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Commit 76d7cc03 authored by Roland Dreier's avatar Roland Dreier
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IB/mthca: Use mmiowb() to avoid firmware commands getting jumbled up



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>
parent dcb3f974
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