Input: elantech - touchpad driver miss-recognising logitech mice

Some Logitech mice react to the magic knock like Elantech touchpad would.
This leads to those mice being misdetected as Elantech touchpads.  Add a
version query to elantech_detect() to distinguish the two.

[dtor@mail.ru:
 - lower severity of some messages - when we are not sure yet if
   device is Elantech or not not responding to knock is not an error.
]

Signed-off-by: Arjan Opmeer <arjan@opmeer.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index b9a25d5..6ab0eb1 100644 (file)
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -542,7 +542,7 @@ int elantech_detect(struct psmouse *psmouse, int set_properties)
            ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
            ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
            ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
-               pr_err("elantech.c: sending Elantech magic knock failed.\n");
+               pr_debug("elantech.c: sending Elantech magic knock failed.\n");
                return -1;
        }
 
@@ -551,8 +551,27 @@ int elantech_detect(struct psmouse *psmouse, int set_properties)
         * set of magic numbers
         */
        if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
-               pr_info("elantech.c: unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
-                       param[0], param[1], param[2]);
+               pr_debug("elantech.c: "
+                        "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
+                        param[0], param[1], param[2]);
+               return -1;
+       }
+
+       /*
+        * Query touchpad's firmware version and see if it reports known
+        * value to avoid mis-detection. Logitech mice are known to respond
+        * to Elantech magic knock and there might be more.
+        */
+       if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
+               pr_debug("elantech.c: failed to query firmware version.\n");
+               return -1;
+       }
+
+       pr_debug("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
+                param[0], param[1], param[2]);
+
+       if (param[0] == 0 || param[1] != 0) {
+               pr_debug("elantech.c: Probably not a real Elantech touchpad. Aborting.\n");
                return -1;
        }
 
@@ -600,8 +619,7 @@ int elantech_init(struct psmouse *psmouse)
        int i, error;
        unsigned char param[3];
 
-       etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
-       psmouse->private = etd;
+       psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
        if (!etd)
                return -1;
 
@@ -610,14 +628,12 @@ int elantech_init(struct psmouse *psmouse)
                etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
 
        /*
-        * Find out what version hardware this is
+        * Do the version query again so we can store the result
         */
        if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
                pr_err("elantech.c: failed to query firmware version.\n");
                goto init_fail;
        }
-       pr_info("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
-               param[0], param[1], param[2]);
        etd->fw_version_maj = param[0];
        etd->fw_version_min = param[2];