[media] lirc: make transmit interface consistent

All lirc drivers that can transmit, return EINVAL when they are passed
more than IR data than they can send. That is, except for two drivers
which I touched.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

Documentation/DocBook/media/v4l/lirc_device_interface.xml

@@ -46,7 +46,9 @@ describing an IR signal are read from the chardev.</para>
 values. Pulses and spaces are only marked implicitly by their position. The
 data must start and end with a pulse, therefore, the data must always include
 an uneven number of samples. The write function must block until the data has
-been transmitted by the hardware.</para>
+been transmitted by the hardware. If more data is provided than the hardware
+can send, the driver returns EINVAL.</para>
+
 </section>
 
 <section id="lirc_ioctl">

drivers/media/rc/iguanair.c

@@ -364,8 +364,8 @@ static int iguanair_tx(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 		periods = DIV_ROUND_CLOSEST(txbuf[i] * ir->carrier, 1000000);
 		bytes = DIV_ROUND_UP(periods, 127);
 		if (size + bytes > ir->bufsize) {
-			count = i;
-			break;
+			rc = -EINVAL;
+			goto out;
 		}
 		while (periods > 127) {
 			ir->packet->payload[size++] = 127 | space;

drivers/media/rc/redrat3.c

@@ -762,7 +762,8 @@ static int redrat3_transmit_ir(struct rc_dev *rcdev, unsigned *txbuf,
 		return -EAGAIN;
 	}
 
-	count = min_t(unsigned, count, RR3_MAX_SIG_SIZE - RR3_TX_TRAILER_LEN);
+	if (count > RR3_MAX_SIG_SIZE - RR3_TX_TRAILER_LEN)
+		return -EINVAL;
 
 	/* rr3 will disable rc detector on transmit */
 	rr3->transmitting = true;
@@ -801,8 +802,8 @@ static int redrat3_transmit_ir(struct rc_dev *rcdev, unsigned *txbuf,
 						&irdata->lens[curlencheck]);
 				curlencheck++;
 			} else {
-				count = i - 1;
-				break;
+				ret = -EINVAL;
+				goto out;
 			}
 		}
 		irdata->sigdata[i] = lencheck;