On Fri, Jul 25, 2008 at 5:36 PM, Herton Ronaldo Krzesinski <herton@xxxxxxxxxxxxxxx> wrote: <snipped> > The patch didn't help, but I reached a set of commands where I'm always able > to reproduce the problem, I found out that is the order of commands that > makes the issue happen here: > > [1] /sbin/ip link set dev wlan0 down > [2] /sbin/ip link set dev wlan0 up > [3] /sbin/iwconfig wlan0 power on > [4] /sbin/iwconfig wlan0 essid any > [5] /sbin/iwconfig wlan0 power on > [6] /sbin/iwconfig wlan0 essid <my AP> > [7] /sbin/iwconfig wlan0 key open <my key> > > With these commands the interface doesn't associate with AP. > If I remove only command 3, I still can't associate. > If I remove only command 4, no problems. > If I remove only command 5, no problems. > > So it seems there is a bug when trying to do a "power on" after "essid <key>" > command, are you able to reproduce this too? - I have added linux-wireless back to CC:, since I have reproduced the problem you saw, exactly as you described. (you mean "power on after essid <any>" is problematic, I think) I have also had a look at the code and while I don't understand most of it, I thought maybe I have a guess of how adding power management wext hooks can break association. What the power management hooks + enabling power management does, is to buffer for up to STA_MAX_TX_BUFFER frames of certain types; also, if a iwconfig essid <any> is issued before iwconfig essid <some_ap>, the <any> result is cached for look-up, I think. so the 3 situations you out-lined are this: -use a lot of frames to find any APs, (power saving on, start buffering) send a small number of frames to associate with one among the known APs but these frames are buffered, so no association - (power saving on, start buffering), use a lot of frames to find any APs, a few more to associate to one. - (power saving on, start buffering), doesn't know any APs, so use a lot of frames to find a particular one. Does this make sense, or am I talking nonsense? In any case, there is a MAC80211_VERBOSE_PS_DEBUG in net/mac80211/tx.c, which should be relevant. Hin-Tak -- 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
