stmmac: add memory barriers at appropriate places
This patch, provided by ST SPEAr developers,
has fixed a problem raised on ARM CA9 where
happened that the dma_transmission was enabled before
the dma descriptors were properly filled. To guarantee this
data memory barriers have been explicity used in the driver.
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/stmmac/stmmac_main.c b/drivers/net/stmmac/stmmac_main.c
index d4adc80..c8c9e5b 100644
--- a/drivers/net/stmmac/stmmac_main.c
+++ b/drivers/net/stmmac/stmmac_main.c
@@ -1045,6 +1045,7 @@
len, DMA_TO_DEVICE);
priv->tx_skbuff[entry] = NULL;
priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion);
+ wmb();
priv->hw->desc->set_tx_owner(desc);
}
@@ -1056,6 +1057,9 @@
if (likely(priv->tm->enable))
priv->hw->desc->clear_tx_ic(desc);
#endif
+
+ wmb();
+
/* To avoid raise condition */
priv->hw->desc->set_tx_owner(first);
@@ -1118,6 +1122,7 @@
}
RX_DBG(KERN_INFO "\trefill entry #%d\n", entry);
}
+ wmb();
priv->hw->desc->set_rx_owner(p + entry);
}
}