Locking sequence of iw_cxgb4 and RoCE drivers in ib_register_device() is
slightly different and this leads to possible circular dependency locking
warning when both the devices are brought up.
Here is the locking sequence upto ib_register_device():
iw_cxgb4: rtnl_mutex(net stack) --> uld_mutex --> device_mutex
RoCE drivers: device_mutex --> rtnl_mutex
Here is the possibility of cross locking:
CPU #0 (iw_cxgb4) CPU #1 (RoCE drivers)
-> on interface up cxgb4_up()
executed with rtnl_mutex held
-> hold uld_mutex and try
registering ib device
-> In ib_register_device() hold
device_mutex
-> hold device mutex in
ib_register_device
-> try acquiring rtnl_mutex in
ib_enum_roce_netdev()
Current patch schedules the ib_register_device() functionality of
iw_cxgb4 to a workqueue to prevent the possible cross-locking.
Also rename the labels in c4iw_reister_device().
Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
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