Fix left-button not working with some hid-multitouch touchpads

1 files changed, 84 insertions, 0 deletions

diff --git a/0002-HID-multitouch-Only-look-at-non-touch-fields-in-firs.patch b/0002-HID-multitouch-Only-look-at-non-touch-fields-in-firs.patch
new file mode 100644
index 000000000..3ea374ff5
--- /dev/null
+++ b/0002-HID-multitouch-Only-look-at-non-touch-fields-in-firs.patch
@@ -0,0 +1,84 @@
+From c25d877f4ee97deb92170129eee4777a5d5997d9 Mon Sep 17 00:00:00 2001
+From: Hans de Goede <hdegoede@redhat.com>
+Date: Wed, 22 Nov 2017 12:57:09 +0100
+Subject: [PATCH v2 2/3] 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 <hdegoede@redhat.com>
+Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
+Signed-off-by: Jiri Kosina <jkosina@suse.cz>
+---
+ 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)
+-- 
+2.14.3
+