From: Grant Grundler <grundler@parisc-linux.org>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: David Miller <davem@davemloft.net>,
Jarek Poplawski <jarkao2@gmail.com>,
Grant Grundler <grundler@parisc-linux.org>,
netdev@vger.kernel.org
Subject: Re: [PATCH 06/11] de2104x: fix DMA sync_single length error
Date: Thu, 21 Jan 2010 18:02:44 -0700 [thread overview]
Message-ID: <20100122010244.GA27529@lackof.org> (raw)
In-Reply-To: <20100120204559.177544514@vyatta.com>
On Wed, Jan 20, 2010 at 12:45:05PM -0800, Stephen Hemminger wrote:
> The DMA api requires that the full mapping be sync'd when
> copying frame. First found by Jarek on sky2.
Are you referring to the example code in Documentation/PCI/PCI-DMA-mapping.txt?
I don't see any "Use the full mapping" statement otherwise.
Is there a DMA HW implementation that requires the syncing full buffer?
I think it would be interesting to point that out in the commit comments
since other NIC drivers are likely to also have this issue as well.
I have no objection to this patch. Just want to be clear why
it's being pushed.
Please added Acked-by: Grant Grundler <grundler@parisc-linux.org>
thanks,
grant
>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>
> --- a/drivers/net/tulip/de2104x.c 2010-01-20 11:41:20.878138314 -0800
> +++ b/drivers/net/tulip/de2104x.c 2010-01-20 11:41:59.858847380 -0800
> @@ -456,11 +456,13 @@ static void de_rx (struct de_private *de
> buflen, PCI_DMA_FROMDEVICE);
> de->rx_skb[rx_tail].skb = copy_skb;
> } else {
> - pci_dma_sync_single_for_cpu(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
> + pci_dma_sync_single_for_cpu(de->pdev, mapping,
> + buflen, PCI_DMA_FROMDEVICE);
> skb_reserve(copy_skb, RX_OFFSET);
> skb_copy_from_linear_data(skb, skb_put(copy_skb, len),
> len);
> - pci_dma_sync_single_for_device(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
> + pci_dma_sync_single_for_device(de->pdev, mapping,
> + buflen, PCI_DMA_FROMDEVICE);
>
> /* We'll reuse the original ring buffer. */
> skb = copy_skb;
>
> --
next prev parent reply other threads:[~2010-01-22 1:02 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-20 20:44 [PATCH 00/11] DMA sync errors Stephen Hemminger
2010-01-20 20:45 ` [PATCH 01/11] tg3: fix DMA sync_single length error Stephen Hemminger
2010-01-20 20:45 ` [PATCH 02/11] sky2: " Stephen Hemminger
2010-01-20 21:32 ` Jarek Poplawski
2010-01-20 22:52 ` David Miller
2010-01-20 23:21 ` Jarek Poplawski
2010-01-20 23:34 ` David Miller
2010-01-20 23:41 ` David Miller
2010-01-20 23:59 ` Jarek Poplawski
2010-01-21 0:04 ` Stephen Hemminger
2010-01-21 0:15 ` David Miller
2010-01-20 23:52 ` Jarek Poplawski
2010-01-20 23:56 ` David Miller
2010-01-20 20:45 ` [PATCH 03/11] skge: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 04/11] r8169: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 05/11] rrunner: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 06/11] de2104x: " Stephen Hemminger
2010-01-22 1:02 ` Grant Grundler [this message]
2010-01-22 1:12 ` Stephen Hemminger
2010-01-20 20:45 ` [PATCH 07/11] sungem: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 08/11] sunhme: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 09/11] cassini: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 10/11] cxgb3: " Stephen Hemminger
2010-01-20 20:45 ` [PATCH 11/11] ipoib: " Stephen Hemminger
2010-01-20 22:46 ` [PATCH 00/11] DMA sync errors David Miller
2010-01-20 23:28 ` Stephen Hemminger
2010-01-21 0:18 ` David Miller
2010-01-21 0:34 ` Stephen Hemminger
2010-01-21 0:36 ` David Miller
2010-01-21 12:44 ` Jarek Poplawski
2010-01-21 13:12 ` David Miller
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