tree 21d3819588970ea7e0421d79df088332fcadbb17
parent 6eff208f479d6fe99fd92c0e6bf7e930bb45cd30
author Cornelia Huck <cornelia.huck@de.ibm.com> 1230208748 +0100
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1230208748 +0100

[S390] cio: Only register ccw_device for registered subchannel.

There is a race between io_subchannel_register() and
io_subchannel_sch_event() which may cause a subchannel to be
unregistered because it is no longer operational before
io_subchannel_register() had run. We need to check whether the
subchannel is still registered before the ccw device can be
registered and just bail out if it is not.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>