From 55746d28d66860bccaae20a67b55b9d5db7c14af Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 22 Nov 2017 12:57:09 +0100 Subject: [PATCH] HID: multitouch: Only look at non touch fields in first packet of a frame 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 Reviewed-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/hid-multitouch.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index d8b1cad74faf..760c4a042e6a 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -787,9 +787,11 @@ 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; @@ -846,6 +848,15 @@ 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); @@ -866,6 +877,7 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report) struct mt_device *td = hid_get_drvdata(hid); __s32 cls = td->mtclass.name; struct hid_field *field; + bool first_packet; unsigned count; int r, n, scantime = 0; @@ -901,6 +913,7 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report) } td->prev_scantime = scantime; + first_packet = td->num_received == 0; for (r = 0; r < report->maxfield; r++) { field = report->field[r]; count = field->report_count; @@ -910,7 +923,7 @@ 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)