[Xenial][SRU][PATCH 1/2] Revert "HID: multitouch: enable palm rejection if device implements confidence usage"

[Phidias Chiang]

From: Allen Hung <allen_hung at dell.com>

BugLink: http://bugs.launchpad.net/bugs/1593124

This reverts commit 25a84db15b3f ("HID: multitouch: enable palm rejection
if device implements confidence usage")

The commit enables palm rejection for Win8 Precision Touchpad devices but
the quirk MT_QUIRK_VALID_IS_CONFIDENCE it is using is not working very
properly. This quirk is originally designed for some WIn7 touchscreens. Use
of this for a Win8 Precision Touchpad will cause unexpected pointer jumping
problem.

Cc: stable at vger.kernel.org # v4.5+
Reviewed-by: Benjamin Tissoires <benjamin.tissoires at redhat.com>
Tested-by: Andy Lutomirski <luto at kernel.org> # XPS 13 9350, BIOS 1.4.3
Signed-off-by: Allen Hung <allen_hung at dell.com>
Signed-off-by: Jiri Kosina <jkosina at suse.cz>
(cherry picked from commit 62630ea768869beeb1e514b0bf5607a0c9b93d12)
Signed-off-by: Phidias Chiang <phidias.chiang at canonical.com>
---
 drivers/hid/hid-multitouch.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index ecf2e85..c5ec4f9 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -502,11 +502,6 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			mt_store_field(usage, td, hi);
 			return 1;
 		case HID_DG_CONFIDENCE:
-			if (cls->name == MT_CLS_WIN_8 &&
-				field->application == HID_DG_TOUCHPAD) {
-				cls->quirks &= ~MT_QUIRK_ALWAYS_VALID;
-				cls->quirks |= MT_QUIRK_VALID_IS_CONFIDENCE;
-			}
 			mt_store_field(usage, td, hi);
 			return 1;
 		case HID_DG_TIPSWITCH:
-- 
2.7.3