Subject: Re: [PATCH 3/4] sfc: resolve tx multiqueue bug

From: Jeff Garzik <[email-masked]>
Date: Tue, 22 Jul 2008 17:29:59 -0400

David Miller wrote:
> From: Ben Hutchings <[email-masked]>
> Date: Tue, 22 Jul 2008 19:41:19 +0100
> 
>> So long as a queue is only woken in response to TX completions, the current
>> arrangement is fine.  However, sfc needs to tear down and restart hardware TX
>> queues as part of some reconfiguration, self-test and recovery code, and I
>> doubt it's the only such driver.
> 
> Mark the carrier off and packets will stop flowing to the driver.

Yep.

Though based on looking at a lot of existing driver code, I think this 
is sometimes unclear to driver writers -- when to manage carrier 
(netif_carrier_on/off) and when to manage queue flow 
(netif_queue_start/stop/wake).

	Jeff