Commit 97bc477c authored by Phil Sutter's avatar Phil Sutter Committed by David S. Miller
Browse files

korina: fix handling tx_chain_tail 



Originally this must have been a rewrite error when introducing
'chain_index'. But the original driver did not use the previous chain
item everywhere: when altering the address tx_chain_tail points to, it
should move forward, not backwards.
Also this is not an "index" but rather the penultimate element in the
chain, so rename it accordingly.

Signed-off-by: default avatarPhil Sutter <n0-1@freewrt.org>
Acked-by: default avatarFlorian Fainelli <florian@openwrt.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 60d3f982

drivers/net/korina.c

+11 −11
Original line number Diff line number Diff line
@@ -199,7 +199,7 @@ static int korina_send_packet(struct sk_buff *skb, struct net_device *dev) 
	struct korina_private *lp = netdev_priv(dev);

	unsigned long flags;

	u32 length;

	u32 chain_index;

	u32 chain_prev, chain_next;

	struct dma_desc *td;



	spin_lock_irqsave(&lp->lock, flags);
@@ -231,8 +231,8 @@ static int korina_send_packet(struct sk_buff *skb, struct net_device *dev) 
	/* Setup the transmit descriptor. */

	dma_cache_inv((u32) td, sizeof(*td));

	td->ca = CPHYSADDR(skb->data);

	chain_index = (lp->tx_chain_tail - 1) &

			KORINA_TDS_MASK;

	chain_prev = (lp->tx_chain_tail - 1) & KORINA_TDS_MASK;

	chain_next = (lp->tx_chain_tail + 1) & KORINA_TDS_MASK;



	if (readl(&(lp->tx_dma_regs->dmandptr)) == 0) {

		if (lp->tx_chain_status == desc_empty) {
@@ -240,7 +240,7 @@ static int korina_send_packet(struct sk_buff *skb, struct net_device *dev) 
			td->control = DMA_COUNT(length) |

					DMA_DESC_COF | DMA_DESC_IOF;

			/* Move tail */

			lp->tx_chain_tail = chain_index;

			lp->tx_chain_tail = chain_next;

			/* Write to NDPTR */

			writel(CPHYSADDR(&lp->td_ring[lp->tx_chain_head]),

					&lp->tx_dma_regs->dmandptr);
@@ -251,12 +251,12 @@ static int korina_send_packet(struct sk_buff *skb, struct net_device *dev) 
			td->control = DMA_COUNT(length) |

					DMA_DESC_COF | DMA_DESC_IOF;

			/* Link to prev */

			lp->td_ring[chain_index].control &=

			lp->td_ring[chain_prev].control &=

					~DMA_DESC_COF;

			/* Link to prev */

			lp->td_ring[chain_index].link =  CPHYSADDR(td);

			lp->td_ring[chain_prev].link =  CPHYSADDR(td);

			/* Move tail */

			lp->tx_chain_tail = chain_index;

			lp->tx_chain_tail = chain_next;

			/* Write to NDPTR */

			writel(CPHYSADDR(&lp->td_ring[lp->tx_chain_head]),

					&(lp->tx_dma_regs->dmandptr));
@@ -270,17 +270,17 @@ static int korina_send_packet(struct sk_buff *skb, struct net_device *dev) 
			td->control = DMA_COUNT(length) |

					DMA_DESC_COF | DMA_DESC_IOF;

			/* Move tail */

			lp->tx_chain_tail = chain_index;

			lp->tx_chain_tail = chain_next;

			lp->tx_chain_status = desc_filled;

			netif_stop_queue(dev);

		} else {

			/* Update tail */

			td->control = DMA_COUNT(length) |

					DMA_DESC_COF | DMA_DESC_IOF;

			lp->td_ring[chain_index].control &=

			lp->td_ring[chain_prev].control &=

					~DMA_DESC_COF;

			lp->td_ring[chain_index].link =  CPHYSADDR(td);

			lp->tx_chain_tail = chain_index;

			lp->td_ring[chain_prev].link =  CPHYSADDR(td);

			lp->tx_chain_tail = chain_next;

		}

	}

	dma_cache_wback((u32) td, sizeof(*td));

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