On Mon 01 Nov 11:59 PDT 2021, Matthias Kaehlcke wrote:
> Hi Sandeep,
>
> On Mon, Nov 01, 2021 at 01:23:40PM +0530, Sandeep Maheswaram wrote:
> > During suspend check if any wakeup capable devices are connected to the
> > controller (directly or through hubs), and set the wakeup capable property
> > for xhci plat device.
> >
> > Signed-off-by: Sandeep Maheswaram <quic_c_sanm@xxxxxxxxxxx>
> > ---
> > drivers/usb/host/xhci-plat.c | 12 ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> > index c1edcc9..7ab272b 100644
> > --- a/drivers/usb/host/xhci-plat.c
> > +++ b/drivers/usb/host/xhci-plat.c
> > @@ -431,6 +431,14 @@ static int xhci_plat_remove(struct platform_device *dev)
> > return 0;
> > }
> >
> > +static void xhci_dwc3_suspend_quirk(struct usb_hcd *hcd, struct device *dev)
> > +{
> > + if (usb_wakeup_enabled_descendants(hcd->self.root_hub))
> > + device_set_wakeup_capable(dev, true);
> > + else
> > + device_set_wakeup_capable(dev, false);
>
> IIUC wakeup capability is typically a static property that reflects the
> actual hardware (or firmware) support for wakeup. In that sense it doesn't
> seem a good idea to change it dynamically at suspend time, depending on
> what is connected to the bus. I understand though that the odd split
> of the dwc3 driver makes it hard to do things properly ...
>
> Earlier in this discussion Felipe suggested to add a function like
> device_children_wakeup_capable(), to avoid having to call
> usb_wakeup_enabled_descendants() from the dwc3 drivers.
>
> Below is an initial implementation for device_children_wakeup_capable(),
> could you try if calling it from dwc3_suspend/resume_common() and
> dwc3_qcom_suspend() would work instead of relying on the wakeup
> capability?
>
> Thanks
>
> Matthias
>
> From 97c838334045ed67c3943f8e035ac70acd12b89b Mon Sep 17 00:00:00 2001
> From: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> Date: Mon, 1 Nov 2021 11:37:19 -0700
> Subject: [PATCH] PM / wakeup: Add device_children_wakeup_capable()
>
> Add device_children_wakeup_capable() which checks whether the device itself
> or one if its descendants is wakeup capable.
>
> Change-Id: Ib359eb5ac8650ddf9889c7d1f77707f50777fe99
> Suggested-by: Felipe Balbi <balbi@xxxxxxxxxx>
> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Looks neat and useful.
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
(Without the Change-Id of course...)
Regards,
Bjorn
> ---
> drivers/base/power/wakeup.c | 17 +++++++++++++++++
> include/linux/pm_wakeup.h | 6 ++++++
> 2 files changed, 23 insertions(+)
>
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index 9c0932603642..2aee7fa8230f 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -483,6 +483,23 @@ int device_set_wakeup_enable(struct device *dev, bool enable)
> }
> EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
>
> +static int __device_children_wakeup_capable(struct device *dev, void *dummy)
> +{
> + return device_may_wakeup(dev) ||
> + device_for_each_child(dev, NULL, __device_children_wakeup_capable);
> +}
> +
> +/**
> + * device_children_wakeup_capable - Check whether a device or one of its descendants is
> + * wakeup capable.
> + * @dev: Device to handle.
> + */
> +bool device_children_wakeup_capable(struct device *dev)
> +{
> + return __device_children_wakeup_capable(dev, NULL);
> +}
> +EXPORT_SYMBOL_GPL(device_children_wakeup_capable);
> +
> /**
> * wakeup_source_not_registered - validate the given wakeup source.
> * @ws: Wakeup source to be validated.
> diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
> index 661efa029c96..a0ca42aac6d6 100644
> --- a/include/linux/pm_wakeup.h
> +++ b/include/linux/pm_wakeup.h
> @@ -97,6 +97,7 @@ extern int device_wakeup_disable(struct device *dev);
> extern void device_set_wakeup_capable(struct device *dev, bool capable);
> extern int device_init_wakeup(struct device *dev, bool val);
> extern int device_set_wakeup_enable(struct device *dev, bool enable);
> +extern bool device_children_wakeup_capable(struct device *dev);
> extern void __pm_stay_awake(struct wakeup_source *ws);
> extern void pm_stay_awake(struct device *dev);
> extern void __pm_relax(struct wakeup_source *ws);
> @@ -167,6 +168,11 @@ static inline bool device_may_wakeup(struct device *dev)
>
> static inline void device_set_wakeup_path(struct device *dev) {}
>
> +static inline bool device_children_wakeup_capable(struct device *dev)
> +{
> + return false;
> +}
> +
> static inline void __pm_stay_awake(struct wakeup_source *ws) {}
>
> static inline void pm_stay_awake(struct device *dev) {}
