MACB: clear transmit buffers properly on transmit underrun (bdcba151) · Commits · 戴 / test

Initially transmit buffer pointers were only reset. But buffer descriptors were possibly still set as ready, and buffer in upper layer was not freed. This caused driver hang under big load. Now reset clean properly the buffer descriptor and freed upper layer. Signed-off-by:

Gregory CLEMENT <gclement00@gmail.com> Signed-off-by:

Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/net/macb.c

+24 −1

Original line number	Diff line number	Diff line
		@@ -307,8 +307,31 @@ static void macb_tx(struct macb *bp)
		(unsigned long)status);

		if (status & MACB_BIT(UND)) {
		int i;
		printk(KERN_ERR "%s: TX underrun, resetting buffers\n",
		bp->dev->name);

		head = bp->tx_head;

		/Mark all the buffer as used to avoid sending a lost buffer/
		for (i = 0; i < TX_RING_SIZE; i++)
		bp->tx_ring[i].ctrl = MACB_BIT(TX_USED);

		/* free transmit buffer in upper layer*/
		for (tail = bp->tx_tail; tail != head; tail = NEXT_TX(tail)) {
		struct ring_info *rp = &bp->tx_skb[tail];
		struct sk_buff *skb = rp->skb;

		BUG_ON(skb == NULL);

		rmb();

		dma_unmap_single(&bp->pdev->dev, rp->mapping, skb->len,
		DMA_TO_DEVICE);
		rp->skb = NULL;
		dev_kfree_skb_irq(skb);
		}

		bp->tx_head = bp->tx_tail = 0;
		}

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