+ David and Steven,

Hi Steven,
    please help to review this patch set.

Thanks
- Kever

Simon South <simon@simonsouth.net> 于2020年12月24日周四 上午12:01写道：

> Commit 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while
> probing") modified rockchip_pwm_probe() to access a PWM device's registers
> directly to check whether or not the device is running, but did not also
> change the function to first enable the device's APB clock to be certain
> the device can respond. This risks hanging the kernel on systems with PWM
> devices that use more than a single clock.
>
> Avoid this by enabling the device's APB clock before accessing its
> registers (and disabling the clock when register access is complete).
>
> Fixes: 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while
> probing")
> Reported-by: Thierry Reding <thierry.reding@gmail.com>
> Suggested-by: Trent Piepho <tpiepho@gmail.com>
> Signed-off-by: Simon South <simon@simonsouth.net>
> ---
>  drivers/pwm/pwm-rockchip.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
> index 77c23a2c6d71..d2058138ce1e 100644
> --- a/drivers/pwm/pwm-rockchip.c
> +++ b/drivers/pwm/pwm-rockchip.c
> @@ -332,9 +332,9 @@ static int rockchip_pwm_probe(struct platform_device
> *pdev)
>                 return ret;
>         }
>
> -       ret = clk_prepare(pc->pclk);
> +       ret = clk_prepare_enable(pc->pclk);
>         if (ret) {
> -               dev_err(&pdev->dev, "Can't prepare APB clk: %d\n", ret);
> +               dev_err(&pdev->dev, "Can't enable APB clk: %d\n", ret);
>                 goto err_clk;
>         }
>
> @@ -364,10 +364,12 @@ static int rockchip_pwm_probe(struct platform_device
> *pdev)
>         if ((ctrl & enable_conf) != enable_conf)
>                 clk_disable(pc->clk);
>
> +       clk_disable(pc->pclk);
> +
>         return 0;
>
>  err_pclk:
> -       clk_unprepare(pc->pclk);
> +       clk_disable_unprepare(pc->pclk);
>  err_clk:
>         clk_disable_unprepare(pc->clk);
>
> --
> 2.29.2
>
>
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