diff options
| -rw-r--r-- | drivers/usb/core/usb.c | 33 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-hub.c | 16 | ||||
| -rw-r--r-- | include/linux/usb.h | 1 |
3 files changed, 50 insertions, 0 deletions
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index b10da720f2b4..7dad603dde43 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -209,6 +209,39 @@ struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) } EXPORT_SYMBOL_GPL(usb_find_interface); +struct each_dev_arg { + void *data; + int (*fn)(struct usb_device *, void *); +}; + +static int __each_dev(struct device *dev, void *data) +{ + struct each_dev_arg *arg = (struct each_dev_arg *)data; + + /* There are struct usb_interface on the same bus, filter them out */ + if (!is_usb_device(dev)) + return 0; + + return arg->fn(container_of(dev, struct usb_device, dev), arg->data); +} + +/** + * usb_for_each_dev - iterate over all USB devices in the system + * @data: data pointer that will be handed to the callback function + * @fn: callback function to be called for each USB device + * + * Iterate over all USB devices and call @fn for each, passing it @data. If it + * returns anything other than 0, we break the iteration prematurely and return + * that value. + */ +int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)) +{ + struct each_dev_arg arg = {data, fn}; + + return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev); +} +EXPORT_SYMBOL_GPL(usb_for_each_dev); + /** * usb_release_dev - free a usb device structure when all users of it are finished. * @dev: device that's been disconnected diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 9ab4a4d9768a..b2f64506840b 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -42,6 +42,12 @@ static int ehci_hub_control( u16 wLength ); +static int persist_enabled_on_companion(struct usb_device *udev, void *unused) +{ + return !udev->maxchild && udev->persist_enabled && + udev->bus->root_hub->speed < USB_SPEED_HIGH; +} + /* After a power loss, ports that were owned by the companion must be * reset so that the companion can still own them. */ @@ -56,6 +62,16 @@ static void ehci_handover_companion_ports(struct ehci_hcd *ehci) if (!ehci->owned_ports) return; + /* + * USB 1.1 devices are mostly HIDs, which don't need to persist across + * suspends. If we ensure that none of our companion's devices have + * persist_enabled (by looking through all USB 1.1 buses in the system), + * we can skip this and avoid slowing resume down. Devices without + * persist will just get reenumerated shortly after resume anyway. + */ + if (!usb_for_each_dev(NULL, persist_enabled_on_companion)) + return; + /* Make sure the ports are powered */ port = HCS_N_PORTS(ehci->hcs_params); while (port--) { diff --git a/include/linux/usb.h b/include/linux/usb.h index a0bee5a28d1a..b424e5318f20 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -717,6 +717,7 @@ const struct usb_device_id *usb_match_id(struct usb_interface *interface, extern int usb_match_one_id(struct usb_interface *interface, const struct usb_device_id *id); +extern int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)); extern struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor); extern struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, |