Subject: Re: [PATCH 2.6.18] e1000: fix initialization irqs

From: Dmitry Mishin <[email-masked]>
Date: Wed, 22 Nov 2006 19:43:52 +0300

On Wednesday 22 November 2006 19:19, Auke Kok wrote:
> Dmitry Mishin wrote:
> > In case of irqpoll boot option set, e1000 may oops due to:
> > 1) e1000 register it's handler with e1000_request_irq
> > 2) spurious interrupt happens
> > 3) kernel tries to handle this interrupt with all available descs
> > 4) e1000_intr is called and oops due to not initialized clean_rx handler, 
> > because e1000_up is not called yet.
> > 
> > Solution is to initialize driver before handler registration.
> 
> I'm not so sure of that. even if we request our irq's to be routed it does not mean that 
> we told the NIC to send them. It would suggest that you might be haunted by the MSI 
> interrupts not working 100% correctly on some non-intel platform.
> 
> Now you're telling the NIC to send interrupts before we routed them I think.
> 
> If we _up() before we even have an interrupt, even more bad things could happen.
> 
> What is the reason you wrote this workaround?
The reason is simple, we've got this oops due to misrouted interrupts, 
misrouted_irq() function. This workaround helps us, please, advice how to  fix
it or fix it yourself.

> 
> Auke
> 
> > 
> > Signed-off-by: Dmitry Mishin <[email-masked]>
> > Signed-off-by: Pavel Emelianov <[email-masked]>
> > 
> > ---
> >  e1000_main.c |    9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > ---
> > --- ./drivers/net/e1000/e1000_main.c.e1000	2006-09-20 07:42:06.000000000 +0400
> > +++ ./drivers/net/e1000/e1000_main.c	2006-11-22 14:08:15.000000000 +0300
> > @@ -1206,14 +1206,15 @@ e1000_open(struct net_device *netdev)
> >  	if ((err = e1000_setup_all_rx_resources(adapter)))
> >  		goto err_setup_rx;
> >  
> > -	err = e1000_request_irq(adapter);
> > -	if (err)
> > -		goto err_up;
> > -
> >  	e1000_power_up_phy(adapter);
> >  
> >  	if ((err = e1000_up(adapter)))
> >  		goto err_up;
> > +
> > +	err = e1000_request_irq(adapter);
> > +	if (err)
> > +		goto err_up;
> > +
> >  	adapter->mng_vlan_id = E1000_MNG_VLAN_NONE;
> >  	if ((adapter->hw.mng_cookie.status &
> >  			  E1000_MNG_DHCP_COOKIE_STATUS_VLAN_SUPPORT)) {
> > -
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-- 
Thanks,
Dmitry.