From: Ben Hutchings <ben@decadent.org.uk>
To: Soren Brinkmann <soren.brinkmann@xilinx.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Vinod Koul <vinod.koul@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Michal Simek <michal.simek@xilinx.com>
Subject: Re: [PATCH v2 1/2] net: macb: Check DMA mappings for error
Date: Thu, 27 Feb 2014 23:57:39 +0000 [thread overview]
Message-ID: <1393545459.14067.79.camel@deadeye.wl.decadent.org.uk> (raw)
In-Reply-To: <1393538285-28297-1-git-send-email-soren.brinkmann@xilinx.com>
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On Thu, 2014-02-27 at 13:58 -0800, Soren Brinkmann wrote:
[...]
> diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
> index 3190d38e16fb..a9c2ccfc1740 100644
> --- a/drivers/net/ethernet/cadence/macb.c
> +++ b/drivers/net/ethernet/cadence/macb.c
> @@ -632,11 +632,16 @@ static void gem_rx_refill(struct macb *bp)
> "Unable to allocate sk_buff\n");
> break;
> }
> - bp->rx_skbuff[entry] = skb;
>
> /* now fill corresponding descriptor entry */
> paddr = dma_map_single(&bp->pdev->dev, skb->data,
> bp->rx_buffer_size, DMA_FROM_DEVICE);
> + if (dma_mapping_error(&bp->pdev->dev, paddr)) {
> + dev_kfree_skb(skb);
> + break;
> + }
> +
> + bp->rx_skbuff[entry] = skb;
>
> if (entry == RX_RING_SIZE - 1)
> paddr |= MACB_BIT(RX_WRAP);
> @@ -1040,6 +1045,10 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
A bit more context:
entry = macb_tx_ring_wrap(bp->tx_head);
bp->tx_head++;
> netdev_vdbg(bp->dev, "Allocated ring entry %u\n", entry);
> mapping = dma_map_single(&bp->pdev->dev, skb->data,
> len, DMA_TO_DEVICE);
> + if (dma_mapping_error(&bp->pdev->dev, mapping)) {
> + kfree_skb(skb);
> + goto unlock;
> + }
You need to move the bp->tx_head increment below this error check.
Sorry I didn't spot this the first time.
Ben.
> tx_skb = &bp->tx_skb[entry];
> tx_skb->skb = skb;
> @@ -1066,6 +1075,7 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
> if (CIRC_SPACE(bp->tx_head, bp->tx_tail, TX_RING_SIZE) < 1)
> netif_stop_queue(dev);
>
> +unlock:
> spin_unlock_irqrestore(&bp->lock, flags);
>
> return NETDEV_TX_OK;
--
Ben Hutchings
It is easier to change the specification to fit the program than vice versa.
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next prev parent reply other threads:[~2014-02-27 23:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-27 21:58 Soren Brinkmann
2014-02-27 21:58 ` [PATCH v2 2/2] net: macb: DMA-unmap full rx-buffer Soren Brinkmann
2014-02-27 23:57 ` Ben Hutchings [this message]
2014-03-01 0:24 ` [PATCH v2 1/2] net: macb: Check DMA mappings for error Sören Brinkmann
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