From: Francois Romieu Date: Tue, 20 Feb 2007 21:20:51 +0000 (+0100) Subject: r8169: confusion between hardware and IP header alignment X-Git-Tag: v2.6.23-rc1~1201^2~14 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=864022344caf43dab7fa5219152280d056c6e051;p=linux-2.6 r8169: confusion between hardware and IP header alignment The rx copybreak part is straightforward. The align field in struct rtl_cfg_info is related to the alignment requirements of the DMA operation. Its value is set at 2 to limit the scale of possible regression but my old v1.21 8169 datasheet claims a 8 bytes requirements (which never appeared in the driver, of course) and the 8101/8168 go with a plain 8 bytes alignment. Signed-off-by: Francois Romieu Cc: Edward Hsu --- diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c index 9c49d910c0..a6fea192ff 100644 --- a/drivers/net/r8169.c +++ b/drivers/net/r8169.c @@ -1490,7 +1490,7 @@ static const struct rtl_cfg_info { [RTL_CFG_0] = { .hw_start = rtl_hw_start_8169, .region = 1, - .align = NET_IP_ALIGN, + .align = 2, .intr_event = SYSErr | LinkChg | RxOverflow | RxFIFOOver | TxErr | TxOK | RxOK | RxErr, .napi_event = RxFIFOOver | TxErr | TxOK | RxOK | RxOverflow @@ -2649,8 +2649,7 @@ static inline void rtl8169_rx_csum(struct sk_buff *skb, struct RxDesc *desc) } static inline bool rtl8169_try_rx_copy(struct sk_buff **sk_buff, int pkt_size, - struct pci_dev *pdev, dma_addr_t addr, - unsigned int align) + struct pci_dev *pdev, dma_addr_t addr) { struct sk_buff *skb; bool done = false; @@ -2658,12 +2657,12 @@ static inline bool rtl8169_try_rx_copy(struct sk_buff **sk_buff, int pkt_size, if (pkt_size >= rx_copybreak) goto out; - skb = dev_alloc_skb(pkt_size + align); + skb = dev_alloc_skb(pkt_size + NET_IP_ALIGN); if (!skb) goto out; pci_dma_sync_single_for_cpu(pdev, addr, pkt_size, PCI_DMA_FROMDEVICE); - skb_reserve(skb, (align - 1) & (unsigned long)skb->data); + skb_reserve(skb, NET_IP_ALIGN); skb_copy_from_linear_data(*sk_buff, skb->data, pkt_size); *sk_buff = skb; done = true; @@ -2732,8 +2731,7 @@ rtl8169_rx_interrupt(struct net_device *dev, struct rtl8169_private *tp, rtl8169_rx_csum(skb, desc); - if (rtl8169_try_rx_copy(&skb, pkt_size, pdev, addr, - tp->align)) { + if (rtl8169_try_rx_copy(&skb, pkt_size, pdev, addr)) { pci_dma_sync_single_for_device(pdev, addr, pkt_size, PCI_DMA_FROMDEVICE); rtl8169_mark_to_asic(desc, tp->rx_buf_sz);