lkml.org 
[lkml]   [2010]   [May]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[019/117] sfc: Wait at most 10ms for the MC to finish reading out MAC statistics
    2.6.33-stable review patch.  If anyone has any objections, please let us know.

    ------------------

    From: Ben Hutchings <bhutchings@solarflare.com>

    commit aabc5649078310094cbffb430fcbf9c25b6268f9 upstream.

    The original code would wait indefinitely if MAC stats DMA failed.

    Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    drivers/net/sfc/siena.c | 13 +++++++++++--
    1 file changed, 11 insertions(+), 2 deletions(-)

    --- a/drivers/net/sfc/siena.c
    +++ b/drivers/net/sfc/siena.c
    @@ -454,8 +454,17 @@ static int siena_try_update_nic_stats(st

    static void siena_update_nic_stats(struct efx_nic *efx)
    {
    - while (siena_try_update_nic_stats(efx) == -EAGAIN)
    - cpu_relax();
    + int retry;
    +
    + /* If we're unlucky enough to read statistics wduring the DMA, wait
    + * up to 10ms for it to finish (typically takes <500us) */
    + for (retry = 0; retry < 100; ++retry) {
    + if (siena_try_update_nic_stats(efx) == 0)
    + return;
    + udelay(100);
    + }
    +
    + /* Use the old values instead */
    }

    static void siena_start_nic_stats(struct efx_nic *efx)



    \
     
     \ /
      Last update: 2010-05-12 10:17    [W:0.020 / U:96.152 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site