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  • Jeff Roberson's avatar
    edac: i5400 fix csrow mapping · 156edd4a
    Jeff Roberson authored
    
    
    The i5400 EDAC driver has several bugs with chip-select row computation
    which most likely lead to bugs in detailed error reporting.  Attempts to
    contact the authors have gone mostly unanswered so I am presenting my diff
    here.  I do not subscribe to lkml and would appreciate being kept in the
    cc.
    
    The most egregious problem was miscalculating the addresses of MTR
    registers after register 0 by assuming they are 32bit rather than 16.
    This caused the driver to miss half of the memories.  Most motherboards
    tend to have only 8 dimm slots and not 16, so this may not have been
    noticed before.
    
    Further, the row calculations multiplied the number of dimms several
    times, ultimately ending up with a maximum row of 32.  The chipset only
    supports 4 dimms in each of 4 channels, so csrow could not be higher than
    4 unless you use a row per-rank with dual-rank dimms.  I opted to
    eliminate this behavior as it is confusing to the user and the error
    reporting works by slot and not rank.  This gives a much clearer view of
    memory by slot and channel in /sys.
    
    Signed-off-by: default avatarJeff Roberson <jroberson@jroberson.net>
    Signed-off-by: default avatarDoug Thompson <dougthompson@xmission.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    156edd4a