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

From: Auke Kok <[email-masked]>
Date: Wed, 22 Nov 2006 08:19:16 -0800

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?

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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