[SRU][Xenial][Yakkety][PATCH] HID: alps: fix multitouch cursor issue

Phidias Chiang phidias.chiang at canonical.com
Tue Nov 15 09:28:55 UTC 2016


From: Masaki Ota <012nexus at gmail.com>

BugLink: http://bugs.launchpad.net/bugs/1641874

Issue reproduction procedure:

1. three or more fingers put on Touchpad.
2. release fingers from Touchpad.
3. move the cursor by one finger.
4. the cursor does not move.

Cause:

We do not notify multi fingers state correctly to input subsystem.  For
example, when three fingers release from Touchpad, fingers state is 3 -> 0. It
needs to notify first, second and third finger's releasing state.

Fix this by not breaking out on z axis and move x,y,z input handling
code to the correct place so that it's in fact per-finger.

[jkosina at suse.cz: reword changelog]
Signed-off-by: Masaki Ota <masaki.ota at jp.alps.com>
Signed-off-by: Jiri Kosina <jkosina at suse.cz>

(cherry picked from commit 9a54cf462d6f3c383a5a4f5fe15c020a03db44e6)
Signed-off-by: Phidias Chiang <phidias.chiang at canonical.com>
---
 drivers/hid/hid-alps.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/hid/hid-alps.c b/drivers/hid/hid-alps.c
index 390f8d3..82aeca4 100644
--- a/drivers/hid/hid-alps.c
+++ b/drivers/hid/hid-alps.c
@@ -190,16 +190,16 @@ static int alps_raw_event(struct hid_device *hdev,
 			if (z != 0) {
 				input_mt_report_slot_state(hdata->input,
 					MT_TOOL_FINGER, 1);
+				input_report_abs(hdata->input,
+					ABS_MT_POSITION_X, x);
+				input_report_abs(hdata->input,
+					ABS_MT_POSITION_Y, y);
+				input_report_abs(hdata->input,
+					ABS_MT_PRESSURE, z);
 			} else {
 				input_mt_report_slot_state(hdata->input,
 					MT_TOOL_FINGER, 0);
-				break;
 			}
-
-			input_report_abs(hdata->input, ABS_MT_POSITION_X, x);
-			input_report_abs(hdata->input, ABS_MT_POSITION_Y, y);
-			input_report_abs(hdata->input, ABS_MT_PRESSURE, z);
-
 		}
 
 		input_mt_sync_frame(hdata->input);
-- 
2.7.3





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