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Commit 03dbe05f authored by Havard Skinnemoen's avatar Havard Skinnemoen Committed by David S. Miller
Browse files

net/macb: memory barriers cleanup 



Remove a couple of unneeded barriers and document the remaining ones.

Signed-off-by: default avatarHavard Skinnemoen <havard@skinnemoen.net>
[nicolas.ferre@atmel.com: split patch in topics]
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: default avatarJoachim Eastwood <manabian@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 140b7552

drivers/net/ethernet/cadence/macb.c

+14 −4
Original line number Diff line number Diff line
@@ -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?)