Patch "Input: ALPS - fix two-finger scroll breakage in right side on ALPS touchpad" has been added to the 4.12-stable tree

gregkh
2017-08-27T07:48:20Z

This is a note to let you know that I've just added the patch titled

Input: ALPS - fix two-finger scroll breakage in right side on ALPS touchpad

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
input-alps-fix-two-finger-scroll-breakage-in-right-side-on-alps-touchpad.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.

>From 4a646580f793d19717f7e034c8d473b509c27d49 Mon Sep 17 00:00:00 2001
From: Masaki Ota <masaki.ota@jp.alps.com>
Date: Thu, 24 Aug 2017 15:44:36 -0700
Subject: Input: ALPS - fix two-finger scroll breakage in right side on ALPS touchpad

From: Masaki Ota <masaki.ota@jp.alps.com>

commit 4a646580f793d19717f7e034c8d473b509c27d49 upstream.

Fixed the issue that two finger scroll does not work correctly
on V8 protocol. The cause is that V8 protocol X-coordinate decode
is wrong at SS4 PLUS device. I added SS4 PLUS X decode definition.

Mote notes:
the problem manifests itself by the commit e7348396c6d5 ("Input: ALPS
- fix V8+ protocol handling (73 03 28)"), where a fix for the V8+
protocol was applied. Although the culprit must have been present
beforehand, the two-finger scroll worked casually even with the
wrongly reported values by some reason. It got broken by the commit
above just because it changed x_max value, and this made libinput
correctly figuring the MT events. Since the X coord is reported as
falsely doubled, the events on the right-half side go outside the
boundary, thus they are no longer handled. This resulted as a broken
two-finger scroll.

One finger event is decoded differently, and it didn't suffer from
this problem. The problem was only about MT events. --tiwai

Fixes: e7348396c6d5 ("Input: ALPS - fix V8+ protocol handling (73 03 28)")
Signed-off-by: Masaki Ota <masaki.ota@jp.alps.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Paul Donohue <linux-kernel@PaulSD.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/input/mouse/alps.c | 41 +++++++++++++++++++++++++++++++----------
drivers/input/mouse/alps.h | 8 ++++++++
2 files changed, 39 insertions(+), 10 deletions(-)

--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -1215,14 +1215,24 @@ static int alps_decode_ss4_v2(struct alp

case SS4_PACKET_ID_TWO:
if (priv->flags & ALPS_BUTTONPAD) {
- f->mt[0].x = SS4_BTL_MF_X_V2(p, 0);
+ if (IS_SS4PLUS_DEV(priv->dev_id)) {
+ f->mt[0].x = SS4_PLUS_BTL_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_PLUS_BTL_MF_X_V2(p, 1);
+ } else {
+ f->mt[0].x = SS4_BTL_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_BTL_MF_X_V2(p, 1);
+ }
f->mt[0].y = SS4_BTL_MF_Y_V2(p, 0);
- f->mt[1].x = SS4_BTL_MF_X_V2(p, 1);
f->mt[1].y = SS4_BTL_MF_Y_V2(p, 1);
} else {
- f->mt[0].x = SS4_STD_MF_X_V2(p, 0);
+ if (IS_SS4PLUS_DEV(priv->dev_id)) {
+ f->mt[0].x = SS4_PLUS_STD_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_PLUS_STD_MF_X_V2(p, 1);
+ } else {
+ f->mt[0].x = SS4_STD_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_STD_MF_X_V2(p, 1);
+ }
f->mt[0].y = SS4_STD_MF_Y_V2(p, 0);
- f->mt[1].x = SS4_STD_MF_X_V2(p, 1);
f->mt[1].y = SS4_STD_MF_Y_V2(p, 1);
}
f->pressure = SS4_MF_Z_V2(p, 0) ? 0x30 : 0;
@@ -1239,16 +1249,27 @@ static int alps_decode_ss4_v2(struct alp

case SS4_PACKET_ID_MULTI:
if (priv->flags & ALPS_BUTTONPAD) {
- f->mt[2].x = SS4_BTL_MF_X_V2(p, 0);
+ if (IS_SS4PLUS_DEV(priv->dev_id)) {
+ f->mt[0].x = SS4_PLUS_BTL_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_PLUS_BTL_MF_X_V2(p, 1);
+ } else {
+ f->mt[2].x = SS4_BTL_MF_X_V2(p, 0);
+ f->mt[3].x = SS4_BTL_MF_X_V2(p, 1);
+ }
+
f->mt[2].y = SS4_BTL_MF_Y_V2(p, 0);
- f->mt[3].x = SS4_BTL_MF_X_V2(p, 1);
f->mt[3].y = SS4_BTL_MF_Y_V2(p, 1);
no_data_x = SS4_MFPACKET_NO_AX_BL;
no_data_y = SS4_MFPACKET_NO_AY_BL;
} else {
- f->mt[2].x = SS4_STD_MF_X_V2(p, 0);
+ if (IS_SS4PLUS_DEV(priv->dev_id)) {
+ f->mt[0].x = SS4_PLUS_STD_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_PLUS_STD_MF_X_V2(p, 1);
+ } else {
+ f->mt[0].x = SS4_STD_MF_X_V2(p, 0);
+ f->mt[1].x = SS4_STD_MF_X_V2(p, 1);
+ }
f->mt[2].y = SS4_STD_MF_Y_V2(p, 0);
- f->mt[3].x = SS4_STD_MF_X_V2(p, 1);
f->mt[3].y = SS4_STD_MF_Y_V2(p, 1);
no_data_x = SS4_MFPACKET_NO_AX;
no_data_y = SS4_MFPACKET_NO_AY;
@@ -2541,8 +2562,8 @@ static int alps_set_defaults_ss4_v2(stru

memset(otp, 0, sizeof(otp));

- if (alps_get_otp_values_ss4_v2(psmouse, 0, &otp[0][0]) ||
- alps_get_otp_values_ss4_v2(psmouse, 1, &otp[1][0]))
+ if (alps_get_otp_values_ss4_v2(psmouse, 1, &otp[1][0]) ||
+ alps_get_otp_values_ss4_v2(psmouse, 0, &otp[0][0]))
return -1;

alps_update_device_area_ss4_v2(otp, priv);
--- a/drivers/input/mouse/alps.h
+++ b/drivers/input/mouse/alps.h
@@ -100,6 +100,10 @@ enum SS4_PACKET_ID {
((_b[1 + _i * 3] << 5) & 0x1F00) \
)

+#define SS4_PLUS_STD_MF_X_V2(_b, _i) (((_b[0 + (_i) * 3] << 4) & 0x0070) | \
+ ((_b[1 + (_i) * 3] << 4) & 0x0F80) \
+ )
+
#define SS4_STD_MF_Y_V2(_b, _i) (((_b[1 + (_i) * 3] << 3) & 0x0010) | \
((_b[2 + (_i) * 3] << 5) & 0x01E0) | \
((_b[2 + (_i) * 3] << 4) & 0x0E00) \
@@ -109,6 +113,10 @@ enum SS4_PACKET_ID {
((_b[0 + (_i) * 3] >> 3) & 0x0010) \
)

+#define SS4_PLUS_BTL_MF_X_V2(_b, _i) (SS4_PLUS_STD_MF_X_V2(_b, _i) | \
+ ((_b[0 + (_i) * 3] >> 4) & 0x0008) \
+ )
+
#define SS4_BTL_MF_Y_V2(_b, _i) (SS4_STD_MF_Y_V2(_b, _i) | \
((_b[0 + (_i) * 3] >> 3) & 0x0008) \
)

Patches currently in stable-queue which might be from masaki.ota@jp.alps.com are

queue-4.12/input-alps-fix-two-finger-scroll-breakage-in-right-side-on-alps-touchpad.patch