On Saturday 18 July 2009 23:19:36 Bob Copeland wrote: > On Sat, Jul 18, 2009 at 11:03 AM, Larry Finger<Larry.Finger@xxxxxxxxxxxx> wrote: > > Christian Lamparter wrote: > >> On Saturday 18 July 2009 03:05:04 Larry Finger wrote: > >>> Johannes and Christian, > >>> > >>> I am getting a WARN_ON from mac80211 in the location stated in the > >>> subject. I put in some test prints and got the following: > >>> > >>> sband->n_bitrates 8, Band 1, supp_rates 0x0 > >> hmm, so something decides to talk to a 5GHz network here? > >> But the AP doesn't have any available rates in that band!? > > > > Ah, band 1 is 5GHz, not 2.4. There are no 802.11a AP's in my neighborhood. > > > >> If my memory serves my right some people have triggered the same WARN_ON > >> with the ath5k driver as well... > >> unfortunately, I didn't follow the thread and now I can't find it anymore. > >> > >> (btw: is your b43 11a capable as well?) > > > > Yes it is, but that section is software crippled. > > > > Thanks for the patch. I'll let you know what happens. > > In the ath5k case as well, I'm willing to bet it has something to do with dual > band operation. IIRC at least some instances of this in the past were due to > getting the rate after the band was changed, e.g. due to scanning, and the peer > of course didn't support any rates on that band. > well, ieee80211_sta_monitor_work - which probes the AP every now and then - didn't check if we're scanning. The attached diff survives a non-stop scanning without throwing the WARN in rate_lowest_index once. However, I'm not so sure about the locking for hw_scanning and sw_scanning. It looks like only scan.c manipulates them under the scan mutex. But then, do we need locking for a single threaded workqueue? guess not. --- Larry, here's another _fix_ which might even fix the problem after all ;-) Regards, Chr --- diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 18dad22..4833e7c 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2210,6 +2210,9 @@ static void ieee80211_sta_monitor_work(struct work_struct *work) container_of(work, struct ieee80211_sub_if_data, u.mgd.monitor_work); + if (sdata->local->sw_scanning || sdata->local->hw_scanning) + return; + ieee80211_mgd_probe_ap(sdata, false); } -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
