• Roland Dreier's avatar
    IB/mthca: Use mmiowb() to avoid firmware commands getting jumbled up · 76d7cc03
    Roland Dreier authored
    Firmware commands are sent to the HCA by writing multiple words to a
    command register block.  Access to this block of registers is
    serialized with a mutex.  However, on large SGI systems, problems were
    seen with multiple CPUs issuing FW commands at the same time, because
    the writes to the register block may be reordered within the system
    interconnect and reach the HCA in a different order than they were
    issued (even with the mutex).  Fix this by adding an mmiowb() before
    dropping the mutex.
    Tested-by: default avatarArthur Kepner <akepner@sgi.com>
    Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
    76d7cc03
mthca_cmd.c 56.9 KB