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

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.

Reported-and-tested-by: Douglas Christman <douglaschristman@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/input/alps.txt b/Documentation/input/alps.txt
index e301887d8523674dbc2e544dca4c8deedb86faef..765d99cdadbbe20a192ad2474ed6e2ba50e6ccd7 100644 (file)
--- a/Documentation/input/alps.txt
+++ b/Documentation/input/alps.txt
@@ -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
 ---------------------------------------------

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 113d6f1516a54956f74635f7eb51231ab5490052..4d246861d692b810f3074aa7917cda86893ac6c2 100644 (file)
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -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 alps_v6_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(struct psmouse *psmouse)
                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;
@@ -2550,6 +2552,8 @@ static int alps_set_protocol(struct psmouse *psmouse,
        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;