diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 4225d5e72131..8e64adf8e4d5 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -1025,6 +1026,49 @@ static int register_root_hub(struct usb_hcd *hcd) return retval; } +/* + * usb_hcd_start_port_resume - a root-hub port is sending a resume signal + * @bus: the bus which the root hub belongs to + * @portnum: the port which is being resumed + * + * HCDs should call this function when they know that a resume signal is + * being sent to a root-hub port. The root hub will be prevented from + * going into autosuspend until usb_hcd_end_port_resume() is called. + * + * The bus's private lock must be held by the caller. + */ +void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum) +{ + unsigned bit = 1 << portnum; + + if (!(bus->resuming_ports & bit)) { + bus->resuming_ports |= bit; + pm_runtime_get_noresume(&bus->root_hub->dev); + } +} +EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume); + +/* + * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal + * @bus: the bus which the root hub belongs to + * @portnum: the port which is being resumed + * + * HCDs should call this function when they know that a resume signal has + * stopped being sent to a root-hub port. The root hub will be allowed to + * autosuspend again. + * + * The bus's private lock must be held by the caller. + */ +void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum) +{ + unsigned bit = 1 << portnum; + + if (bus->resuming_ports & bit) { + bus->resuming_ports &= ~bit; + pm_runtime_put_noidle(&bus->root_hub->dev); + } +} +EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume); /*-------------------------------------------------------------------------*/ diff --git a/include/linux/usb.h b/include/linux/usb.h index 689b14b26c8d..4d22d0f6167a 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -357,6 +357,8 @@ struct usb_bus { int bandwidth_int_reqs; /* number of Interrupt requests */ int bandwidth_isoc_reqs; /* number of Isoc. requests */ + unsigned resuming_ports; /* bit array: resuming root-hub ports */ + #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE) struct mon_bus *mon_bus; /* non-null when associated */ int monitored; /* non-zero when monitored */ diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index 608050b2545f..0a78df5f6cfd 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -430,6 +430,9 @@ extern void usb_hcd_poll_rh_status(struct usb_hcd *hcd); extern void usb_wakeup_notification(struct usb_device *hdev, unsigned int portnum); +extern void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum); +extern void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum); + /* The D0/D1 toggle bits ... USE WITH CAUTION (they're almost hcd-internal) */ #define usb_gettoggle(dev, ep, out) (((dev)->toggle[out] >> (ep)) & 1) #define usb_dotoggle(dev, ep, out) ((dev)->toggle[out] ^= (1 << (ep)))