[PATCH 3.10 120/173] Input: cypress_ps2 - do not consider data bad if palm is detected

Greg Kroah-Hartman
2013-12-02T20:41:37Z

From: Joseph Salisbury <joseph.salisbury@canonical.com>

commit 5df682b297f6b23ec35615ed7bb50cbb25d25869 upstream.

If hardware (or firmware) detects palm on the surface of the device it does
not mean that the data packet is bad from the protocol standpoint. Instead
of reporting PSMOUSE_BAD_DATA in this case simply threat it as if nothing
touches the surface.

BugLink: http://bugs.launchpad.net/bugs/1229361

Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Tested-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/input/mouse/cypress_ps2.c | 19 +++----------------
1 file changed, 3 insertions(+), 16 deletions(-)

--- a/drivers/input/mouse/cypress_ps2.c
+++ b/drivers/input/mouse/cypress_ps2.c
@@ -439,7 +439,7 @@ static int cypress_get_finger_count(unsi
case 2: return 5;
default:
/* Invalid contact (e.g. palm). Ignore it. */
- return -1;
+ return 0;
}
}

@@ -452,17 +452,10 @@ static int cypress_parse_packet(struct p
{
unsigned char *packet = psmouse->packet;
unsigned char header_byte = packet[0];
- int contact_cnt;

memset(report_data, 0, sizeof(struct cytp_report_data));

- contact_cnt = cypress_get_finger_count(header_byte);
-
- if (contact_cnt < 0) /* e.g. palm detect */
- return -EINVAL;
-
- report_data->contact_cnt = contact_cnt;
-
+ report_data->contact_cnt = cypress_get_finger_count(header_byte);
report_data->tap = (header_byte & ABS_MULTIFINGER_TAP) ? 1 : 0;

if (report_data->contact_cnt == 1) {
@@ -535,11 +528,9 @@ static void cypress_process_packet(struc
int slots[CYTP_MAX_MT_SLOTS];
int n;

- if (cypress_parse_packet(psmouse, cytp, &report_data))
- return;
+ cypress_parse_packet(psmouse, cytp, &report_data);

n = report_data.contact_cnt;
-
if (n > CYTP_MAX_MT_SLOTS)
n = CYTP_MAX_MT_SLOTS;

@@ -605,10 +596,6 @@ static psmouse_ret_t cypress_validate_by
return PSMOUSE_BAD_DATA;

contact_cnt = cypress_get_finger_count(packet[0]);
-
- if (contact_cnt < 0)
- return PSMOUSE_BAD_DATA;
-
if (cytp->mode & CYTP_BIT_ABS_NO_PRESSURE)
cypress_set_packet_size(psmouse, contact_cnt == 2 ? 7 : 4);
else