Input: pegasus_notetaker - handle usb control msg errors

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c
index 805afe3..78dbf39 100644
--- a/drivers/input/tablet/pegasus_notetaker.c
+++ b/drivers/input/tablet/pegasus_notetaker.c
@@ -80,15 +80,16 @@
 	struct work_struct init;
 };
 
-static void pegasus_control_msg(struct pegasus *pegasus, u8 *data, int len)
+static int pegasus_control_msg(struct pegasus *pegasus, u8 *data, int len)
 {
 	const int sizeof_buf = len + 2;
 	int result;
+	int error;
 	u8 *cmd_buf;
 
 	cmd_buf = kmalloc(sizeof_buf, GFP_KERNEL);
 	if (!cmd_buf)
-		return;
+		return -ENOMEM;
 
 	cmd_buf[0] = NOTETAKER_REPORT_ID;
 	cmd_buf[1] = len;
@@ -101,17 +102,23 @@
 				 0, 0, cmd_buf, sizeof_buf,
 				 USB_CTRL_SET_TIMEOUT);
 
-	if (result != sizeof_buf)
-		dev_err(&pegasus->usbdev->dev, "control msg error\n");
-
 	kfree(cmd_buf);
+
+	if (unlikely(result != sizeof_buf)) {
+		error = result < 0 ? result : -EIO;
+		dev_err(&pegasus->usbdev->dev, "control msg error: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
 }
 
-static void pegasus_set_mode(struct pegasus *pegasus, u8 mode, u8 led)
+static int pegasus_set_mode(struct pegasus *pegasus, u8 mode, u8 led)
 {
 	u8 cmd[] = { NOTETAKER_SET_CMD, NOTETAKER_SET_MODE, led, mode };
 
-	pegasus_control_msg(pegasus, cmd, sizeof(cmd));
+	return pegasus_control_msg(pegasus, cmd, sizeof(cmd));
 }
 
 static void pegasus_parse_packet(struct pegasus *pegasus)
@@ -191,8 +198,12 @@
 static void pegasus_init(struct work_struct *work)
 {
 	struct pegasus *pegasus = container_of(work, struct pegasus, init);
+	int error;
 
-	pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
+	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
+	if (error)
+		dev_err(&pegasus->usbdev->dev, "pegasus_set_mode error: %d\n",
+			error);
 }
 
 static int pegasus_open(struct input_dev *dev)
@@ -208,7 +219,7 @@
 	if (usb_submit_urb(pegasus->irq, GFP_KERNEL))
 		retval = -EIO;
 
-	pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
+	retval = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
 
 	usb_autopm_put_interface(pegasus->intf);