On Sunday 09 November 2014 09:05:04 Dmitry Torokhov wrote:

Hi Pali,

On Sun, Nov 02, 2014 at 12:25:10AM +0100, Pali Rohár wrote:

quoted

 int alps_detect(struct psmouse *psmouse, bool
 set_properties) {

-	struct alps_data dummy;
+	unsigned char e6[4];

-	if (alps_identify(psmouse, &dummy) < 0)
-		return -1;
+	/*
+	 * Try "E6 report".
+	 * 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.
+	 */
+	if (alps_rpt_cmd(psmouse, PSMOUSE_CMD_SETRES,
+			 PSMOUSE_CMD_SETSCALE11, e6))
+		return -EIO;
+
+	if ((e6[0] & 0xf8) != 0 || e6[1] != 0 || (e6[2] != 10 &&
e6[2] != 100)) +		return -EINVAL;

 	if (set_properties) {

+		/*
+		 * NOTE: To detect model and trackstick presence we 

need

quoted

to do +		 *       full device reset. To speed up 

detection

quoted

and prevent +		 *       calling duplicate initialization
sequence (both in +		 *       alps_detect() and
alps_init()) we set model/protocol +		 *       version and
correct name in alps_init() (which will +		 *       do 

full

quoted

device reset). For now set name to DualPoint. +		 */

 		psmouse->vendor = "ALPS";

-		psmouse->name = dummy.flags & ALPS_DUALPOINT ?
-				"DualPoint TouchPad" : "GlidePoint";
-		psmouse->model = dummy.proto_version << 8;
+		psmouse->name = "DualPoint TouchPad";

 	}

+

 	return 0;

We can't do this; going by e6 only will give us false
positives and alps_detect is supposed to be authoritative.

Thanks.

psmouse-base.c is calling alps_detect() and alps_init() 
consecutively so it does not matter if code is in _detect or 
_init function. Just need to make sure that correct order will be 
used. So this patch could not bring any problems.

If psmouse-base.c detect device false-positive as ALPS (with 
alps_detect()) then it immediately calls alps_init() which fails 
and psmouse-base.c will try to use another protocol.

-- 
Pali Rohár
pali.rohar@gmail.com