From: Linas Vepstas <linas@austin.ibm.com>

Add memory barrier to make sure that the rest of the RX descriptor state is
flushed to memory before we tell the hardware that its ready to go.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: James K Lewis <jklewis@us.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/net/spider_net.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN drivers/net/spider_net.c~spidernet-memory-barrier drivers/net/spider_net.c
--- a/drivers/net/spider_net.c~spidernet-memory-barrier
+++ a/drivers/net/spider_net.c
@@ -389,6 +389,7 @@ spider_net_prepare_rx_descr(struct spide
 		card->spider_stats.rx_iommu_map_error++;
 		descr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
 	} else {
+		wmb();
 		descr->dmac_cmd_status = SPIDER_NET_DESCR_CARDOWNED |
 					 SPIDER_NET_DMAC_NOINTR_COMPLETE;
 	}
_