Commit cb395eaf authored by Anatolij Gustschin's avatar Anatolij Gustschin Committed by David S. Miller

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: default avatarJohn Rigby <jcrigby@gmail.com>
Signed-off-by: default avatarPiotr Ziecik <kosmo@semihalf.com>
Signed-off-by: default avatarWolfgang Denk <wd@denx.de>
Signed-off-by: default avatarAnatolij Gustschin <agust@denx.de>
Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 60ab4361
...@@ -580,6 +580,40 @@ void fs_cleanup_bds(struct net_device *dev) ...@@ -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) static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{ {
struct fs_enet_private *fep = netdev_priv(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) ...@@ -588,6 +622,19 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
u16 sc; u16 sc;
unsigned long flags; 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); spin_lock_irqsave(&fep->tx_lock, flags);
/* /*
......
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