Commit 1d0680fd authored by Ben Hutchings's avatar Ben Hutchings Committed by Jeff Garzik
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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: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarJeff 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);

	}