Patch "Input: alps - fix touchpad buttons getting stuck when used with trackpoint" has been added to the 4.0-stable tree

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

Input: alps - fix touchpad buttons getting stuck when used with trackpoint

to the 4.0-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-touchpad-buttons-getting-stuck-when-used-with-trackpoint.patch
and it can be found in the queue-4.0 subdirectory.

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

From: Hans de Goede <[email protected]>
Date: Wed, 8 Apr 2015 09:26:42 -0700
Subject: Input: alps - fix touchpad buttons getting stuck when used with trackpoint
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From: Hans de Goede <[email protected]>

commit 6bcca19f5dcedc3a006ca0bcc3699a437cadee74 upstream.

When the left touchpad button gets pressed, and then the trackpoint is moved, and then the button is released, the following happens:

1) touchpad packet is received, touchpad evdev node reports BTN_LEFT 1

2) pointing stick packet is received, the hw will report a BTN_LEFT 1 in this packet because when the trackstick is active it communicates the combined touchpad + pointing stick buttons in the trackstick packet, since alps_report_bare_ps2_packet passes NULL (*) for the dev2 parameter to alps_report_buttons the combining is not detected and the pointing stick evdev node will also report BTN_LEFT 1

3) on release of the button a pointing stick packet with BTN_LEFT 0 is received and the pointing stick evdev node will report BTN_LEFT 0

Note how because of the passing as NULL for dev2 the touchpad evdev node will never send BTN_LEFT 0 in this scenario leading to a stuck mouse button.

This is a regression in 4.0 introduced by commit 04aae283ba6a8 ("Input: ALPS - do not mix trackstick and external PS/2 mouse data")

This commit fixes this by passing in the touchpad evdev as dev2 parameter when calling alps_report_buttons for the pointingstick on alps v2 devices, so that alps_report_buttons correctly detect that we're already reporting the button as pressed via the touchpad evdev node, and will also send the release event there.

---
 drivers/input/mouse/alps.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -1159,13 +1159,14 @@ static void alps_report_bare_ps2_packet(
 					bool report_buttons)
 {
 	struct alps_data *priv = psmouse->private;
-	struct input_dev *dev;
+	struct input_dev *dev, *dev2 = NULL;
 
 	/* Figure out which device to use to report the bare packet */
 	if (priv->proto_version == ALPS_PROTO_V2 &&
 	    (priv->flags & ALPS_DUALPOINT)) {
 		/* On V2 devices the DualPoint Stick reports bare packets */
 		dev = priv->dev2;
+		dev2 = psmouse->dev;
 	} else if (unlikely(IS_ERR_OR_NULL(priv->dev3))) {
 		/* Register dev3 mouse if we received PS/2 packet first time */
 		if (!IS_ERR(priv->dev3))

@@ -1177,7 +1178,7 @@ static void alps_report_bare_ps2_packet(
 	}
 
 	if (report_buttons)
-		alps_report_buttons(dev, NULL,
+		alps_report_buttons(dev, dev2,
 				packet[0] & 1, packet[0] & 2, packet[0] & 4);
 
 	input_report_rel(dev, REL_X,

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

queue-4.0/input-alps-fix-touchpad-buttons-getting-stuck-when-used-with-trackpoint.patch