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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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.