Re: Bug - regression - Via velocity interface coming up freezes kernel

[Michele Baldessari <michele@acksyn.org>]

Hi Francois,

On Mon, Sep 23, 2013 at 12:11:09AM +0200, Francois Romieu wrote:
> Dirk Kraft <dirk.kraft@gmail.com> :
> [...]
> > I observe problems with my machine freezing when bringing up the
> > network interface (via velocity based). Detailed report below.
> > 
> > First message was rejected because of html. Julia Lawall, sorry about
> > sending multiple copies.
> > 
> > [1.] One line summary of the problem:
> > Via_velocity interface coming up freezes kernel - WARNING: CPU: 0 PID:
> > 1529 at /build/buildd/linux-3.11.0/kernel/softirq.c:159
> > local_bh_enable+0x60/0x90()
> 
> netif_receive_skb with irq disabled ?
> 
> You can try this one as a wild guess before I have more time to analyze.
> 
> diff --git a/drivers/net/ethernet/via/via-velocity.c b/drivers/net/ethernet/via/via-velocity.c
> index d022bf9..64c42be 100644
> --- a/drivers/net/ethernet/via/via-velocity.c
> +++ b/drivers/net/ethernet/via/via-velocity.c
> @@ -2172,16 +2172,13 @@ static int velocity_poll(struct napi_struct *napi, int budget)
>  	unsigned int rx_done;
>  	unsigned long flags;
>  
> -	spin_lock_irqsave(&vptr->lock, flags);
>  	/*
>  	 * Do rx and tx twice for performance (taken from the VIA
>  	 * out-of-tree driver).
>  	 */
> -	rx_done = velocity_rx_srv(vptr, budget / 2);
> -	velocity_tx_srv(vptr);
> -	rx_done += velocity_rx_srv(vptr, budget - rx_done);
> +	rx_done = velocity_rx_srv(vptr, budget);
> +	spin_lock_irqsave(&vptr->lock, flags);
>  	velocity_tx_srv(vptr);
> -
>  	/* If budget not fully consumed, exit the polling mode */
>  	if (rx_done < budget) {
>  		napi_complete(napi);

any chance you can submit this officially? Or does this patch need some
more work?

Two people confirmed it fixed the issue for them on netdev and one
on Fedora's bugzilla so far.

Thanks,
Michele
-- 
Michele Baldessari            <michele@acksyn.org>
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