[PATCH] Fix ALPS touchpad detection

[Akio Idehara]

ALPS touchpad detection fails if some buttons of ALPS are pressed.
The reason is that the query response byte is different from what is expected.
This was tested on a Toshiba Portege R500.

Signed-off-by: Akio Idehara <zbe64533@xxxxxxxxx>
---
 Documentation/input/alps.txt |    3 ++-
 drivers/input/mouse/alps.c   |    5 +++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/Documentation/input/alps.txt b/Documentation/input/alps.txt
index f274c28..2f95308 100644
--- a/Documentation/input/alps.txt
+++ b/Documentation/input/alps.txt
@@ -13,7 +13,8 @@ Detection

 All ALPS touchpads should respond to the "E6 report" command sequence:
 E8-E6-E6-E6-E9. An ALPS touchpad should respond with either 00-00-0A or
-00-00-64.
+00-00-64 if no buttons are pressed. The bits 0-2 of the first byte will be 1s
+if some buttons are pressed.

 If the E6 report is successful, the touchpad model is identified using the "E7
 report" sequence: E8-E7-E7-E7-E9. The response is the model signature and is
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index bd87380..d161831 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -952,7 +952,8 @@ static const struct alps_model_info *alps_get_model(struct psmouse *psmouse, int

 	/*
 	 * First try "E6 report".
-	 * ALPS should return 0,0,10 or 0,0,100
+	 * ALPS should return 0,0,10 or 0,0,100 if no buttons are pressed.
+	 * The bits 0-2 of the first byte will be 1s if some buttons are pressed.
 	 */
 	param[0] = 0;
 	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
@@ -968,7 +969,7 @@ static const struct alps_model_info *alps_get_model(struct psmouse *psmouse, int
 	psmouse_dbg(psmouse, "E6 report: %2.2x %2.2x %2.2x",
 		    param[0], param[1], param[2]);

-	if (param[0] != 0 || param[1] != 0 || (param[2] != 10 && param[2] != 100))
+	if ((param[0] & 0xf8) != 0 || param[1] != 0 || (param[2] != 10 && param[2] != 100))
 		return NULL;

 	/*
--
1.7.9
--
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