sfc: Insert read memory barrier after checking MAC statistics flag

This prevents speculative reading of the statistics before the
completion flag.

From: Neil Turton <nturton@solarflare.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Ben Hutchings 2008-09-01 12:50:08 +01:00 committed by Jeff Garzik
parent a620e134e9
commit 1d0680fd62

View file

@ -1953,8 +1953,10 @@ int falcon_dma_stats(struct efx_nic *efx, unsigned int done_offset)
/* Wait for transfer to complete */
for (i = 0; i < 400; i++) {
if (*(volatile u32 *)dma_done == FALCON_STATS_DONE)
if (*(volatile u32 *)dma_done == FALCON_STATS_DONE) {
rmb(); /* Ensure the stats are valid. */
return 0;
}
udelay(10);
}