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HID: multitouch: Only look at non touch fields in first packet of a frame

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[ Upstream commit 55746d28d66860bccaae20a67b55b9d5db7c14af ]

Devices in "single finger hybrid mode" will send one report per finger,
on some devices only the first report of such a multi-packet frame will
contain a value for BTN_LEFT, in subsequent reports (if multiple fingers
are down) the value is always 0, causing hid-mt to report BTN_LEFT going
1 - 0 - 1 - 0 when pressing a clickpad and putting down a second finger.
This happens for example on USB 0603:0002 mt touchpads.

This commit fixes this by only reporting non touch fields for the first
packet of a (possibly) multi-packet frame.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hans de Goede 2017-11-22 12:57:09 +01:00 committed by Greg Kroah-Hartman
parent d2bbda4c37
commit addf1ae9fc
1 changed files with 15 additions and 2 deletions
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17
drivers/hid/hid-multitouch.c
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@ -738,9 +738,11 @@ static int mt_touch_event(struct hid_device *hid, struct hid_field *field,
}
static void mt_process_mt_event(struct hid_device *hid, struct hid_field *field,
struct hid_usage *usage, __s32 value)
struct hid_usage *usage, __s32 value,
bool first_packet)
{
struct mt_device *td = hid_get_drvdata(hid);
__s32 cls = td->mtclass.name;
__s32 quirks = td->mtclass.quirks;
struct input_dev *input = field->hidinput->input;
@ -794,6 +796,15 @@ static void mt_process_mt_event(struct hid_device *hid, struct hid_field *field,
break;
default:
/*
* For Win8 PTP touchpads we should only look at
* non finger/touch events in the first_packet of
* a (possible) multi-packet frame.
*/
if ((cls == MT_CLS_WIN_8 || cls == MT_CLS_WIN_8_DUAL) &&
!first_packet)
return;
if (usage->type)
input_event(input, usage->type, usage->code,
value);
@ -813,6 +824,7 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report)
{
struct mt_device *td = hid_get_drvdata(hid);
struct hid_field *field;
bool first_packet;
unsigned count;
int r, n;
@ -831,6 +843,7 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report)
td->num_expected = value;
}
first_packet = td->num_received == 0;
for (r = 0; r < report->maxfield; r++) {
field = report->field[r];
count = field->report_count;
@ -840,7 +853,7 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report)
for (n = 0; n < count; n++)
mt_process_mt_event(hid, field, &field->usage[n],
field->value[n]);
field->value[n], first_packet);
}
if (td->num_received >= td->num_expected)