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

PATCH Applied Fabio Estevam 2 participants 2 messages Mar 13, 2015

Subsystems (3)
Networking Network drivers Freescale i.MX / MXC FEC driver
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Fabio Estevam

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#0 lore raw

PATCH 1/1 Revert "net: fec: fix the warning found by dma debug"

From: Fabio Estevam <[email protected]>

This reverts commit 2b995f63987013bacde99168218f9c7b252bdcf1.

Панов Андрей reported the following regression:

"Commit 2b995f63987013bacde99168218f9c7b252bdcf1 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 Панов Андрей <[email protected]>
Signed-off-by Fabio Estevam <[email protected]>
---
 drivers/net/ethernet/freescale/fec_main.c | 34 ++++++++++---------------------
 1 file changed, 11 insertions(+), 23 deletions(-)
drivers/net/ethernet/freescale/fec_main.c +11 -23
index 787db50..78e1ce0 100644
@@ -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++) {
-			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)
-				bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);
-		}
+		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 (!skb) {
+			bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);
+			continue;
+		}
 
 		/* Check for errors. */
 		if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC |
Signature · 1 line
1.9.1
maintainer Applied
#1 lore raw

From: Fabio Estevam <[email protected]>
Date: Fri, 13 Mar 2015 14:07:54 -0300

Quoted 21 lines

From: Fabio Estevam <[email protected]>

This reverts commit 2b995f63987013bacde99168218f9c7b252bdcf1.

Панов Андрей reported the following regression:

"Commit 2b995f63987013bacde99168218f9c7b252bdcf1 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.

Quoted 6 lines

I use an i.MX6 Quad board.

If this commit is reverted, all works fine."

Reported-by Панов Андрей <[email protected]>
Signed-off-by Fabio Estevam <[email protected]>

Applied, thanks.