staging: usbip: let client choose device configuration

Since usbip-host is now a device driver and the client
has full access to the shared device, it makes sense to
let the client choose device configuration.
Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/usbip/stub_dev.c

@@ -337,7 +337,7 @@ static int stub_probe(struct usb_device *udev)
 {
 	struct stub_device *sdev = NULL;
 	const char *udev_busid = dev_name(&udev->dev);
-	int err = 0, config;
+	int err = 0;
 	struct bus_id_priv *busid_priv;
 
 	dev_dbg(&udev->dev, "Enter\n");
@@ -383,14 +383,6 @@ static int stub_probe(struct usb_device *udev)
 
 	busid_priv->shutdown_busid = 0;
 
-	config = usb_choose_configuration(udev);
-	if (config >= 0) {
-		err = usb_set_configuration(udev, config);
-		if (err && err != -ENODEV)
-			dev_err(&udev->dev, "can't set config #%d, error %d\n",
-				config, err);
-	}
-
 	/* set private data to usb_device */
 	dev_set_drvdata(&udev->dev, sdev);
 	busid_priv->sdev = sdev;

drivers/staging/usbip/stub_rx.c

@@ -142,31 +142,19 @@ static int tweak_set_interface_cmd(struct urb *urb)
 
 static int tweak_set_configuration_cmd(struct urb *urb)
 {
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+	struct stub_device *sdev = priv->sdev;
 	struct usb_ctrlrequest *req;
 	__u16 config;
+	int err;
 
 	req = (struct usb_ctrlrequest *) urb->setup_packet;
 	config = le16_to_cpu(req->wValue);
 
-	/*
-	 * I have never seen a multi-config device. Very rare.
-	 * For most devices, this will be called to choose a default
-	 * configuration only once in an initialization phase.
-	 *
-	 * set_configuration may change a device configuration and its device
-	 * drivers will be unbound and assigned for a new device configuration.
-	 * This means this usbip driver will be also unbound when called, then
-	 * eventually reassigned to the device as far as driver matching
-	 * condition is kept.
-	 *
-	 * Unfortunately, an existing usbip connection will be dropped
-	 * due to this driver unbinding. So, skip here.
-	 * A user may need to set a special configuration value before
-	 * exporting the device.
-	 */
-	dev_info(&urb->dev->dev, "usb_set_configuration %d to %s... skip!\n",
-		 config, dev_name(&urb->dev->dev));
-
+	err = usb_set_configuration(sdev->udev, config);
+	if (err && err != -ENODEV)
+		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
+			config, err);
 	return 0;
 }