linux-kernel - Re: [RFC PATCH V1 1/2] clk: use atomic runtime pm api in clk_core_is

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Date:   Fri, 22 Dec 2017 13:51:05 +0100
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     Dong Aisheng <aisheng.dong@....com>
Cc:     linux-clk <linux-clk@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-arm-kernel@...ts.infradead.org,
        Stephen Boyd <sboyd@...eaurora.org>,
        Mike Turquette <mturquette@...libre.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>
Subject: Re: [RFC PATCH V1 1/2] clk: use atomic runtime pm api in clk_core_is_enabled

On 22 December 2017 at 10:46, Dong Aisheng <aisheng.dong@....com> wrote:
> Current clk_pm_runtime_put is using pm_runtime_put_sync which
> is not safe to be called in clk_core_is_enabled as it should
> be able to run in atomic context.
>
> Thus use pm_runtime_put instead which is atomic safe.
>
> Cc: Stephen Boyd <sboyd@...eaurora.org>
> Cc: Michael Turquette <mturquette@...libre.com>
> Cc: Ulf Hansson <ulf.hansson@...aro.org>
> Cc: Marek Szyprowski <m.szyprowski@...sung.com>
> Fixes: 9a34b45397e5 ("clk: Add support for runtime PM")
> Signed-off-by: Dong Aisheng <aisheng.dong@....com>

Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>

Kind regards
Uffe

> ---
>  drivers/clk/clk.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 5ec5809..e24968f 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -227,7 +227,8 @@ static bool clk_core_is_enabled(struct clk_core *core)
>
>         ret = core->ops->is_enabled(core->hw);
>  done:
> -       clk_pm_runtime_put(core);
> +       if (core->dev)
> +               pm_runtime_put(core->dev);
>
>         return ret;
>  }
> --
> 2.7.4
>