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b44: tx bounce sizing.

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No need to grap full size MTU buffer for possibly small transmit
bounce buffers.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Stephen Hemminger 2007-06-04 13:25:38 -07:00 committed by Jeff Garzik
parent a72a817973
commit f65a71775c
1 changed files with 5 additions and 7 deletions
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12
drivers/net/b44.c
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@ -69,7 +69,6 @@
#define NEXT_TX(N) (((N) + 1) & (B44_TX_RING_SIZE - 1)) #define NEXT_TX(N) (((N) + 1) & (B44_TX_RING_SIZE - 1))
#define RX_PKT_BUF_SZ (1536 + bp->rx_offset + 64) #define RX_PKT_BUF_SZ (1536 + bp->rx_offset + 64)
#define TX_PKT_BUF_SZ (B44_MAX_MTU + ETH_HLEN + 8)
/* minimum number of free TX descriptors required to wake up TX process */ /* minimum number of free TX descriptors required to wake up TX process */
#define B44_TX_WAKEUP_THRESH (B44_TX_RING_SIZE / 4) #define B44_TX_WAKEUP_THRESH (B44_TX_RING_SIZE / 4)
@ -968,7 +967,6 @@ static void b44_tx_timeout(struct net_device *dev)
static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev) static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev)
{ {
struct b44 *bp = netdev_priv(dev); struct b44 *bp = netdev_priv(dev);
struct sk_buff *bounce_skb;
int rc = NETDEV_TX_OK; int rc = NETDEV_TX_OK;
dma_addr_t mapping; dma_addr_t mapping;
u32 len, entry, ctrl; u32 len, entry, ctrl;
@ -986,12 +984,13 @@ static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev)
mapping = pci_map_single(bp->pdev, skb->data, len, PCI_DMA_TODEVICE); mapping = pci_map_single(bp->pdev, skb->data, len, PCI_DMA_TODEVICE);
if (dma_mapping_error(mapping) || mapping + len > DMA_30BIT_MASK) { if (dma_mapping_error(mapping) || mapping + len > DMA_30BIT_MASK) {
struct sk_buff *bounce_skb;
/* Chip can't handle DMA to/from >1GB, use bounce buffer */ /* Chip can't handle DMA to/from >1GB, use bounce buffer */
if (!dma_mapping_error(mapping)) if (!dma_mapping_error(mapping))
pci_unmap_single(bp->pdev, mapping, len, PCI_DMA_TODEVICE); pci_unmap_single(bp->pdev, mapping, len, PCI_DMA_TODEVICE);
bounce_skb = __dev_alloc_skb(TX_PKT_BUF_SZ, bounce_skb = __dev_alloc_skb(len, GFP_ATOMIC | GFP_DMA);
GFP_ATOMIC|GFP_DMA);
if (!bounce_skb) if (!bounce_skb)
goto err_out; goto err_out;
@ -1000,13 +999,12 @@ static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev)
if (dma_mapping_error(mapping) || mapping + len > DMA_30BIT_MASK) { if (dma_mapping_error(mapping) || mapping + len > DMA_30BIT_MASK) {
if (!dma_mapping_error(mapping)) if (!dma_mapping_error(mapping))
pci_unmap_single(bp->pdev, mapping, pci_unmap_single(bp->pdev, mapping,
len, PCI_DMA_TODEVICE); len, PCI_DMA_TODEVICE);
dev_kfree_skb_any(bounce_skb); dev_kfree_skb_any(bounce_skb);
goto err_out; goto err_out;
} }
skb_copy_from_linear_data(skb, skb_put(bounce_skb, len), skb_copy_from_linear_data(skb, skb_put(bounce_skb, len), len);
skb->len);
dev_kfree_skb_any(skb); dev_kfree_skb_any(skb);
skb = bounce_skb; skb = bounce_skb;
} }