Re: Bisected 3.9 regression for iwl4965 connection problem to 1672c0e3

Stanislaw Gruszka
2013-05-07T08:41:19Z

On Mon, May 06, 2013 at 05:44:06PM +0200, Johannes Berg wrote:
> On Mon, 2013-05-06 at 17:31 +0200, Johannes Berg wrote:
>
> > > But if so, I would also see
> > > the breakage on my setup, but I don't - it works quite well here.
> >
> > Are you testing on a passive channel? Try with a large beacon interval.
>
> I think most likely what happens is that it's on a passive channel, and
> the firmware drops the TX packet with a bad status. Before the patch,
> we'd just wait sitting on the channel for HZ/5 (200ms) before trying
> again, with the patch we immediately retransmit the packet, which will
> fail again and again until the firmware received a beacon.
>
> If you look at iwlwifi/dvm/, it has some passive_no_rx workaround for
> this, which I don't see in iwlegacy.

Can you explain why it is named passive_no_rx instead passive_no_tx ?

> I think the best way to solve this would be to do such a thing in
> iwlegacy as well, but until then and for stable maybe we should
> introduce another HW flag to restore the previous mac80211 behaviour?

I'm not sure if I like to add passive_no_rx to iwlegacy. Stopping queues
and waiting for beacon looks sticky, what happen if beacon will not be
received?

Perhaps I will just remove IEEE80211_HW_REPORTS_TX_ACK_STATUS from 4965,
it's simpler workaround ?

Stanislaw