• Mark Lord's avatar
    sata_mv: warn on PIO with multiple DRQs · c6112bd8
    Mark Lord authored
    Chip errata sometimes prevents reliable use of PIO commands which involve
    more than a single DRQ (data request).  In normal operation, libata should
    not generate such PIO commands (uses DMA instead), but they could be sent
    in via SG_IO from userspace.
    
    A full workaround might be to break up such commands into sequences
    of single DRQ ones, but that's just way too complex for something
    that doesn't normally happen in real life.
    
    So, allow the attempt (it often works, despite the errata),
    but log the event for reference when somebody screams.
    Signed-off-by: default avatarMark Lord <mlord@pobox.com>
    Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
    c6112bd8
sata_mv.c 95.2 KB