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authorDeepak Sikri <deepak.sikri@st.com>2012-07-08 21:14:45 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-07-19 08:58:57 -0700
commitb98522a7cf0ff60bcf49330d9467089515cf9dad (patch)
treea46ff74e8e7acfdbb06ebd0382b25dedb61c5b3a
parent3cf16f7e388934d4458d0d6cebdf752e4424f226 (diff)
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stmmac: Fix for nfs hang on multiple reboot
commit 8e83989106562326bfd6aaf92174fe138efd026b upstream. It was observed that during multiple reboots nfs hangs. The status of receive descriptors shows that all the descriptors were in control of CPU, and none were assigned to DMA. Also the DMA status register confirmed that the Rx buffer is unavailable. This patch adds the fix for the same by adding the memory barriers to ascertain that the all instructions before enabling the Rx or Tx DMA are completed which involves the proper setting of the ownership bit in DMA descriptors. Signed-off-by: Deepak Sikri <deepak.sikri@st.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/ethernet/stmicro/stmmac/stmmac_main.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 48d56da62f0..9bdfaba4e30 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1158,6 +1158,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion);
wmb();
priv->hw->desc->set_tx_owner(desc);
+ wmb();
}
/* Interrupt on completition only for the latest segment */
@@ -1173,6 +1174,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
/* To avoid raise condition */
priv->hw->desc->set_tx_owner(first);
+ wmb();
priv->cur_tx++;
@@ -1236,6 +1238,7 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv)
}
wmb();
priv->hw->desc->set_rx_owner(p + entry);
+ wmb();
}
}