Re: [PATCH 1/1][Resend] Input: cypress_ps2 - Return zero fingercount if palm is detected.

From: Dmitry Torokhov
Date: Wed Oct 16 2013 - 14:35:51 EST


Hi Joe,

On Fri, Oct 11, 2013 at 12:30:43PM -0400, Joseph Salisbury wrote:
> On 09/30/2013 04:12 PM, Kamal Mostafa wrote:
> > On Tue, 2013-09-24 at 11:44 -0400, Joseph Salisbury wrote:
> >> BugLink: http://bugs.launchpad.net/bugs/1229361
> >>
> >> This patch sets the finger count to 0 in the case of palm contact.
> >>
> >> Signed-off-by: Joseph Salisbury <joseph.salisbury@xxxxxxxxxxxxx>
> >> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> (maintainer:INPUT (KEYBOARD,...,commit_signer:2/2=100%)
> >> Cc: Henrik Rydberg <rydberg@xxxxxxxxxxx> (maintainer:INPUT MULTITOUCH...)
> >> Cc: Kamal Mostafa <kamal@xxxxxxxxxxxxx> (commit_signer:2/2=100%)
> >> Cc: Dudley Du <dudl@xxxxxxxxxxx> (commit_signer:2/2=100%)
> >> Cc: Kyle Fazzari <git@xxxxxxxxxxxxxxxxx> (commit_signer:1/2=50%)
> >> Cc: Tim Gardner <tim.gardner@xxxxxxxxxxxxx> (commit_signer:1/2=50%)
> >> Cc: linux-input@xxxxxxxxxxxxxxx (open list:INPUT (KEYBOARD,...)
> >> Cc: linux-kernel@xxxxxxxxxxxxxxx (open list)
> >> Cc: stable@xxxxxxxxxxxxxxx
> > This patch works fine: eliminates stream of junk driver messages with no
> > ill effects.
> >
> > Tested-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
> >
> > -Kamal
> >
> >
> >> ---
> >> drivers/input/mouse/cypress_ps2.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/input/mouse/cypress_ps2.c b/drivers/input/mouse/cypress_ps2.c
> >> index 45b3eda..95b2c40 100644
> >> --- a/drivers/input/mouse/cypress_ps2.c
> >> +++ b/drivers/input/mouse/cypress_ps2.c
> >> @@ -441,7 +441,7 @@ static int cypress_get_finger_count(unsigned char header_byte)
> >> case 2: return 5;
> >> default:
> >> /* Invalid contact (e.g. palm). Ignore it. */
> >> - return -1;
> >> + return 0;
> >> }
> >> }
> >>
> >> @@ -460,7 +460,7 @@ static int cypress_parse_packet(struct psmouse *psmouse,
> >>
> >> contact_cnt = cypress_get_finger_count(header_byte);
> >>
> >> - if (contact_cnt < 0) /* e.g. palm detect */
> >> + if (contact_cnt < 0)
> >> return -EINVAL;
> >>
> >> report_data->contact_cnt = contact_cnt;
> Hi Dmitry and Henrik,
>
> Have you had a chance to review this patch to consider it for inclusion
> in mainline?

I think the main problem is that we were reporting PSMOUSE_BAD_DATA for
palm packets.

Could you try a slightly extended patch below to make sure it all still
works?

Thanks!

--
Dmitry

Input: cypress_ps2 - do not consider data bad if palm is detected

From: Joseph Salisbury <joseph.salisbury@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Tested-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/input/mouse/cypress_ps2.c | 20 +++-----------------
1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/drivers/input/mouse/cypress_ps2.c b/drivers/input/mouse/cypress_ps2.c
index ef651cc..e499e55 100644
--- a/drivers/input/mouse/cypress_ps2.c
+++ b/drivers/input/mouse/cypress_ps2.c
@@ -439,7 +439,7 @@ static int cypress_get_finger_count(unsigned char header_byte)
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 psmouse *psmouse,
{
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(struct psmouse *psmouse, bool zero_pkt)
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;

@@ -604,11 +595,6 @@ static psmouse_ret_t cypress_validate_byte(struct psmouse *psmouse)
if ((packet[0] & 0x08) == 0x08)
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
--
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