HID: wacom: fix Bamboo ONE oops

Looks like recent changes in the Wacom driver made the Bamboo ONE crashes.
The tablet behaves as if it was a regular Bamboo device with pen, touch
and pad, but there is no physical pad connected to it.
The weird part is that the pad is still sending events and given that
there is no input node connected to it, we get  anull pointer exception.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1317116
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index bd198bbd4df0841b5a3596c09ecac822ecda40e5..02c4efea241c02eb6270d19b40cc90256b04721a 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2425,6 +2425,17 @@ void wacom_setup_device_quirks(struct wacom *wacom)
                }
        }
 
+       /*
+        * Hack for the Bamboo One:
+        * the device presents a PAD/Touch interface as most Bamboos and even
+        * sends ghosts PAD data on it. However, later, we must disable this
+        * ghost interface, and we can not detect it unless we set it here
+        * to WACOM_DEVICETYPE_PAD or WACOM_DEVICETYPE_TOUCH.
+        */
+       if (features->type == BAMBOO_PEN &&
+           features->pktlen == WACOM_PKGLEN_BBTOUCH3)
+               features->device_type |= WACOM_DEVICETYPE_PAD;
+
        /*
         * Raw Wacom-mode pen and touch events both come from interface
         * 0, whose HID descriptor has an application usage of 0xFF0D