• Dmitri Epshtein's avatar
    net: mvneta: set real interrupt per packet for tx_done · 06708f81
    Dmitri Epshtein authored
    Commit aebea2ba ("net: mvneta: fix Tx interrupt delay") intended to
    set coalescing threshold to a value guaranteeing interrupt generation
    per each sent packet, so that buffers can be released with no delay.
    
    In fact setting threshold to '1' was wrong, because it causes interrupt
    every two packets. According to the documentation a reason behind it is
    following - interrupt occurs once sent buffers counter reaches a value,
    which is higher than one specified in MVNETA_TXQ_SIZE_REG(q). This
    behavior was confirmed during tests. Also when testing the SoC working
    as a NAS device, better performance was observed with int-per-packet,
    as it strongly depends on the fact that all transmitted packets are
    released immediately.
    
    This commit enables NETA controller work in interrupt per sent packet mode
    by setting coalescing threshold to 0.
    Signed-off-by: default avatarDmitri Epshtein <dima@marvell.com>
    Signed-off-by: default avatarMarcin Wojtas <mw@semihalf.com>
    Cc: <stable@vger.kernel.org> # v3.10+
    Fixes aebea2ba ("net: mvneta: fix Tx interrupt delay")
    Acked-by: default avatarWilly Tarreau <w@1wt.eu>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    06708f81
mvneta.c 114 KB