On 24/02/2012 14:39, Johannes Berg wrote: > On Fri, 2012-02-24 at 14:34 +0100, Nicolas Cavallari wrote: >> On 23/02/2012 19:51, Nicolas Cavallari wrote: >>> On 23/02/2012 19:08, Christian Lamparter wrote: >>>> On Thursday, February 23, 2012 06:27:59 PM Nicolas Cavallari wrote: >>>>> On 23/02/2012 17:52, Christian Lamparter wrote: >>>>>> On Thursday, February 23, 2012 04:53:34 PM Nicolas Cavallari wrote: >>>>>>> While this seems to fix my problem, there could still be problems remaining >>>>>>> in this code path. Particularly carl9170_tx_status will do lots of things >>>>>>> like incrementing counters and waking up mac80211 queues... >>>>>> That should be alright. As a rule of thumb, for every call to >>>>>> carl9170_tx_accounting [called by carl9170_op_tx tx handler] >>>>>> we need to call carl9170_tx_status. If the station is still in >>>>>> ps mode, mac80211 will cache the station's frames and sets >>>>>> the TIM bits. >>>>> Part of the reason i wrote this, is because, while this patch fixes the >>>>> memory accounting problem and prevent the AP from stopping working, the >>>>> powersaving station sometimes cannot communicate with the AP anymore >>>>> (other stations can). The station uses ath9k, and is just really doing a >>>>> background scan. The first traces that i have just indicate that the >>>>> station entered powersave mode, then sends probe requests and probe >>>>> requests directed to the AP, then sends authentication requests to the >>>>> AP (?), but the AP does not respond to any of them... >>>>> >>>> Do you run an 802.11n ap on carl9170? >>> No, it's a 802.11g currently. >>> My current wild guess is that, the responses to those requests are >>> somehow still queued ... >> >> And i was right... >> >> /* >> * Ignore doze->wake transitions that are >> * indicated by non-data frames, the standard >> * is unclear here, but for example going to >> * PS mode and then scanning would cause a >> * doze->wake transition for the probe request, >> * and that is clearly undesirable. >> */ >> if (ieee80211_is_data(hdr->frame_control) && >> !ieee80211_has_pm(hdr->frame_control)) >> ap_sta_ps_end(sta); >> >> As (re)associations requests and Auth frames are not data frames, >> mac80211 still considers that the station is still in powersave mode, so >> it still queues frames, and even queues the responses to the auth >> frames. Except that the station disassociated silently, and is trying to >> re-associate after a short time. >> >> Shouldn't mac80211 transition the sta to "awake" when receiving >> auth/assoc frames ? > > I don't think so, that would make us send frames to the station it no > longer deserves to have. Hostapd should instead delete & re-create the > station entry, I think? > > johannes > Hostapd already does that¹ ... after the association response is acked. Will send a patch for hostapd then. [¹] : /* * Remove the STA entry in order to make sure the STA PS state gets * cleared and configuration gets updated in case of reassociation back * to the same AP. */ hostapd_drv_sta_remove(hapd, sta->addr); -- 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
