X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fusb%2Fcore%2Fdriver.c;fp=kernel%2Fdrivers%2Fusb%2Fcore%2Fdriver.c;h=dadd1e8dfe09ded9d28e541099d43f582707596c;hb=52f993b8e89487ec9ee15a7fb4979e0f09a45b27;hp=56593a9a87268cc0f6d8181cb5f8021c252b457b;hpb=c189ccac5702322ed843fe17057035b7222a59b6;p=kvmfornfv.git

diff --git a/kernel/drivers/usb/core/driver.c b/kernel/drivers/usb/core/driver.c
index 56593a9a8..dadd1e8df 100644
--- a/kernel/drivers/usb/core/driver.c
+++ b/kernel/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
@@ -502,11 +506,15 @@ static int usb_unbind_interface(struct device *dev)
 int usb_driver_claim_interface(struct usb_driver *driver,
 				struct usb_interface *iface, void *priv)
 {
-	struct device *dev = &iface->dev;
+	struct device *dev;
 	struct usb_device *udev;
 	int retval = 0;
-	int lpm_disable_error;
+	int lpm_disable_error = -ENODEV;
 
+	if (!iface)
+		return -ENODEV;
+
+	dev = &iface->dev;
 	if (dev->driver)
 		return -EBUSY;
 
@@ -522,12 +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