cx25840: treat firmware data as const

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Tyler Trafford <ttrafford@gmail.com>
Acked-by: Mike Isely <isely@pobox.com>
diff --git a/drivers/media/video/cx25840/cx25840-firmware.c b/drivers/media/video/cx25840/cx25840-firmware.c
index 620d295..8d489a4 100644
--- a/drivers/media/video/cx25840/cx25840-firmware.c
+++ b/drivers/media/video/cx25840/cx25840-firmware.c
@@ -79,7 +79,7 @@
 	return 0;
 }
 
-static int fw_write(struct i2c_client *client, u8 *data, int size)
+static int fw_write(struct i2c_client *client, const u8 *data, int size)
 {
 	if (i2c_master_send(client, data, size) < size) {
 		v4l_err(client, "firmware load i2c failure\n");
@@ -93,7 +93,8 @@
 {
 	struct cx25840_state *state = i2c_get_clientdata(client);
 	const struct firmware *fw = NULL;
-	u8 buffer[4], *ptr;
+	u8 buffer[FWSEND];
+	const u8 *ptr;
 	int size, retval;
 
 	if (state->is_cx23885)
@@ -108,29 +109,23 @@
 
 	buffer[0] = 0x08;
 	buffer[1] = 0x02;
-	buffer[2] = fw->data[0];
-	buffer[3] = fw->data[1];
-	retval = fw_write(client, buffer, 4);
 
-	if (retval < 0) {
-		release_firmware(fw);
-		return retval;
-	}
-
-	size = fw->size - 2;
+	size = fw->size;
 	ptr = fw->data;
 	while (size > 0) {
-		ptr[0] = 0x08;
-		ptr[1] = 0x02;
-		retval = fw_write(client, ptr, min(FWSEND, size + 2));
+		int len = min(FWSEND - 2, size);
+
+		memcpy(buffer + 2, ptr, len);
+
+		retval = fw_write(client, buffer, len + 2);
 
 		if (retval < 0) {
 			release_firmware(fw);
 			return retval;
 		}
 
-		size -= FWSEND - 2;
-		ptr += FWSEND - 2;
+		size -= len;
+		ptr += len;
 	}
 
 	end_fw_load(client);