HID: wacom: Don't add ghost interface as shared data

BugLink: http://bugs.launchpad.net/bugs/1681875
commit 8b4073596997f2ccbf68d8e72e07b827388a4536 upstream.

A previous commit (below) adds a check for already probed interfaces to
Wacom's matching heuristic. Unfortunately this causes the Bamboo Pen
(CTL-460) to match itself to its 'ghost' touch interface. After
subsequent changes to the driver this match to the ghost causes the
kernel to crash. This patch avoids calling wacom_add_shared_data()
for the BAMBOO_PEN's ghost touch interface.

Fixes: 41372d5d40e7 ("HID: wacom: Augment 'oVid' and 'oPid' with heuristics for HID_GENERIC")
Signed-off-by: Aaron Armstrong Skomra <aaron.skomra@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 8aeca038cc7331244eeeb5dc0468b22ef66e7d44..5f282bb0ea10c1aab1a105770056f6e39271d426 100644 (file)
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -2081,6 +2081,14 @@ static int wacom_parse_and_register(struct wacom *wacom, bool wireless)
 
        wacom_update_name(wacom, wireless ? " (WL)" : "");
 
+       /* pen only Bamboo neither support touch nor pad */
+       if ((features->type == BAMBOO_PEN) &&
+           ((features->device_type & WACOM_DEVICETYPE_TOUCH) ||
+           (features->device_type & WACOM_DEVICETYPE_PAD))) {
+               error = -ENODEV;
+               goto fail;
+       }
+
        error = wacom_add_shared_data(hdev);
        if (error)
                goto fail;
@@ -2128,14 +2136,6 @@ static int wacom_parse_and_register(struct wacom *wacom, bool wireless)
                goto fail_quirks;
        }
 
-       /* pen only Bamboo neither support touch nor pad */
-       if ((features->type == BAMBOO_PEN) &&
-           ((features->device_type & WACOM_DEVICETYPE_TOUCH) ||
-           (features->device_type & WACOM_DEVICETYPE_PAD))) {
-               error = -ENODEV;
-               goto fail_quirks;
-       }
-
        if (features->device_type & WACOM_DEVICETYPE_WL_MONITOR)
                error = hid_hw_open(hdev);