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path: root/drivers/input/mouse/alps.c
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Diffstat (limited to 'drivers/input/mouse/alps.c')
-rw-r--r--drivers/input/mouse/alps.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 2b0ae8cc8e51..d125a019383f 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -1156,7 +1156,13 @@ static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
{
struct alps_data *priv = psmouse->private;
- if ((psmouse->packet[0] & 0xc8) == 0x08) { /* PS/2 packet */
+ /*
+ * Check if we are dealing with a bare PS/2 packet, presumably from
+ * a device connected to the external PS/2 port. Because bare PS/2
+ * protocol does not have enough constant bits to self-synchronize
+ * properly we only do this if the device is fully synchronized.
+ */
+ if (!psmouse->out_of_sync_cnt && (psmouse->packet[0] & 0xc8) == 0x08) {
if (psmouse->pktcnt == 3) {
alps_report_bare_ps2_packet(psmouse, psmouse->packet,
true);
@@ -1180,12 +1186,27 @@ static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
}
/* Bytes 2 - pktsize should have 0 in the highest bit */
- if ((priv->proto_version < ALPS_PROTO_V5) &&
+ if (priv->proto_version < ALPS_PROTO_V5 &&
psmouse->pktcnt >= 2 && psmouse->pktcnt <= psmouse->pktsize &&
(psmouse->packet[psmouse->pktcnt - 1] & 0x80)) {
psmouse_dbg(psmouse, "refusing packet[%i] = %x\n",
psmouse->pktcnt - 1,
psmouse->packet[psmouse->pktcnt - 1]);
+
+ if (priv->proto_version == ALPS_PROTO_V3 &&
+ psmouse->pktcnt == psmouse->pktsize) {
+ /*
+ * Some Dell boxes, such as Latitude E6440 or E7440
+ * with closed lid, quite often smash last byte of
+ * otherwise valid packet with 0xff. Given that the
+ * next packet is very likely to be valid let's
+ * report PSMOUSE_FULL_PACKET but not process data,
+ * rather than reporting PSMOUSE_BAD_DATA and
+ * filling the logs.
+ */
+ return PSMOUSE_FULL_PACKET;
+ }
+
return PSMOUSE_BAD_DATA;
}
@@ -2389,6 +2410,9 @@ int alps_init(struct psmouse *psmouse)
/* We are having trouble resyncing ALPS touchpads so disable it for now */
psmouse->resync_time = 0;
+ /* Allow 2 invalid packets without resetting device */
+ psmouse->resetafter = psmouse->pktsize * 2;
+
return 0;
init_fail: