| Message ID | 1416849900-29959-3-git-send-email-kiran.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi Felipe, On 25 November 2014 at 20:15, Felipe Balbi <balbi@ti.com> wrote: > On Tue, Nov 25, 2014 at 07:06:18AM +0000, Peter Chen wrote: >> >> > >> > usb: phy: hold wakeupsource when USB is enumerated in peripheral mode >> > >> > Some systems require a mechanism to prevent system to enter into suspend >> > state when USB is connected and enumerated in peripheral mode. >> > >> > This patch provides an interface to hold a wakeupsource to prevent suspend. >> > PHY drivers can use this interface when USB is connected and enumerated in >> > peripheral mode. >> > >> > A timed wakeupsource is temporarily held on USB disconnect events, to allow >> > the rest of the system to react to the USB disconnection (dropping host >> > sessions, updating charger status, etc.) prior to re-allowing suspend. >> > >> >> Hi Kiran & Felipe, >> >> Just two questions for this series >> >> - Will it be the default behavior for all peripheral drivers? >> - If the peripheral driver's PHY driver does not vbus event, how to >> support it? >> For example, chipidea udc driver has its vbus interface at its >> controller register. > > hmm, good point. Since it's so late, I'll just go ahead and drop > $subject from v3.20. Let's delay only $subject to v3.20 merge window so > we have some more time to discuss these details. I am just curious to know/understand why this feature needs to be default behavior for all peripheral drivers? If this needs to be default behavior, could you please suggest any alternate plan/design for this feature so that i can incorporate them in new patch. Regards, Kiran > > cheers > > -- > balbi -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Felipe, On 1 December 2014 at 11:09, Kiran Raparthy <kiran.kumar@linaro.org> wrote: > Hi Felipe, > > On 25 November 2014 at 20:15, Felipe Balbi <balbi@ti.com> wrote: >> On Tue, Nov 25, 2014 at 07:06:18AM +0000, Peter Chen wrote: >>> >>> > >>> > usb: phy: hold wakeupsource when USB is enumerated in peripheral mode >>> > >>> > Some systems require a mechanism to prevent system to enter into suspend >>> > state when USB is connected and enumerated in peripheral mode. >>> > >>> > This patch provides an interface to hold a wakeupsource to prevent suspend. >>> > PHY drivers can use this interface when USB is connected and enumerated in >>> > peripheral mode. >>> > >>> > A timed wakeupsource is temporarily held on USB disconnect events, to allow >>> > the rest of the system to react to the USB disconnection (dropping host >>> > sessions, updating charger status, etc.) prior to re-allowing suspend. >>> > >>> >>> Hi Kiran & Felipe, >>> >>> Just two questions for this series >>> >>> - Will it be the default behavior for all peripheral drivers? >>> - If the peripheral driver's PHY driver does not vbus event, how to >>> support it? >>> For example, chipidea udc driver has its vbus interface at its >>> controller register. >> >> hmm, good point. Since it's so late, I'll just go ahead and drop >> $subject from v3.20. Let's delay only $subject to v3.20 merge window so >> we have some more time to discuss these details. > > I am just curious to know/understand why this feature needs to be > default behavior for all peripheral drivers? > If this needs to be default behavior, could you please suggest any > alternate plan/design for this feature so that i can incorporate them > in new patch. > Regards, > Kiran Just a gentle reminder to consider the patch. > >> >> cheers >> >> -- >> balbi Regards, Kiran -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
H Peter, Felipe, On 14 January 2015 at 06:56, Peter Chen <peter.chen@freescale.com> wrote: > On Tue, Jan 13, 2015 at 10:18:02AM -0600, Felipe Balbi wrote: >> On Tue, Jan 13, 2015 at 04:02:20PM +0530, Kiran Raparthy wrote: >> > Hi Felipe, >> > >> > On 1 December 2014 at 11:09, Kiran Raparthy <kiran.kumar@linaro.org> wrote: >> > > Hi Felipe, >> > > >> > > On 25 November 2014 at 20:15, Felipe Balbi <balbi@ti.com> wrote: >> > >> On Tue, Nov 25, 2014 at 07:06:18AM +0000, Peter Chen wrote: >> > >>> >> > >>> > >> > >>> > usb: phy: hold wakeupsource when USB is enumerated in peripheral mode >> > >>> > >> > >>> > Some systems require a mechanism to prevent system to enter into suspend >> > >>> > state when USB is connected and enumerated in peripheral mode. >> > >>> > >> > >>> > This patch provides an interface to hold a wakeupsource to prevent suspend. >> > >>> > PHY drivers can use this interface when USB is connected and enumerated in >> > >>> > peripheral mode. >> > >>> > >> > >>> > A timed wakeupsource is temporarily held on USB disconnect events, to allow >> > >>> > the rest of the system to react to the USB disconnection (dropping host >> > >>> > sessions, updating charger status, etc.) prior to re-allowing suspend. >> > >>> > >> > >>> >> > >>> Hi Kiran & Felipe, >> > >>> >> > >>> Just two questions for this series >> > >>> >> > >>> - Will it be the default behavior for all peripheral drivers? >> > >>> - If the peripheral driver's PHY driver does not vbus event, how to >> > >>> support it? >> > >>> For example, chipidea udc driver has its vbus interface at its >> > >>> controller register. >> > >> >> > >> hmm, good point. Since it's so late, I'll just go ahead and drop >> > >> $subject from v3.20. Let's delay only $subject to v3.20 merge window so >> > >> we have some more time to discuss these details. >> > > >> > > I am just curious to know/understand why this feature needs to be >> > > default behavior for all peripheral drivers? >> > > If this needs to be default behavior, could you please suggest any >> > > alternate plan/design for this feature so that i can incorporate them >> > > in new patch. >> > > Regards, >> > > Kiran >> > >> > Just a gentle reminder to consider the patch. >> >> sorry, for the delay... man this release round has been hectic. We still >> haven't sorted out what should be the default behavior here, considering >> some PHYs will not be able to report VBUS levels, I'm not sure what we >> should do here. >> > > My opinion is: if we need this feature, we should depend on gadget's > state, eg 'configured', not vbus level. The system suspend should be > allowed if the gadget state is 'suspended' which vbus is still there. > Kiran is unable to continue on this patch anymore, so despite my very limited usb experience, I would like to take this over and with your help, take it to closure. From what I understand, it might be possible to do this either at the usb controller driver (where it detects if it has enumerated in host mode or device mode) or in the extcon driver (where it detects VBUS etc..) - which would be a cleaner / more logical way to do it? Thanks for all your help! > -- > > Best Regards, > Peter Chen > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
Hi Peter, On 8 June 2015 at 14:02, Peter Chen <peter.chen@freescale.com> wrote: > On Mon, Jun 08, 2015 at 12:37:00PM +0530, Sumit Semwal wrote: >> H Peter, Felipe, >> >> On 14 January 2015 at 06:56, Peter Chen <peter.chen@freescale.com> wrote: >> > On Tue, Jan 13, 2015 at 10:18:02AM -0600, Felipe Balbi wrote: >> >> On Tue, Jan 13, 2015 at 04:02:20PM +0530, Kiran Raparthy wrote: >> >> > Hi Felipe, >> >> > >> >> > On 1 December 2014 at 11:09, Kiran Raparthy <kiran.kumar@linaro.org> wrote: >> >> > > Hi Felipe, >> >> > > >> >> > > On 25 November 2014 at 20:15, Felipe Balbi <balbi@ti.com> wrote: >> >> > >> On Tue, Nov 25, 2014 at 07:06:18AM +0000, Peter Chen wrote: >> >> > >>> >> >> > >>> > >> >> > >>> > usb: phy: hold wakeupsource when USB is enumerated in peripheral mode >> >> > >>> > >> >> > >>> > Some systems require a mechanism to prevent system to enter into suspend >> >> > >>> > state when USB is connected and enumerated in peripheral mode. >> >> > >>> > >> >> > >>> > This patch provides an interface to hold a wakeupsource to prevent suspend. >> >> > >>> > PHY drivers can use this interface when USB is connected and enumerated in >> >> > >>> > peripheral mode. >> >> > >>> > >> >> > >>> > A timed wakeupsource is temporarily held on USB disconnect events, to allow >> >> > >>> > the rest of the system to react to the USB disconnection (dropping host >> >> > >>> > sessions, updating charger status, etc.) prior to re-allowing suspend. >> >> > >>> > >> >> > >>> <snip> >> >> Kiran is unable to continue on this patch anymore, so despite my very >> limited usb experience, I would like to take this over and with your >> help, take it to closure. >> >> From what I understand, it might be possible to do this either at the >> usb controller driver (where it detects if it has enumerated in host >> mode or device mode) or in the extcon driver (where it detects VBUS >> etc..) - which would be a cleaner / more logical way to do it? >> >> Thanks for all your help! > > I added my suggestions below: > > My opinion is: if we need this feature, we should depend on gadget's > state, eg 'configured', not vbus level. The system suspend should be > allowed if the gadget state is 'suspended' even vbus is still there. > > And when the gadget goes to suspend or reset or disconnect state, we can > go to disable this wakeup source. > > At drivers/usb/gadget/composite.c, we can know the gadget's state. > Thanks very much for your suggestion, and apologies in the delay in response. I tried to study your suggestion and the code a little bit more, and while I liked your idea quite a bit, I also realised that for the case of letting the USB charger use cases, in gadget framework, there doesn't seem to be a way to get the USB_EVENT_CHARGER, since charger would likely not be a gadget. In this case, how'd we be able to enable / disable wakeup_source for charger events? If indeed we can't handle charger events in the way suggested by you, may I propose the following: - implement this in USB-phy as proposed in Kiran's original patch, - keep it disabled by default, and add a module param to enable/disable it - for no vbus case, use another event (USB_EVENT_ENUMERATED / USB_EVENT_NONE? ) to identify connect / disconnect? (OR, maybe don't do anything for such cases, since most likely the chipidea kind of implementations would handle it themselves?) Of course these are based on my limited reading of the USB code, so I'd be grateful if you'd let me know of any obvious gaps in my understanding! > -- > > Best Regards, > Peter Chen Best regards, Sumit. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 13 July 2015 at 12:30, Peter Chen <peter.chen@freescale.com> wrote: > On Mon, Jul 13, 2015 at 01:26:23PM +0530, Sumit Semwal wrote: >> Hi Peter, >> >> On 8 June 2015 at 14:02, Peter Chen <peter.chen@freescale.com> wrote: >> > On Mon, Jun 08, 2015 at 12:37:00PM +0530, Sumit Semwal wrote: >> >> H Peter, Felipe, >> >> >> >> On 14 January 2015 at 06:56, Peter Chen <peter.chen@freescale.com> wrote: >> >> > On Tue, Jan 13, 2015 at 10:18:02AM -0600, Felipe Balbi wrote: >> >> >> On Tue, Jan 13, 2015 at 04:02:20PM +0530, Kiran Raparthy wrote: >> >> >> > Hi Felipe, >> >> >> > >> >> >> > On 1 December 2014 at 11:09, Kiran Raparthy <kiran.kumar@linaro.org> wrote: >> >> >> > > Hi Felipe, >> >> >> > > >> >> >> > > On 25 November 2014 at 20:15, Felipe Balbi <balbi@ti.com> wrote: >> >> >> > >> On Tue, Nov 25, 2014 at 07:06:18AM +0000, Peter Chen wrote: >> >> >> > >>> >> >> >> > >>> > >> >> >> > >>> > usb: phy: hold wakeupsource when USB is enumerated in peripheral mode >> >> >> > >>> > >> >> >> > >>> > Some systems require a mechanism to prevent system to enter into suspend >> >> >> > >>> > state when USB is connected and enumerated in peripheral mode. >> >> >> > >>> > >> >> >> > >>> > This patch provides an interface to hold a wakeupsource to prevent suspend. >> >> >> > >>> > PHY drivers can use this interface when USB is connected and enumerated in >> >> >> > >>> > peripheral mode. >> >> >> > >>> > >> >> >> > >>> > A timed wakeupsource is temporarily held on USB disconnect events, to allow >> >> >> > >>> > the rest of the system to react to the USB disconnection (dropping host >> >> >> > >>> > sessions, updating charger status, etc.) prior to re-allowing suspend. >> >> >> > >>> > >> >> >> > >>> >> <snip> >> >> >> >> Kiran is unable to continue on this patch anymore, so despite my very >> >> limited usb experience, I would like to take this over and with your >> >> help, take it to closure. >> >> >> >> From what I understand, it might be possible to do this either at the >> >> usb controller driver (where it detects if it has enumerated in host >> >> mode or device mode) or in the extcon driver (where it detects VBUS >> >> etc..) - which would be a cleaner / more logical way to do it? >> >> >> >> Thanks for all your help! >> > >> > I added my suggestions below: >> > >> > My opinion is: if we need this feature, we should depend on gadget's >> > state, eg 'configured', not vbus level. The system suspend should be >> > allowed if the gadget state is 'suspended' even vbus is still there. >> > >> > And when the gadget goes to suspend or reset or disconnect state, we can >> > go to disable this wakeup source. >> > >> > At drivers/usb/gadget/composite.c, we can know the gadget's state. >> > >> Thanks very much for your suggestion, and apologies in the delay in response. >> >> I tried to study your suggestion and the code a little bit more, and >> while I liked your idea quite a bit, I also realised that for the case >> of letting the USB charger use cases, in gadget framework, there >> doesn't seem to be a way to get the USB_EVENT_CHARGER, since charger >> would likely not be a gadget. >> >> In this case, how'd we be able to enable / disable wakeup_source for >> charger events? > > We may not prevent the system entering system if it is a charger, isn't > it, so don't need to consider USB charger. > Thanks for your comments, Peter! From the Android code that I see, it seems that for a charger connect/disconnect, some systems might require some time to react to the change in power, and hence there's a timed-out wakeup event for USB charger cases. That;s where the consideration for USB chargers came from. >> >> If indeed we can't handle charger events in the way suggested by you, >> may I propose the following: >> >> - implement this in USB-phy as proposed in Kiran's original patch, >> - keep it disabled by default, and add a module param to enable/disable it >> - for no vbus case, use another event (USB_EVENT_ENUMERATED / >> USB_EVENT_NONE? ) to identify connect / disconnect? >> (OR, maybe don't do anything for such cases, since most likely >> the chipidea kind of implementations would handle it themselves?) >> > > In my opinion, we can do noop for wakeup source if it is a USB charger. > I think I misunderstood your comment here - do you mean for 'no vbus case (like chipidea)' do a noop for wakeup source? In the gadget framework, there doesn't seem to be a way to get to know if a USB charger is connected. >> Of course these are based on my limited reading of the USB code, so >> I'd be grateful if you'd let me know of any obvious gaps in my >> understanding! >> >> > -- >> > >> > Best Regards, >> > Peter Chen >> >> >> Best regards, >> Sumit. > > -- > > Best Regards, > Peter Chen Best regards, Sumit. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Hi Peter, On 20 July 2015 at 12:45, Peter Chen <peter.chen@freescale.com> wrote: > On Mon, Jul 20, 2015 at 01:18:35PM +0530, Sumit Semwal wrote: >> On 13 July 2015 at 12:30, Peter Chen <peter.chen@freescale.com> wrote: >> > On Mon, Jul 13, 2015 at 01:26:23PM +0530, Sumit Semwal wrote: >> >> Hi Peter, >> >> >> >> On 8 June 2015 at 14:02, Peter Chen <peter.chen@freescale.com> wrote: >> >> > On Mon, Jun 08, 2015 at 12:37:00PM +0530, Sumit Semwal wrote: >> >> >> H Peter, Felipe, >> >> >> >> >> >> On 14 January 2015 at 06:56, Peter Chen <peter.chen@freescale.com> wrote: >> >> >> > On Tue, Jan 13, 2015 at 10:18:02AM -0600, Felipe Balbi wrote: >> >> >> >> On Tue, Jan 13, 2015 at 04:02:20PM +0530, Kiran Raparthy wrote: >> >> >> >> > Hi Felipe, >> >> >> >> > >> >> >> >> > On 1 December 2014 at 11:09, Kiran Raparthy <kiran.kumar@linaro.org> wrote: >> >> >> >> > > Hi Felipe, >> >> >> >> > > >> >> >> >> > > On 25 November 2014 at 20:15, Felipe Balbi <balbi@ti.com> wrote: >> >> >> >> > >> On Tue, Nov 25, 2014 at 07:06:18AM +0000, Peter Chen wrote: >> >> >> >> > >>> >> >> >> >> > >>> > >> >> >> >> > >>> > usb: phy: hold wakeupsource when USB is enumerated in peripheral mode >> >> >> >> > >>> > >> >> >> >> > >>> > Some systems require a mechanism to prevent system to enter into suspend >> >> >> >> > >>> > state when USB is connected and enumerated in peripheral mode. >> >> >> >> > >>> > >> >> >> >> > >>> > This patch provides an interface to hold a wakeupsource to prevent suspend. >> >> >> >> > >>> > PHY drivers can use this interface when USB is connected and enumerated in >> >> >> >> > >>> > peripheral mode. >> >> >> >> > >>> > >> >> >> >> > >>> > A timed wakeupsource is temporarily held on USB disconnect events, to allow >> >> >> >> > >>> > the rest of the system to react to the USB disconnection (dropping host >> >> >> >> > >>> > sessions, updating charger status, etc.) prior to re-allowing suspend. >> >> >> >> > >>> > >> >> >> >> > >>> >> >> <snip> >> >> >> >> >> >> Kiran is unable to continue on this patch anymore, so despite my very >> >> >> limited usb experience, I would like to take this over and with your >> >> >> help, take it to closure. >> >> >> >> >> >> From what I understand, it might be possible to do this either at the >> >> >> usb controller driver (where it detects if it has enumerated in host >> >> >> mode or device mode) or in the extcon driver (where it detects VBUS >> >> >> etc..) - which would be a cleaner / more logical way to do it? >> >> >> >> >> >> Thanks for all your help! >> >> > >> >> > I added my suggestions below: >> >> > >> >> > My opinion is: if we need this feature, we should depend on gadget's >> >> > state, eg 'configured', not vbus level. The system suspend should be >> >> > allowed if the gadget state is 'suspended' even vbus is still there. >> >> > >> >> > And when the gadget goes to suspend or reset or disconnect state, we can >> >> > go to disable this wakeup source. >> >> > >> >> > At drivers/usb/gadget/composite.c, we can know the gadget's state. >> >> > >> >> Thanks very much for your suggestion, and apologies in the delay in response. >> >> >> >> I tried to study your suggestion and the code a little bit more, and >> >> while I liked your idea quite a bit, I also realised that for the case >> >> of letting the USB charger use cases, in gadget framework, there >> >> doesn't seem to be a way to get the USB_EVENT_CHARGER, since charger >> >> would likely not be a gadget. >> >> >> >> In this case, how'd we be able to enable / disable wakeup_source for >> >> charger events? >> > >> > We may not prevent the system entering system if it is a charger, isn't >> > it, so don't need to consider USB charger. >> > >> Thanks for your comments, Peter! >> From the Android code that I see, it seems that for a charger >> connect/disconnect, some systems might require some time to react to >> the change in power, and hence there's a timed-out wakeup event for >> USB charger cases. That;s where the consideration for USB chargers >> came from. > > Current udc core has an API usb_gadget_set_state set its state > according to usb ch9. For this wakeup source case, if the peripheral > has been configured, it can hold wakeup source. Otherise, just have > a timeout wake lock. Thank you for your kind hint. Let me toy with this change and update. > Below are some reference code: > > diff --git a/drivers/usb/gadget/udc/udc-core.c > b/drivers/usb/gadget/udc/udc-core.c > index d69c355..018f534 100644 > --- a/drivers/usb/gadget/udc/udc-core.c > +++ b/drivers/usb/gadget/udc/udc-core.c > > @@ -136,6 +138,16 @@ static void usb_gadget_state_work(struct > work_struct *work) > > if (udc) { > sysfs_notify(&udc->dev.kobj, NULL, "state"); > switch (gadget->state) { > case USB_STATE_CONFIGURED: > __pm_stay_awake(&x->wsource); > break; > default: > __pm_wakeup_event(&x->wsource, > USB_DEFAULT_WAKEUP_SRC_TIMEOUT); > break; > } > } > > > -- > > Best Regards, > Peter Chen Best regards, Sumit. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c index b4066a0..8c87bc3 100644 --- a/drivers/usb/phy/phy.c +++ b/drivers/usb/phy/phy.c @@ -331,6 +331,7 @@ int usb_add_phy(struct usb_phy *x, enum usb_phy_type type) int ret = 0; unsigned long flags; struct usb_phy *phy; + char wsource_name[40]; if (x->type != USB_PHY_TYPE_UNDEFINED) { dev_err(x->dev, "not accepting initialized PHY %s\n", x->label); @@ -353,6 +354,10 @@ int usb_add_phy(struct usb_phy *x, enum usb_phy_type type) x->type = type; list_add_tail(&x->head, &phy_list); + snprintf(wsource_name, sizeof(wsource_name), "vbus-%s", + dev_name(x->dev)); + wakeup_source_init(&x->wsource, wsource_name); + out: spin_unlock_irqrestore(&phy_lock, flags); return ret; @@ -404,6 +409,7 @@ void usb_remove_phy(struct usb_phy *x) spin_lock_irqsave(&phy_lock, flags); if (x) { + wakeup_source_trash(&x->wsource); list_for_each_entry(phy_bind, &phy_bind_list, list) if (phy_bind->phy == x) phy_bind->phy = NULL; @@ -448,13 +454,32 @@ int usb_bind_phy(const char *dev_name, u8 index, EXPORT_SYMBOL_GPL(usb_bind_phy); /** - * usb_phy_set_event - set event to phy event + * usb_phy_set_event - set event to phy event and + * hold/temporarily hold wakeupsource * @x: the phy returned by usb_get_phy(); * - * This sets event to phy event + * This holds per-PHY wakeupsource/timed wakeupsource */ void usb_phy_set_event(struct usb_phy *x, unsigned long event) { + x->last_event = event; + + switch (event) { + case USB_EVENT_ENUMERATED: + __pm_stay_awake(&x->wsource); + break; + + case USB_EVENT_NONE: + case USB_EVENT_ID: + case USB_EVENT_VBUS: + case USB_EVENT_CHARGER: + __pm_wakeup_event(&x->wsource, + USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT); + break; + + default: + break; + } } EXPORT_SYMBOL_GPL(usb_phy_set_event); diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h index f499c23..63a56bf 100644 --- a/include/linux/usb/phy.h +++ b/include/linux/usb/phy.h @@ -12,6 +12,8 @@ #include <linux/notifier.h> #include <linux/usb.h> +#define USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT msecs_to_jiffies(2000) + enum usb_phy_interface { USBPHY_INTERFACE_MODE_UNKNOWN, USBPHY_INTERFACE_MODE_UTMI, @@ -88,6 +90,9 @@ struct usb_phy { /* for notification of usb_phy_events */ struct atomic_notifier_head notifier; + /* wakeup source */ + struct wakeup_source wsource; + /* to pass extra port status to the root hub */ u16 port_status; u16 port_change;
usb: phy: hold wakeupsource when USB is enumerated in peripheral mode Some systems require a mechanism to prevent system to enter into suspend state when USB is connected and enumerated in peripheral mode. This patch provides an interface to hold a wakeupsource to prevent suspend. PHY drivers can use this interface when USB is connected and enumerated in peripheral mode. A timed wakeupsource is temporarily held on USB disconnect events, to allow the rest of the system to react to the USB disconnection (dropping host sessions, updating charger status, etc.) prior to re-allowing suspend. Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-kernel@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: Android Kernel Team <kernel-team@android.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Arve Hjønnevåg <arve@android.com> Cc: Benoit Goby <benoit@android.com> [Original patch in Android from Todd] Cc: Todd Poynor <toddpoynor@google.com> Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org> --- drivers/usb/phy/phy.c | 29 +++++++++++++++++++++++++++-- include/linux/usb/phy.h | 5 +++++ 2 files changed, 32 insertions(+), 2 deletions(-)