diff options
| author | Havard Skinnemoen <havard@skinnemoen.net> | 2012-10-31 06:04:51 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-11-01 11:45:56 -0400 |
| commit | 03dbe05fe4f24fdca4aa6db59ee8341880ec8090 (patch) | |
| tree | 28a32edceddfa5bdb8eae33da44bab04fd157b16 /drivers | |
| parent | 140b7552fdff04bbceeb842f0e04f0b4015fe97b (diff) | |
| download | linux-3.10-03dbe05fe4f24fdca4aa6db59ee8341880ec8090.tar.gz linux-3.10-03dbe05fe4f24fdca4aa6db59ee8341880ec8090.tar.bz2 linux-3.10-03dbe05fe4f24fdca4aa6db59ee8341880ec8090.zip | |
net/macb: memory barriers cleanup
Remove a couple of unneeded barriers and document the remaining ones.
Signed-off-by: Havard Skinnemoen <havard@skinnemoen.net>
[nicolas.ferre@atmel.com: split patch in topics]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/cadence/macb.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index 0931cb7469d..e7f554dfe50 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -373,7 +373,9 @@ static void macb_tx(struct macb *bp) BUG_ON(skb == NULL); + /* Make hw descriptor updates visible to CPU */ rmb(); + bufstat = bp->tx_ring[tail].ctrl; if (!(bufstat & MACB_BIT(TX_USED))) @@ -416,7 +418,10 @@ static int macb_rx_frame(struct macb *bp, unsigned int first_frag, if (frag == last_frag) break; } + + /* Make descriptor updates visible to hardware */ wmb(); + return 1; } @@ -437,12 +442,14 @@ static int macb_rx_frame(struct macb *bp, unsigned int first_frag, frag_len); offset += RX_BUFFER_SIZE; bp->rx_ring[frag].addr &= ~MACB_BIT(RX_USED); - wmb(); if (frag == last_frag) break; } + /* Make descriptor updates visible to hardware */ + wmb(); + skb->protocol = eth_type_trans(skb, bp->dev); bp->stats.rx_packets++; @@ -462,6 +469,8 @@ static void discard_partial_frame(struct macb *bp, unsigned int begin, for (frag = begin; frag != end; frag = NEXT_RX(frag)) bp->rx_ring[frag].addr &= ~MACB_BIT(RX_USED); + + /* Make descriptor updates visible to hardware */ wmb(); /* @@ -480,7 +489,9 @@ static int macb_rx(struct macb *bp, int budget) for (; budget > 0; tail = NEXT_RX(tail)) { u32 addr, ctrl; + /* Make hw descriptor updates visible to CPU */ rmb(); + addr = bp->rx_ring[tail].addr; ctrl = bp->rx_ring[tail].ctrl; @@ -675,6 +686,8 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev) bp->tx_ring[entry].addr = mapping; bp->tx_ring[entry].ctrl = ctrl; + + /* Make newly initialized descriptor visible to hardware */ wmb(); entry = NEXT_TX(entry); @@ -783,9 +796,6 @@ static void macb_init_rings(struct macb *bp) static void macb_reset_hw(struct macb *bp) { - /* Make sure we have the write buffer for ourselves */ - wmb(); - /* * Disable RX and TX (XXX: Should we halt the transmission * more gracefully?) |