From: Fugang Duan <B38611@freescale.com>
Date: Wed, 21 Dec 2011 10:32:11 +0000 (+0800)
Subject: ENGR00170784 - FEC : dma skb buffer map is not used rightly.
X-Git-Tag: v3.0.35-fsl~1709
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=42a3e8a625c03cbddb7d5781e5f3a1f998f27ec8;p=karo-tx-linux.git

ENGR00170784 - FEC : dma skb buffer map is not used rightly.

Enable "CONFIG_DMA_API_DEBUG" in kernel, and system print:

DMA-API: device driver tries to free DMA memory it has not
allocated [device address=0x0000000046688020]...[<80222494>]
(debug_dma_unmap_page+0x8c/0x98) from [<802a36a0>]
(fec_enet_interrupt+0x430/0x5ac)

Correct the usage of "dma_map_single" function.

Signed-off-by: Fugang Duan  <B38611@freescale.com>
---

diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index b56a623875d2..c3cb63799c73 100755
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -401,7 +401,8 @@ fec_enet_tx(struct net_device *ndev)
 		if (bdp == fep->cur_tx && fep->tx_full == 0)
 			break;
 
-		dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
+		if (bdp->cbd_bufaddr)
+			dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
 				FEC_ENET_TX_FRSIZE, DMA_TO_DEVICE);
 		bdp->cbd_bufaddr = 0;
 
@@ -542,7 +543,8 @@ fec_enet_rx(struct net_device *ndev)
 		ndev->stats.rx_bytes += pkt_len;
 		data = (__u8*)__va(bdp->cbd_bufaddr);
 
-		dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
+		if (bdp->cbd_bufaddr)
+			dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
 				FEC_ENET_TX_FRSIZE, DMA_FROM_DEVICE);
 
 		if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
@@ -1089,7 +1091,6 @@ fec_enet_open(struct net_device *ndev)
 	/* I should reset the ring buffers here, but I don't yet know
 	 * a simple way to do that.
 	 */
-
 	if (!clk_get_usecount(fep->clk))
 		clk_enable(fep->clk);
 	ret = fec_enet_alloc_buffers(ndev);
@@ -1290,6 +1291,7 @@ static int fec_enet_init(struct net_device *ndev)
 
 		/* Initialize the BD for every fragment in the page. */
 		bdp->cbd_sc = 0;
+		bdp->cbd_bufaddr = 0;
 		bdp++;
 	}