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:0.356 / U:0.460 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site