Erm in FreeBSD the non-qos data frames get a sequence number from the non-QoS "TID", which is TID 16 in FreeBSD. Are you sure mac80211 doesn't do seqno assignment at all for non-qos data frames? If so, maybe it should? adrian On 23 October 2012 07:11, Uwe Bergemann <mail@xxxxxxxxxxxxxxxxxx> wrote: > Hello everybody, > > this is my first post to this list and I hope to be right here > > I need to obtain the sequence numbers of (mainly, but not only qos/data) > frames that have been sent at mac80211 level (more precisely: at the > rate control module). > > Using a Hainan (AR5213A) I see different sequence numbers in the mac > header (socket buffer, skb) and on the air (using a sniffer running > wireshark). The hardware seems to use its own counters only. > > Two possible solutions to this problem come to my mind: > - if switching off h/w-assignment of seq nums is possible, do > everything in mac80211. > - read the h/w-assigned seq num from registers and write them into the > mac header, which is then returned to mac80211. > > Any advice on this topic is appreciated. > Thank you in advance > Uwe Bergemann > > > > So far I have looked around here: > > mainly from mac80211/tx.c: > - mac80211 claims that it can generate sequence numbers (seq num) only > for qos/data frames. > - It maintains one counter per STA and TID for this purpose and writes > the correct value into the mac header. > - All other frames are numbered by a global sequence counter ( delegated > to the driver by setting the IEEE80211_TX_CTL_ASSIGN_SEQ flag). > > so qos/data is handled by mac80211, all other is delegated to the > driver. > > ath5k/reset.c: > - On other h/w versions than AR5210, seq num and tsf counters are saved > over a reset. > - For mac revisions after Oahu (AR5211) only the global seq num counter > (0) exists, earlier revisions have 10 seq num counters (one per queue). > > I use a Hainan (AR5213A), thus having only one (global) counter, which > is perfectly ok for mac80211. > > from observations (wireshark sniffer): > - different qos classes are used, so I believe that different queues > are used. > - frames are numbered w/o regard to qos class, only the global counter > seems to be is used. > - sequence numbers are always assigned by hardware, not regarding if > IEEE80211_TX_CTL_ASSIGN_SEQ is set or not. > - the h/w assigned sequence number is not written to the mac header/skb. > After transmission, the mac80211 sequence numbers are printed if > tracing is switched on, not showing what was actually 'aired'. > > The problem seems to be kind of the opposite of >> > http://lists.freebsd.org/pipermail/freebsd-wireless/2011-August/000473.html > where no correct sequence numbers are set on beacon frames, since the > AR5416 in this case does not assign sequence numbers by itself. > > Later in this thread, Adrian Chadd describes how h/w seq num assignment > is switched off for the AR5416: >> AR5416: >> >> * D_MISC for each DCU, bit 20: Sequence number increment disable; resets to 0x0. >> * MAC_PCU_STA_ADDR_U16 - (0x8004) bit 29: REG_PRESERVE_SEQNUM: Stops >> PCU from replacing the sequence number >> >> AR5212: >> >> * D_MISC: same deal: bit 20 - SEQNUMINCDIS >> * same deal with MAC_PCU_STA_ADDR_U16 above: bit 29 >> >> 30 seconds with the HAL has shown what's going on: >> >> ar5416Reset(): >> >> /* >> * disable seq number generation in hw >> */ >> OS_REG_WRITE(ah, AR_STA_ID1, >> OS_REG_READ(ah, AR_STA_ID1) | AR_STA_ID1_PRESERVE_SEQNUM); >> >> That bit isn't set for the AR5212. >> >> Try disabling that, see if it works on the AR5416. > > To me this looks like h/w-controlled assignment of sequence numbers can > be switched off globally (on an AR5212), but I doubt this can be done > on a per-frame basis only for qos/data frames. All sequence numbers > then would have to be assigned by mac80211. > > > -- > 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 -- 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
