Re: RFR: new SiS gige driver

Jeff Garzik wrote:

Andi Kleen wrote:

quoted

* netif_stop_queue in hard_start_xmit is not protected against the 
interrupt by the spinlock. That's racy, isn't it?

Shouldn't be, if done right.  If the interrupt runs a TX completion 
cycle, it will run the code
    if (work_done && netif_queue_stopped(dev))
        netif_wake_queue(dev)

Since ->hard_start_xmit is guaranteed never to be called if the queue is 
stopped, you also guaranteed that netif_wake_queue and ->hard_start_xmit 
are mutually exclusive.

Is this really guaranteed?  What if the queue is stopped between the check
to see if it's stopped and the call to hard_start_xmit?

Ben


-- 
Ben Greear [off-list ref]
Candela Technologies Inc  http://www.candelatech.com