diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 2057d91d83360ddb614ffaeeb174883c1759f7cf..dadd1e8dfe09ded9d28e541099d43f582707596c 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -284,7 +284,7 @@ static int usb_probe_interface(struct device *dev) struct usb_device *udev = interface_to_usbdev(intf); const struct usb_device_id *id; int error = -ENODEV; - int lpm_disable_error; + int lpm_disable_error = -ENODEV; dev_dbg(dev, "%s\n", __func__); @@ -336,12 +336,14 @@ static int usb_probe_interface(struct device *dev) * setting during probe, that should also be fine. usb_set_interface() * will attempt to disable LPM, and fail if it can't disable it. */ - lpm_disable_error = usb_unlocked_disable_lpm(udev); - if (lpm_disable_error && driver->disable_hub_initiated_lpm) { - dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.", - __func__, driver->name); - error = lpm_disable_error; - goto err; + if (driver->disable_hub_initiated_lpm) { + lpm_disable_error = usb_unlocked_disable_lpm(udev); + if (lpm_disable_error) { + dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n.", + __func__, driver->name); + error = lpm_disable_error; + goto err; + } } /* Carry out a deferred switch to altsetting 0 */ @@ -391,7 +393,8 @@ static int usb_unbind_interface(struct device *dev) struct usb_interface *intf = to_usb_interface(dev); struct usb_host_endpoint *ep, **eps = NULL; struct usb_device *udev; - int i, j, error, r, lpm_disable_error; + int i, j, error, r; + int lpm_disable_error = -ENODEV; intf->condition = USB_INTERFACE_UNBINDING; @@ -399,12 +402,13 @@ static int usb_unbind_interface(struct device *dev) udev = interface_to_usbdev(intf); error = usb_autoresume_device(udev); - /* Hub-initiated LPM policy may change, so attempt to disable LPM until + /* If hub-initiated LPM policy may change, attempt to disable LPM until * the driver is unbound. If LPM isn't disabled, that's fine because it * wouldn't be enabled unless all the bound interfaces supported * hub-initiated LPM. */ - lpm_disable_error = usb_unlocked_disable_lpm(udev); + if (driver->disable_hub_initiated_lpm) + lpm_disable_error = usb_unlocked_disable_lpm(udev); /* * Terminate all URBs for this interface unless the driver @@ -505,7 +509,7 @@ int usb_driver_claim_interface(struct usb_driver *driver, struct device *dev; struct usb_device *udev; int retval = 0; - int lpm_disable_error; + int lpm_disable_error = -ENODEV; if (!iface) return -ENODEV; @@ -526,12 +530,14 @@ int usb_driver_claim_interface(struct usb_driver *driver, iface->condition = USB_INTERFACE_BOUND; - /* Disable LPM until this driver is bound. */ - lpm_disable_error = usb_unlocked_disable_lpm(udev); - if (lpm_disable_error && driver->disable_hub_initiated_lpm) { - dev_err(&iface->dev, "%s Failed to disable LPM for driver %s\n.", - __func__, driver->name); - return -ENOMEM; + /* See the comment about disabling LPM in usb_probe_interface(). */ + if (driver->disable_hub_initiated_lpm) { + lpm_disable_error = usb_unlocked_disable_lpm(udev); + if (lpm_disable_error) { + dev_err(&iface->dev, "%s Failed to disable LPM for driver %s\n.", + __func__, driver->name); + return -ENOMEM; + } } /* Claimed interfaces are initially inactive (suspended) and diff --git a/include/linux/usb.h b/include/linux/usb.h index 01b6c61cf9bb7e0959a7fc9ab50f49ca2fc89440..eba1f10e8cfdac7c0cc142db6b72e031f9f30196 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1068,7 +1068,7 @@ struct usbdrv_wrap { * for interfaces bound to this driver. * @soft_unbind: if set to 1, the USB core will not kill URBs and disable * endpoints before calling the driver's disconnect method. - * @disable_hub_initiated_lpm: if set to 0, the USB core will not allow hubs + * @disable_hub_initiated_lpm: if set to 1, the USB core will not allow hubs * to initiate lower power link state transitions when an idle timeout * occurs. Device-initiated USB 3.0 link PM will still be allowed. *