Commit 1d0680fd authored Sep 01, 2008 by Ben Hutchings Committed by Jeff Garzik Sep 24, 2008

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>

parent a620e134

drivers/net/sfc/falcon.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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);
		}