diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2010-04-28 09:00:35 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-28 12:18:26 -0700 |
| commit | aabc5649078310094cbffb430fcbf9c25b6268f9 (patch) | |
| tree | c633f0c143068b22558547081cf90544846b409f /drivers/net/sfc/siena.c | |
| parent | c0786693404cffd80ca3cb6e75ee7b35186b2825 (diff) | |
sfc: Wait at most 10ms for the MC to finish reading out MAC statistics
The original code would wait indefinitely if MAC stats DMA failed.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/sfc/siena.c')
| -rw-r--r-- | drivers/net/sfc/siena.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/net/sfc/siena.c b/drivers/net/sfc/siena.c index 38dcc42c4f79..e0c46f59d1f8 100644 --- a/drivers/net/sfc/siena.c +++ b/drivers/net/sfc/siena.c @@ -456,8 +456,17 @@ static int siena_try_update_nic_stats(struct efx_nic *efx) 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) |