On Tue, 3 Nov 2015, Jason Gerecke wrote: > When connecting the Cintiq Companion 2 as an external tablet (i.e., using > it in "hybrid" mode) it has been seen to cause the kernel of the machine > it is connected to to Oops. The cause has been traced to us attempting to > switch the tablet's mode prior to actually starting HID device (resulting > in the eventual dereference of the uninitialized control URB). > > Commit 3b164a0 moved the mode switch from occuring post-start to occurring > pre-start. The change was not seen to cause issues largely due to the fact > that most devices mode switch with 'hid_hw_raw_request' (which is safe to > call prior to start) rather than 'hid_hw_request'. > > Moving the call back to its original location resolves the issue, but > causes some touch-only Bamboo tablets (e.g. 056a:00d0) to stop working. > The affected tablets require us to perform a mode switch on their > vestigial pen interface prior ignoring with -ENODEV, meaning that the > code which is responsible for doing the ignoring has to move as well. > > Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx> > --- > Jiri, > > Ping clued me in to the fact that 'wacom_query_tablet_data' hasn't always > been in this problematic location. The offending commit mentioned in the > revised commit summary is queued for 4.4, so this only needs to get into > the next RC rather than be targeted for stable. Queued as super-late patch into for-4.4/wacom. -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
