Re: [PATCH] usb-gadget-ether: Prevent oops caused by error interrupt race -V2 (comments update)

Thomas Gleixner
2007-09-22T19:30:49Z

On Sat, 2007-09-22 at 12:18 -0700, David Brownell wrote:
> I think you misread my comment. Those requests are **NOT** pending!!
> So this update has a *MORE* incorrect description of the issue.
>
> That's just the freelist ... it's a fairly conventional model whereby
> there's a pool of "free" request slots which can be issued. When the
> pool empties, the TX queue shuts down until one of the requests which
> is pending in the hardware completes, and makes a slot free.
>
> The problem you're addressing is that there's a small window where a
> disconnect IRQ can shut down the TX queue (and empty that freelist)
> after upper layers in the network stack started a transmission on
> an active (pre-disconnect) TX queue.
>
> That problem is *NOT* related to any pending requests at all!!

Sorry, I misunderstood your comment. Can you please add the correct
comment yourself before we play some more rounds of ping pong ?

tglx