Re: r8169: panic on 2.6.11

[Jon Mason <jdmason@us.ibm.com>]

On Friday 04 March 2005 05:02 pm, Francois Romieu wrote:
> Stephen Hemminger <shemminger@osdl.org> :
> [...]
>
> > NAPI is not enabled, it is the IRQ version. Hitting
> >
> > Added instrumentation:.
> >
> > skb=0xd1e28380 len=8172 head=d1e32000 data=d1e32012 tail=d1e33ffe
> > end=d1e32620
> >
> > Looks like the board is running back-to-back packets together, MTU is
> > 1500. No Jumbo frames exist on my little network and the gigabit switch
> > (Netgear) won't even take them.  Probably a chip bug.
>
> /me scratches head: play with the interframe gap ?
>
> > Need to add a check for len > mtu before processing?
>
> Please.
>
> diff -puN drivers/net/r8169.c~r8169-470 drivers/net/r8169.c
> --- linux-2.6.11/drivers/net/r8169.c~r8169-470 2005-03-04
> 22:51:35.038710839 +0100 +++ linux-2.6.11-fr/drivers/net/r8169.c 2005-03-04
> 23:16:29.422289316 +0100 @@ -2194,6 +2194,7 @@ rtl8169_rx_interrupt(struct
> net_device *
>     int pkt_size = (status & 0x00001FFF) - 4;
>     void (*pci_action)(struct pci_dev *, dma_addr_t,
>      size_t, int) = pci_dma_sync_single_for_device;
> +   static int show_size = 0;
>
>     rtl8169_rx_csum(skb, desc);
>
> @@ -2210,6 +2211,24 @@ rtl8169_rx_interrupt(struct net_device *
>     pci_action(tp->pci_dev, le64_to_cpu(desc->addr),
>         tp->rx_buf_sz, PCI_DMA_FROMDEVICE);
>
> +   if (pkt_size >= tp->rx_buf_sz) {
> +    show_size = 1;
> +    pkt_size = tp->rx_buf_sz;
> +   }

Shouldn't the above be dev->mtu (instead of tp->rx_buf_sz), otherwise there 
won't be enough room for ethernet header, CRC, etc.

> +
> +   if (show_size) {
> +    printk(KERN_INFO "%s: pkt_size=%d\n", dev->name,
> +           pkt_size);
> +    printk(KERN_INFO "%s: opts1= %08x\n", dev->name,
> +           desc->opts1);
> +    printk(KERN_INFO "%s: opts2= %08x\n", dev->name,
> +           desc->opts2);
> +    printk(KERN_INFO "%s: addrl= %08x\n", dev->name,
> +           (u32)desc->addr);
> +    printk(KERN_INFO "%s: addrh= %08x\n", dev->name,
> +           (u32)(desc->addr >> 32));
> +   }
> +
>     skb->dev = dev;
>     skb_put(skb, pkt_size);
>     skb->protocol = eth_type_trans(skb, dev);
>
> _