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Commit 86e88f0e authored by Jason Gerecke's avatar Jason Gerecke Committed by Jiri Kosina
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HID: wacom: Call 'wacom_query_tablet_data' only after 'hid_hw_start'



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 3b164a00 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: default avatarJason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: default avatarPing Cheng <pingc@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 8253d42b
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