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Commit a2fe37b6 authored by Fabio Estevam's avatar Fabio Estevam Committed by David S. Miller
Browse files

Revert "net: fec: fix the warning found by dma debug" 



This reverts commit 2b995f63.

Панов Андрей reported the following regression:

"Commit 2b995f63 in 4.0.0-rc3 introduces a
nasty bug in transmit, corrupting packets.

To reproduce:

$ dd if=/dev/zero of=zeros bs=1M count=20
$ md5sum -b zeros
8f4e33f3dc3e414ff94e5fb6905cba8c *zeros

This checksum is correct.

Copy file "zeros" to another host with NFS, and it gets corrupted, checksum is
changed.
File should be big, small amounts of transmit isn't affected.

I use an i.MX6 Quad board.

If this commit is reverted, all works fine."

Reported-by: default avatarПанов Андрей <rockford@yandex.ru>
Signed-off-by: default avatarFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 40fb70f3

drivers/net/ethernet/freescale/fec_main.c

+11 −23
Original line number Diff line number Diff line
@@ -1189,13 +1189,12 @@ static void 
fec_enet_tx_queue(struct net_device *ndev, u16 queue_id)

{

	struct	fec_enet_private *fep;

	struct bufdesc *bdp, *bdp_t;

	struct bufdesc *bdp;

	unsigned short status;

	struct	sk_buff	*skb;

	struct fec_enet_priv_tx_q *txq;

	struct netdev_queue *nq;

	int	index = 0;

	int	i, bdnum;

	int	entries_free;



	fep = netdev_priv(ndev);
@@ -1216,29 +1215,18 @@ fec_enet_tx_queue(struct net_device *ndev, u16 queue_id) 
		if (bdp == txq->cur_tx)

			break;



		bdp_t = bdp;

		bdnum = 1;

		index = fec_enet_get_bd_index(txq->tx_bd_base, bdp_t, fep);

		skb = txq->tx_skbuff[index];

		while (!skb) {

			bdp_t = fec_enet_get_nextdesc(bdp_t, fep, queue_id);

			index = fec_enet_get_bd_index(txq->tx_bd_base, bdp_t, fep);

			skb = txq->tx_skbuff[index];

			bdnum++;

		}

		if (skb_shinfo(skb)->nr_frags &&

		    (status = bdp_t->cbd_sc) & BD_ENET_TX_READY)

			break;

		index = fec_enet_get_bd_index(txq->tx_bd_base, bdp, fep);



		for (i = 0; i < bdnum; i++) {

		skb = txq->tx_skbuff[index];

		txq->tx_skbuff[index] = NULL;

		if (!IS_TSO_HEADER(txq, bdp->cbd_bufaddr))

			dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,

					bdp->cbd_datlen, DMA_TO_DEVICE);

		bdp->cbd_bufaddr = 0;

			if (i < bdnum - 1)

		if (!skb) {

			bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);

			continue;

		}

		txq->tx_skbuff[index] = NULL;



		/* Check for errors. */

		if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC |