diff --git a/drivers/media/usb/gspca/sunplus.c b/drivers/media/usb/gspca/sunplus.c
index f4a4222f0d2e..bfac15d6c958 100644
--- a/drivers/media/usb/gspca/sunplus.c
+++ b/drivers/media/usb/gspca/sunplus.c
@@ -242,6 +242,10 @@ static void reg_r(struct gspca_dev *gspca_dev,
 		gspca_err(gspca_dev, "reg_r: buffer overflow\n");
 		return;
 	}
+	if (len == 0) {
+		gspca_err(gspca_dev, "reg_r: zero-length read\n");
+		return;
+	}
 	if (gspca_dev->usb_err < 0)
 		return;
 	ret = usb_control_msg(gspca_dev->dev,
@@ -250,7 +254,7 @@ static void reg_r(struct gspca_dev *gspca_dev,
 			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 			0,		/* value */
 			index,
-			len ? gspca_dev->usb_buf : NULL, len,
+			gspca_dev->usb_buf, len,
 			500);
 	if (ret < 0) {
 		pr_err("reg_r err %d\n", ret);
@@ -727,7 +731,7 @@ static int sd_start(struct gspca_dev *gspca_dev)
 		case MegaImageVI:
 			reg_w_riv(gspca_dev, 0xf0, 0, 0);
 			spca504B_WaitCmdStatus(gspca_dev);
-			reg_r(gspca_dev, 0xf0, 4, 0);
+			reg_w_riv(gspca_dev, 0xf0, 4, 0);
 			spca504B_WaitCmdStatus(gspca_dev);
 			break;
 		default: