USB: fixed bug in usbsevseg using USB autosuspend incorrectly

This patch fixes a bug with the usbsevseg driver which assumed that USB
autosuspend will always be used.

Signed-off-by: Harrison Metzger <harrisonmetz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/misc/usbsevseg.c

@@ -49,6 +49,7 @@ struct usb_sevsegdev {
 	u16 textlength;
 
 	u8 shadow_power; /* for PM */
+	u8 has_interface_pm;
 };
 
 /* sysfs_streq can't replace this completely
@@ -68,12 +69,16 @@ static void update_display_powered(struct usb_sevsegdev *mydev)
 {
 	int rc;
 
-	if (!mydev->shadow_power && mydev->powered) {
+	if (mydev->powered && !mydev->has_interface_pm) {
 		rc = usb_autopm_get_interface(mydev->intf);
 		if (rc < 0)
 			return;
+		mydev->has_interface_pm = 1;
 	}
 
+	if (mydev->shadow_power != 1)
+		return;
+
 	rc = usb_control_msg(mydev->udev,
 			usb_sndctrlpipe(mydev->udev, 0),
 			0x12,
@@ -86,8 +91,10 @@ static void update_display_powered(struct usb_sevsegdev *mydev)
 	if (rc < 0)
 		dev_dbg(&mydev->udev->dev, "power retval = %d\n", rc);
 
-	if (mydev->shadow_power && !mydev->powered)
+	if (!mydev->powered && mydev->has_interface_pm) {
 		usb_autopm_put_interface(mydev->intf);
+		mydev->has_interface_pm = 0;
+	}
 }
 
 static void update_display_mode(struct usb_sevsegdev *mydev)
@@ -351,6 +358,10 @@ static int sevseg_probe(struct usb_interface *interface,
 	mydev->intf = interface;
 	usb_set_intfdata(interface, mydev);
 
+	/* PM */
+	mydev->shadow_power = 1; /* currently active */
+	mydev->has_interface_pm = 0; /* have not issued autopm_get */
+
 	/*set defaults */
 	mydev->textmode = 0x02; /* ascii mode */
 	mydev->mode_msb = 0x06; /* 6 characters */