[PATCH 4/7] Input: ALPS - Remove assumptions about packet size

[Seth Forshee <seth.forshee@canonical.com>]

In preparation for version 4 protocol support, which has 8-byte
data packets, remove all hard-coded assumptions about packet size
and use psmouse->pktsize instead.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
---
 drivers/input/mouse/alps.c |   27 ++++++++++++++++++---------
 1 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 572cb21..14d1f64 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -315,7 +315,7 @@ static void alps_flush_packet(unsigned long data)
 
 	serio_pause_rx(psmouse->ps2dev.serio);
 
-	if (psmouse->pktcnt == 6) {
+	if (psmouse->pktcnt == psmouse->pktsize) {
 
 		/*
 		 * We did not any more data in reasonable amount of time.
@@ -365,15 +365,15 @@ static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
 		return PSMOUSE_BAD_DATA;
 	}
 
-	/* Bytes 2 - 6 should have 0 in the highest bit */
-	if (psmouse->pktcnt >= 2 && psmouse->pktcnt <= 6 &&
+	/* Bytes 2 - pktsize should have 0 in the highest bit */
+	if (psmouse->pktcnt >= 2 && psmouse->pktcnt <= psmouse->pktsize &&
 	    (psmouse->packet[psmouse->pktcnt - 1] & 0x80)) {
 		dbg("refusing packet[%i] = %x\n",
 		    psmouse->pktcnt - 1, psmouse->packet[psmouse->pktcnt - 1]);
 		return PSMOUSE_BAD_DATA;
 	}
 
-	if (psmouse->pktcnt == 6) {
+	if (psmouse->pktcnt == psmouse->pktsize) {
 		alps_process_packet(psmouse);
 		return PSMOUSE_FULL_PACKET;
 	}
@@ -531,8 +531,13 @@ static int alps_tap_mode(struct psmouse *psmouse, int enable)
 static int alps_poll(struct psmouse *psmouse)
 {
 	struct alps_data *priv = psmouse->private;
-	unsigned char buf[6];
+	unsigned char *buf;
 	bool poll_failed;
+	int ret = -1;
+
+	buf = kmalloc(psmouse->pktsize, GFP_KERNEL);
+	if (!buf)
+		return -1;
 
 	if (priv->i->flags & ALPS_PASS)
 		alps_passthrough_mode(psmouse, true);
@@ -544,18 +549,22 @@ static int alps_poll(struct psmouse *psmouse)
 		alps_passthrough_mode(psmouse, false);
 
 	if (poll_failed || (buf[0] & priv->i->mask0) != priv->i->byte0)
-		return -1;
+		goto out;
 
 	if ((psmouse->badbyte & 0xc8) == 0x08) {
 /*
  * Poll the track stick ...
  */
 		if (ps2_command(&psmouse->ps2dev, buf, PSMOUSE_CMD_POLL | (3 << 8)))
-			return -1;
+			goto out;
 	}
 
-	memcpy(psmouse->packet, buf, sizeof(buf));
-	return 0;
+	memcpy(psmouse->packet, buf, psmouse->pktsize);
+	ret = 0;
+
+out:
+	kfree(buf);
+	return ret;
 }
 
 static int alps_hw_init(struct psmouse *psmouse)
-- 
1.7.5.4