On Fri, Dec 29, 2017 at 12:37 PM, Ulf Hansson <ulf.hans...@linaro.org> 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.hans...@linaro.org>
> ---
> 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
>
