diff options
| author | Anatolij Gustschin <agust@denx.de> | 2010-02-26 15:00:49 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-02-27 13:34:36 +0300 |
| commit | cb395eaf439625f26c8527bb05bb905774a54c36 (patch) | |
| tree | 16a3f6c024230e65b37ddc8dae29b29d33820758 /drivers/net/fs_enet/fs_enet-main.c | |
| parent | 60ab4361adc188fb47da1c4892cc7a2bb621efef (diff) | |
| download | linux-cb395eaf439625f26c8527bb05bb905774a54c36.tar.xz | |
fs_enet: add FEC TX buffer alignment workaround for MPC5121
MPC5121 FEC requeries 4-byte alignmnent for TX data buffers.
This patch is a work around that copies misaligned tx packets
to an aligned skb before sending.
Signed-off-by: John Rigby <jcrigby@gmail.com>
Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/fs_enet/fs_enet-main.c')
| -rw-r--r-- | drivers/net/fs_enet/fs_enet-main.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c index 4297021214d1..0770e2f6da6b 100644 --- a/drivers/net/fs_enet/fs_enet-main.c +++ b/drivers/net/fs_enet/fs_enet-main.c @@ -580,6 +580,40 @@ void fs_cleanup_bds(struct net_device *dev) /**********************************************************************************/ +#ifdef CONFIG_FS_ENET_MPC5121_FEC +/* + * MPC5121 FEC requeries 4-byte alignment for TX data buffer! + */ +static struct sk_buff *tx_skb_align_workaround(struct net_device *dev, + struct sk_buff *skb) +{ + struct sk_buff *new_skb; + struct fs_enet_private *fep = netdev_priv(dev); + + /* Alloc new skb */ + new_skb = dev_alloc_skb(skb->len + 4); + if (!new_skb) { + if (net_ratelimit()) { + dev_warn(fep->dev, + "Memory squeeze, dropping tx packet.\n"); + } + return NULL; + } + + /* Make sure new skb is properly aligned */ + skb_align(new_skb, 4); + + /* Copy data to new skb ... */ + skb_copy_from_linear_data(skb, new_skb->data, skb->len); + skb_put(new_skb, skb->len); + + /* ... and free an old one */ + dev_kfree_skb_any(skb); + + return new_skb; +} +#endif + static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct fs_enet_private *fep = netdev_priv(dev); @@ -588,6 +622,19 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) u16 sc; unsigned long flags; +#ifdef CONFIG_FS_ENET_MPC5121_FEC + if (((unsigned long)skb->data) & 0x3) { + skb = tx_skb_align_workaround(dev, skb); + if (!skb) { + /* + * We have lost packet due to memory allocation error + * in tx_skb_align_workaround(). Hopefully original + * skb is still valid, so try transmit it later. + */ + return NETDEV_TX_BUSY; + } + } +#endif spin_lock_irqsave(&fep->tx_lock, flags); /* |