[RFC][PATCH] b43: do not try sending packets when ring can be full

[Michael Büsch]

On Sun, 12 Jun 2011 20:15:53 +0200
Rafał Miłecki <zajec5 at gmail.com> wrote:
> Well, as I said, we may be unable to transmit the first element of the
> queue, but 2nd/3rd/... may be for different ring (qos) (we can
> transmit).
> 
> Looping through the whole queue every time, just to find packets we
> may transmit, sounds surely as a bad idea.

I don't think so. It's not that this is an actual queue anyway. It just acts
as a buffer to queue up one or two packets in the small race window of
actually filling up the DMA rings and stopping the mac80211 queue.
(It also acts as a context dispatcher in the first place, though).

So the "looping through the queue" just means checking if one or two packets
can be transmitted now.