Spidernet Memory barrier

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: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/spider_net.c b/drivers/net/spider_net.c
index 67bbd7b..3bf4b9b 100644 (file)
--- a/drivers/net/spider_net.c
+++ b/drivers/net/spider_net.c
@@ -419,6 +419,7 @@ spider_net_prepare_rx_descr(struct spider_net_card *card,
                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;
        }