diff options
Diffstat (limited to 'drivers/usb/core/hub.c')
| -rw-r--r-- | drivers/usb/core/hub.c | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 8e65f7a237e4..90b8d43c6b33 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -836,6 +836,13 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id) desc = intf->cur_altsetting; hdev = interface_to_usbdev(intf); +#ifdef CONFIG_USB_OTG_BLACKLIST_HUB + if (hdev->parent) { + dev_warn(&intf->dev, "ignoring external hub\n"); + return -ENODEV; + } +#endif + /* Some hubs have a subclass of 1, which AFAICT according to the */ /* specs is not defined, but it works */ if ((desc->desc.bInterfaceSubClass != 0) && @@ -1022,7 +1029,6 @@ void usb_set_device_state(struct usb_device *udev, recursively_mark_NOTATTACHED(udev); spin_unlock_irqrestore(&device_state_lock, flags); } -EXPORT_SYMBOL(usb_set_device_state); #ifdef CONFIG_PM @@ -1162,19 +1168,9 @@ static inline const char *plural(int n) static int choose_configuration(struct usb_device *udev) { int i; - u16 devstatus; - int bus_powered; int num_configs; struct usb_host_config *c, *best; - /* If this fails, assume the device is bus-powered */ - devstatus = 0; - usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus); - le16_to_cpus(&devstatus); - bus_powered = ((devstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0); - dev_dbg(&udev->dev, "device is %s-powered\n", - bus_powered ? "bus" : "self"); - best = NULL; c = udev->config; num_configs = udev->descriptor.bNumConfigurations; @@ -1191,6 +1187,19 @@ static int choose_configuration(struct usb_device *udev) * similar errors in their descriptors. If the next test * were allowed to execute, such configurations would always * be rejected and the devices would not work as expected. + * In the meantime, we run the risk of selecting a config + * that requires external power at a time when that power + * isn't available. It seems to be the lesser of two evils. + * + * Bugzilla #6448 reports a device that appears to crash + * when it receives a GET_DEVICE_STATUS request! We don't + * have any other way to tell whether a device is self-powered, + * but since we don't use that information anywhere but here, + * the call has been removed. + * + * Maybe the GET_DEVICE_STATUS call and the test below can + * be reinstated when device firmwares become more reliable. + * Don't hold your breath. */ #if 0 /* Rule out self-powered configs for a bus-powered device */ |