Patch "Input: alps - only Dell laptops have separate button bits for v2 dualpoint sticks" has been added to the 4.1-stable tree

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

Input: alps - only Dell laptops have separate button bits for v2 dualpoint sticks

to the 4.1-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-only-dell-laptops-have-separate-button-bits-for-v2-dualpoint-sticks.patch
and it can be found in the queue-4.1 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: Mon, 3 Aug 2015 14:06:24 -0700
Subject: Input: alps - only Dell laptops have separate button bits for v2 dualpoint sticks

From: Hans de Goede <[email protected]>

commit 073e570d7c2caae9910a993d56f340be4548a4a8 upstream.

It turns out that only Dell laptops have the separate button bits for v2 dualpoint sticks and that commit 92bac83dd79e ("Input: alps - non interleaved V2 dualpoint has separate stick button bits") causes regressions on Toshiba laptops.

This commit adds a check for Dell laptops to the code for handling these extra button bits, fixing this regression.

This patch has been tested on a Dell Latitude D620 to make sure that it does not reintroduce the original problem.

---
 Documentation/input/alps.txt |    6 ++++--
 drivers/input/mouse/alps.c   |    8 ++++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

@@ -119,8 +119,10 @@ ALPS Absolute Mode - Protocol Version 2
  byte 5:  0   z6   z5   z4   z3   z2   z1   z0
 
 Protocol Version 2 DualPoint devices send standard PS/2 mouse packets for
-the DualPoint Stick. For non interleaved dualpoint devices the pointingstick
-buttons get reported separately in the PSM, PSR and PSL bits.
+the DualPoint Stick. The M, R and L bits signal the combined status of both
+the pointingstick and touchpad buttons, except for Dell dualpoint devices
+where the pointingstick buttons get reported separately in the PSM, PSR
+and PSL bits.
 
 Dualpoint device -- interleaved packet format
 ---------------------------------------------

@@ -20,6 +20,7 @@
 #include <linux/input/mt.h>
 #include <linux/serio.h>
 #include <linux/libps2.h>
+#include <linux/dmi.h>
 
 #include "psmouse.h"
 #include "alps.h"

@@ -99,6 +100,7 @@ static const struct alps_nibble_commands
 #define ALPS_FOUR_BUTTONS	0x40	/* 4 direction button present */
 #define ALPS_PS2_INTERLEAVED	0x80	/* 3-byte PS/2 packet interleaved with
 					   6-byte ALPS packet */
+#define ALPS_DELL		0x100	/* device is a Dell laptop */
 #define ALPS_BUTTONPAD		0x200	/* device is a clickpad */
 
 static const struct alps_model_info alps_model_data[] = {

@@ -251,9 +253,9 @@ static void alps_process_packet_v1_v2(st
 		return;
 	}
 
-	/* Non interleaved V2 dualpoint has separate stick button bits */
+	/* Dell non interleaved V2 dualpoint has separate stick button bits */
 	if (priv->proto_version == ALPS_PROTO_V2 &&
-	    priv->flags == (ALPS_PASS | ALPS_DUALPOINT)) {
+	    priv->flags == (ALPS_DELL | ALPS_PASS | ALPS_DUALPOINT)) {
 		left |= packet[0] & 1;
 		right |= packet[0] & 2;
 		middle |= packet[0] & 4;

@@ -2542,6 +2544,8 @@ static int alps_set_protocol(struct psmo
 	priv->byte0 = protocol->byte0;
 	priv->mask0 = protocol->mask0;
 	priv->flags = protocol->flags;
+	if (dmi_name_in_vendors("Dell"))
+		priv->flags |= ALPS_DELL;
 
 	priv->x_max = 2000;
 	priv->y_max = 1400;

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

queue-4.1/input-alps-only-dell-laptops-have-separate-button-bits-for-v2-dualpoint-sticks.patch