Re: [PATCH v2 1/4] PM / core: Assign the wakeup_path status flag in __device_prepare()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Dec 29, 2017 at 12:37 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> The PM core in the device_prepare() phase, resets the wakeup_path status
> flag to the value of device_may_wakeup(). This means if a ->prepare() or a
> ->suspend() callback for the device would update the device's wakeup
> setting, this doesn't become reflected in the wakeup_path status flag.
>
> In general this isn't a problem, because wakeup settings are not supposed
> to be changed (via for example calling device_set_wakeup_enable()) during
> any system wide suspend/resume phase.  Nevertheless there are some users,
> which can be considered as legacy, that don't conform to this behaviour.
>
> These legacy cases should be corrected, however until that is done, let's
> address the issue from the PM core, by moving the assignment of the
> wakeup_path status flag to the __device_suspend() phase and after the
> ->suspend() callback has been invoked.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
>  drivers/base/power/main.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index 6e8cc5d..810e5fb 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -1620,6 +1620,8 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
>   End:
>         if (!error) {
>                 dev->power.is_suspended = true;
> +               if (device_may_wakeup(dev))
> +                       dev->power.wakeup_path = true;
>                 dpm_propagate_to_parent(dev);
>                 dpm_clear_suppliers_direct_complete(dev);
>         }
> @@ -1744,7 +1746,7 @@ static int device_prepare(struct device *dev, pm_message_t state)
>
>         device_lock(dev);
>
> -       dev->power.wakeup_path = device_may_wakeup(dev);
> +       dev->power.wakeup_path = false;

If you did "dev->power.wakeup_path = device_may_wakeup(dev)" in
__device_suspend(), it wouldn't need to be cleared here I guess?

>
>         if (dev->power.no_pm_callbacks) {
>                 ret = 1;        /* Let device go direct_complete */
> --
> 2.7.4
>



[Index of Archives]     [Linux Samsung SOC]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Device Mapper]

  Powered by Linux