I saw this on ARM:
linux/drivers/xen/dbgp.c:11:23: warning: unused variable 'ctrlr' [-Wunused-variable]
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Acked-by: NJan Beulich <JBeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Just like for the in-tree early console debug port driver, the
hypervisor - when using a debug port based console - also needs to be
told about controller resets, so it can suppress using and then
re-initialize the debug port accordingly.

Other than the in-tree driver, the hypervisor driver actually cares
about doing this only for the device where the debug is port actually
in use, i.e. it needs to be told the coordinates of the device being
reset (quite obviously, leveraging the addition done for that would
likely benefit the in-tree driver too).
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>