From: Stefan Bader <stefan.bader@canonical•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: David Miller <davem@davemloft•net>, netdev <netdev@vger•kernel.org>
Subject: Re: [PATCH] net: dont use __netdev_alloc_skb for bounce buffer
Date: Mon, 02 Jul 2012 22:03:42 +0200 [thread overview]
Message-ID: <4FF1FE9E.7020709@canonical.com> (raw)
In-Reply-To: <1341254172.22621.456.camel@edumazet-glaptop>
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I can confirm that, with the below patch applied, at least the b44 regression is
fixed and network is usable again.
-Stefan
On 02.07.2012 20:36, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google•com>
>
> commit a1c7fff7e1 (net: netdev_alloc_skb() use build_skb()) broke b44 on
> some 64bit machines.
>
> It appears b44 and b43 use __netdev_alloc_skb() instead of alloc_skb()
> for their bounce buffers.
>
> There is no need to add an extra NET_SKB_PAD reservation for bounce
> buffers :
>
> - In TX path, NET_SKB_PAD is useless
>
> - In RX path in b44, we force a copy of incoming frames if
> GFP_DMA allocations were needed.
>
> Reported-and-bisected-by: Stefan Bader <stefan.bader@canonical•com>
> Signed-off-by: Eric Dumazet <edumazet@google•com>
> ---
> drivers/net/ethernet/broadcom/b44.c | 4 ++--
> drivers/net/wireless/b43legacy/dma.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c
> index 46b8b7d..d09c6b5 100644
> --- a/drivers/net/ethernet/broadcom/b44.c
> +++ b/drivers/net/ethernet/broadcom/b44.c
> @@ -656,7 +656,7 @@ static int b44_alloc_rx_skb(struct b44 *bp, int src_idx, u32 dest_idx_unmasked)
> dma_unmap_single(bp->sdev->dma_dev, mapping,
> RX_PKT_BUF_SZ, DMA_FROM_DEVICE);
> dev_kfree_skb_any(skb);
> - skb = __netdev_alloc_skb(bp->dev, RX_PKT_BUF_SZ, GFP_ATOMIC|GFP_DMA);
> + skb = alloc_skb(RX_PKT_BUF_SZ, GFP_ATOMIC | GFP_DMA);
> if (skb == NULL)
> return -ENOMEM;
> mapping = dma_map_single(bp->sdev->dma_dev, skb->data,
> @@ -967,7 +967,7 @@ static netdev_tx_t b44_start_xmit(struct sk_buff *skb, struct net_device *dev)
> dma_unmap_single(bp->sdev->dma_dev, mapping, len,
> DMA_TO_DEVICE);
>
> - bounce_skb = __netdev_alloc_skb(dev, len, GFP_ATOMIC | GFP_DMA);
> + bounce_skb = alloc_skb(len, GFP_ATOMIC | GFP_DMA);
> if (!bounce_skb)
> goto err_out;
>
> diff --git a/drivers/net/wireless/b43legacy/dma.c b/drivers/net/wireless/b43legacy/dma.c
> index f1f8bd0..c8baf02 100644
> --- a/drivers/net/wireless/b43legacy/dma.c
> +++ b/drivers/net/wireless/b43legacy/dma.c
> @@ -1072,7 +1072,7 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
> meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
> /* create a bounce buffer in zone_dma on mapping failure. */
> if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
> - bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
> + bounce_skb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
> if (!bounce_skb) {
> ring->current_slot = old_top_slot;
> ring->used_slots = old_used_slots;
>
>
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next prev parent reply other threads:[~2012-07-02 20:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-02 18:36 [PATCH] net: dont use __netdev_alloc_skb for bounce buffer Eric Dumazet
2012-07-02 20:03 ` Stefan Bader [this message]
2012-07-09 6:52 ` David Miller
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