On Tue, Feb 24, 2015 at 4:59 PM, Krishna Chaitanya <chaitanya.m...@gmail.com> wrote: > On Tue, Feb 24, 2015 at 4:05 PM, Johannes Berg > <johan...@sipsolutions.net> wrote: >> On Tue, 2015-02-24 at 15:58 +0530, Krishna Chaitanya wrote: >> >>> STA (mac80211) connects to AP in VHT-80. >>> AP is reconfigured to 11n40 (stops beaconing for about 30secs and then >>> starts again). >>> STA loses connection (HW_CONN_TRACK), iee80211_connection_loss is called. >>> STA see's AP again and tries to connect, >> >> But this goes through the supplicant, right? You actually get a full >> connection loss (which I certainly would expect after 30 seconds) > > Our HW N/W lost event timeout is 5secs. > >>> but due to BW tracking in >>> mac80211 it doesn't connect. >>> >>> So i guess we are not resetting the tracking after losing connection. >> >> Right, some flag is not getting reset correctly I suppose. I thought we >> had pretty robust code for this, but I guess not. >> >> Easiest might be to print the flags and other state for during all >> connection attempts, and then compare >> * VHT connection >> * subsequent HT connection >> * HT connection after reloading the driver > Sure Johannes, will share the info.
Before you spend time on this, my tests are based on older kernel 3.10.36 but the code in this ares looks pretty much same (At least the parts i am working on :-) ). If time permits, i will try the same with latest kernel as well. Usecase1: When changing from VHT80-HT40. STA disconnect but sometimes unable to reconnect. I have digged in to this issue further, and observed that whenever issue happens the bss_list in the scan list is having old information even though we are doing a new scan as BSS info is not found (even without new scan it should have been flushed). Sometimes "iw wlan0 scan dump" shows empty/VHT info (which is old). So while doing assoc, cfg80211 gets the bss information from bss_list (get_ie(VHT)) and passes to mac80211, which has VHT but AP's beacon/probe resp/assoc resp is HT only causing the issue. Event multiple connection attempts doesn't resolve this, but if i do repeated scan's i am able to connect. Use case2: When changing from HT40-VHT80, the connection goes through but it still connected as HT40 (vht_ie from cfg80211 is returned null). Can you think of any reason why the bss_list is not updated cfg80211? Note: iwconfig and wpa_supplicant both show same behavior. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
