usb_rcvctrlpipe(serial->dev, 0),
0xfe, 0xc0, 0, reg,
buf, 1, ARK_TIMEOUT);
- if (result < 0)
+ if (result < 1) {
+ dev_err(&serial->interface->dev,
+ "failed to read register %u: %d\n",
+ reg, result);
+ if (result >= 0)
+ result = -EIO;
+
return result;
- else
- return buf[0];
+ }
+
+ return buf[0];
}
static inline int calc_divisor(int bps)