Patch "Input: ALPS - fix TrackStick support for SS5 hardware" has been added to the 4.9-stable tree

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

Input: ALPS - fix TrackStick support for SS5 hardware

to the 4.9-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-trackstick-support-for-ss5-hardware.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Paul Donohue <[email protected]>
Date: Mon, 28 Nov 2016 20:11:25 -0800
Subject: Input: ALPS - fix TrackStick support for SS5 hardware
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From: Paul Donohue <[email protected]>

commit 864db9295b06837d11a260e5dacf99a3fdf6bce2 upstream.

The current Alps SS5 (SS4 v2) code generates bogus TouchPad events when TrackStick packets are processed.

This causes the xorg synaptics driver to print
"unable to find touch point 0" and
"BUG: triggered 'if (priv->num_active_touches > priv->num_slots)'" messages. It also causes unexpected TouchPad button release and re-click event sequences if the TrackStick is moved while holding a TouchPad button.

This commit corrects the problem by adjusting alps_process_packet_ss4_v2() so that it only sends TrackStick reports when processing TrackStick packets.

---
 drivers/input/mouse/alps.c |   19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

@@ -1346,6 +1346,18 @@ static void alps_process_packet_ss4_v2(s
 
 	priv->multi_packet = 0;
 
+	/* Report trackstick */
+	if (alps_get_pkt_id_ss4_v2(packet) == SS4_PACKET_ID_STICK) {
+		if (priv->flags & ALPS_DUALPOINT) {
+			input_report_key(dev2, BTN_LEFT, f->ts_left);
+			input_report_key(dev2, BTN_RIGHT, f->ts_right);
+			input_report_key(dev2, BTN_MIDDLE, f->ts_middle);
+			input_sync(dev2);
+		}
+		return;
+	}
+
+	/* Report touchpad */
 	alps_report_mt_data(psmouse, (f->fingers <= 4) ? f->fingers : 4);
 
 	input_mt_report_finger_count(dev, f->fingers);

@@ -1356,13 +1368,6 @@ static void alps_process_packet_ss4_v2(s
 
 	input_report_abs(dev, ABS_PRESSURE, f->pressure);
 	input_sync(dev);
-
-	if (priv->flags & ALPS_DUALPOINT) {
-		input_report_key(dev2, BTN_LEFT, f->ts_left);
-		input_report_key(dev2, BTN_RIGHT, f->ts_right);
-		input_report_key(dev2, BTN_MIDDLE, f->ts_middle);
-		input_sync(dev2);
-	}
 }
 
 static bool alps_is_valid_package_ss4_v2(struct psmouse *psmouse)

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/input-alps-fix-trackstick-support-for-ss5-hardware.patch