation, the function is necessary
> because the GPIO module disables its clock when idle. This enables the
> system an opportunity to power off the parent subsystem, and this conserves
> more power. The typical i.MX8 SoC features up to 8 GPIO controllers, but
> most of the controllers often remain unused.


...

> +       pm_runtime_set_active(&pdev->dev);
> +       pm_runtime_enable(&pdev->dev);
> +       err = pm_runtime_resume_and_get(&pdev->dev);
> +       if (err < 0)
> +               goto out_pm_dis;

So, after this if an error happens, you will have PM left enabled and
the next probe won't work as expected, right?

...

>         platform_set_drvdata(pdev, port);
> +       pm_runtime_put_autosuspend(&pdev->dev);
>
>         return 0;

...something here is missing?

> +out_pm_dis:
> +       pm_runtime_disable(&pdev->dev);
> +       clk_disable_unprepare(port->clk);
>  out_irqdomain_remove:
>         irq_domain_remove(port->domain);
>  out_bgio:

-- 
With Best Regards,
Andy Shevchenko