From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jussi Haakana Date: Thu, 10 Mar 2011 08:16:42 +0200 Subject: [ath9k-devel] AR9280 with only one antenna? In-Reply-To: References: <4D775B17.7050809@7signal.com> <4D7769D3.7090605@7signal.com> <4D777AE9.3020704@7signal.com> Message-ID: <4D786CCA.7020508@7signal.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On 9.3.2011 18:04, Adrian Chadd wrote: > I didn't think the radiotap knew about MIMO. :) > > It's possible you're being told about the "old" antenna selection/information stuff. Hmm. I think that receiving antenna is set in ath9k_rx_skb_preprocess() (recv.c:984) to ieee80211_rx_status from which it is then copied to radiotap by mac80211? - Jussi > > > Adrian > > On 9 March 2011 23:14, Mohammed Shafi> wrote: > On Wed, Mar 9, 2011 at 6:34 PM, Jussi Haakana> wrote: >> On 9.3.2011 14:29, Mohammed Shafi wrote: >>> >>> On Wed, Mar 9, 2011 at 5:21 PM, Jussi Haakana> >>> wrote: >>>> >>>> On 9.3.2011 13:39, Mohammed Shafi wrote: >>>>> >>>>> On Wed, Mar 9, 2011 at 4:32 PM, Adrian Chadd> >>>>> wrote: >>>>>> >>>>>> >>>>>> I've found a couple places that hard-code setting up both chains (eg >>>>>> open-loop TX power control, which initialises it for both chains in the >>>>>> same >>>>>> location!) but that shouldn't matter. >>>>>> >>>>>> There's a function which sets the TX chainmask based on the >>>>>> sleep/btcoex >>>>>> mode, maybe you could try setting it to 0x1 there and see what happens. >>>>> >>>>> also hardcoding to 0x1 in the function of int >>>>> ath9k_hw_fill_cap_info(struct ath_hw *ah) >>>>> hw.c helps >>> >>> please add this before 2016, 2017 lines >>> >>> +pCap->tx_chainmask = 0x1; >>> +pCap->rx_chainmask =0x1; >>>>> >> >> I did that now the data stream seems to be going through antenna 0: >> >> 12:35:22.783976 599348659493us tsft 5240 MHz 11a 126dB signal antenna 0 [bit >> 14] CF +QoS DA:... >> 12:35:22.784021 599348659493us tsft 5240 MHz 11a 0dB signal antenna 0 [bit >> 14] CF +QoS DA:... >> 12:35:22.784064 599348660933us tsft 5240 MHz 11a -78dB signal antenna 0 [bit >> 14] CF +QoS DA:... >> 12:35:22.784109 599348660981us tsft 5240 MHz 11a -123dB signal antenna 0 >> [bit 14] CF +QoS DA:... >> 12:35:22.784153 599348660981us tsft 5240 MHz 11a 2dB signal antenna 0 [bit >> 14] CF +QoS DA:... >> >> However, I'm still receiving beacons through antenna 1: > > not much idea, probably we cannot change the rx mask i think. we can > only change the tx mask? > I heard this some senior eng saying this, but not sure. need to dig deep. > >> >> 12:35:23.781184 599349658003us tsft 6.0 Mb/s 5240 MHz 11a -54dB signal >> antenna 1 [bit 14] BSSID:... >> 12:35:23.985982 599349862803us tsft 6.0 Mb/s 5240 MHz 11a -75dB signal >> antenna 1 [bit 14] BSSID:... >> 12:35:24.190791 599350067603us tsft 6.0 Mb/s 5240 MHz 11a -75dB signal >> antenna 1 [bit 14] BSSID:... >> 12:35:24.298133 599350174394us tsft 6.0 Mb/s 5240 MHz 11a -76dB signal >> antenna 1 [bit 14] BSSID:... >> >> (btw, if you look at the signal levels on the topmost capture, they just >> look insane. Could the reason be my setup: one interface is in station mode >> transferring data, and other interface in monitor mode, watching the packet >> flow. Is it possible TX is interfering RX signal measurements?) >> >> - Jussi >> >> >>>>> >>>>> 2016 tx_chainmask = pCap->tx_chainmask; >>>>> 2017 rx_chainmask = pCap->rx_chainmask; >>>>> >>>> >>>> Ok, thanks, I'll try with these changes. >>>> >>>> - Jussi >>>> >>>>>> >>>>>> On 9 March 2011 18:48, Jussi Haakana> >>>>>> wrote: >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> I have a setup in which I can connect only one >>>>>>> antenna to AR9280 based card. Is there any way >>>>>>> to force ath9k to use this antenna only? I'm not >>>>>>> sure, but based on reported signal levels (tcpdump >>>>>>> on monitor interface), it looks like the card tries >>>>>>> to use both antennas even though there is only one >>>>>>> antenna connected. >>>>>>> >>>>>>> I've read from earlier posts that this could be >>>>>>> done by forcing rx/tx chainmasks to 1, does this >>>>>>> apply to current ath9k version (wireless-testing) >>>>>>> also? If I do this, does this have any side >>>>>>> effects? >>>>>>> >>>>>>> - Jussi >>>>>>> _______________________________________________ >>>>>>> ath9k-devel mailing list >>>>>>> ath9k-devel at lists.ath9k.org >>>>>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> ath9k-devel mailing list >>>>>> ath9k-devel at lists.ath9k.org >>>>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>>>> >>>>>> >>>> >>>> _______________________________________________ >>>> ath9k-devel mailing list >>>> ath9k-devel at lists.ath9k.org >>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>> >> >> > >