Subject: Re: bugreport: The r8169.c driver is calling netif_receive_skb from hardirq and with interrupts off

From: Stephen Hemminger <[email-masked]>
Date: Mon, 14 Apr 2008 11:22:10 -0700

On Mon, 14 Apr 2008 11:01:16 -0700
Arjan van de Ven <[email-masked]> wrote:

> The r8169.c driver is calling netif_receive_skb from hardirq and with interrupts off,
> which seems to be invalid (the comments of netif_receive_skb) certainly say so.
> 
> The calltrace is like this:
> 
> packet_rcv
> netif_receive_skb
> rtl8168_rx_interrupt
> rtl8168_interrupt
> handle_IRQ_event
> handle_fasteoi_irq
> do_IRQ
> 
> 
> Which triggers a warning in packet_rcv() since that does a local_bh_enable(),
> which gives a WARN_ON if irqs are disabled (rightfully so it seems).
> 
> The code looks is in rtl8169_rx_interrupt() line 2832 and looks like
> 
>                          if (rtl8169_rx_vlan_skb(tp, desc, skb) < 0)
>                                  rtl8169_rx_skb(skb);
> 
> with
> #define rtl8169_rx_skb                  netif_receive_skb
> higher up in the file.
> 
> This is the 46th highest ranking warnon/oops report for 2.6.25-rc
> 

rtl8169_rx_skb is defined as netif_receive_skb only if NAPI is enabled.
But the backtrace has CONFIG_R8169_NAPI disabled.

I also concerned that the reset_task calls rx_interrupt with different locking
than normal interrupt.