On 26 January 2018 at 09:38, Jia-Ju Bai <baijiaju1...@gmail.com> wrote:
> After checking all possible call chains to genpd_dev_pm_detach() and
> genpd_dev_pm_attach() here,
> my tool finds that these functions are never called in atomic context,
> namely never in an interrupt handler or holding a spinlock.
> Thus mdelay can be replaced with msleep to avoid busy wait.
>
> This is found by a static analysis tool named DCNS written by myself.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com>
> ---
>  drivers/base/power/domain.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 0c80bea..f84ac72 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -2144,7 +2144,7 @@ static void genpd_dev_pm_detach(struct device *dev, 
> bool power_off)
>                 if (ret != -EAGAIN)
>                         break;
>
> -               mdelay(i);
> +               msleep(i);

This looks like a nice improvement, however moving to msleep() makes
the call to cond_resched() below a bit superfluous. Perhaps remove
that as well.

>                 cond_resched();
>         }
>
> @@ -2231,7 +2231,7 @@ int genpd_dev_pm_attach(struct device *dev)
>                 if (ret != -EAGAIN)
>                         break;
>
> -               mdelay(i);
> +               msleep(i);

Ditto.

>                 cond_resched();
>         }
>         mutex_unlock(&gpd_list_lock);
> --
> 1.7.9.5
>

Kind regards
Uffe

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