VHT-NSS 2 reported for device with 1x1:1 antenna #230

michaeltandy · 2019-01-09T14:43:37Z

I have a ASUS USB-AC51 using the MediaTek MT7610U, which (AFAIK) is a abgn+ac device, with a 1x1:1 antenna configuration. The advertised maximum speed is 433 Mbps, consistent with supporting a single spatial stream (at 80MHz, VHT-MCS 9 VHT-NSS 1, short guard interval)

However, when I run wavemon it reports rx rate: 130.0 Mbit/s VHT-MCS 7 VHT-NSS 2 (exp: 30.5 MB/s) i.e. more than one spatial stream.

Is the report of NSS=2 correct, despite the 1x1:1 design? Or is the report than NSS=2 incorrect?

Thanks for taking the time to read my bug report, and apologies if this is the wrong forum for me to ask this!

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LorenzoBianconi · 2019-01-09T15:35:32Z

I have a ASUS USB-AC51 <https://wikidevi.com/wiki/ASUS_USB-AC51> using the MediaTek MT7610U, which (AFAIK) is a abgn+ac device, with a 1x1:1 antenna configuration. The advertised maximum speed is 433 Mbps, consistent with supporting a single spatial stream (at 80MHz, VHT-MCS 9 VHT-NSS 1, short guard interval) However, when I run wavemon it reports rx rate: 130.0 Mbit/s VHT-MCS 7 VHT-NSS 2 (exp: 30.5 MB/s) i.e. more than one spatial stream. Is the report of NSS=2 correct, despite the 1x1:1 design? Or is the report than NSS=2 incorrect?

Can you please provide a traffic trace using a monitor interface?

…

Thanks for taking the time to read my bug report, and apologies if this is the wrong forum for me to ask this! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#230>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCe5VVZQIWQLd3JK2hKYsdhbbKII2ks5vBgAagaJpZM4Z3nv2> .

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michaeltandy · 2019-01-09T18:09:40Z

I can try :)

Do you mean you want the type of capture I'd get by running tshark -i wlx107b44e70d1b -I -y IEEE802_11_RADIO -a duration:10 -w linklayer-a.pcapng on the problem device? Or do you mean I should try to capture on a different device while the problem device starts up? Or are you looking for a trace of USB traffic and I've misunderstood? :)

LorenzoBianconi · 2019-01-09T18:43:30Z

Please add a monitor interface and sniff traffic while using the sta one: $iw phy phy0 interface add mon0 type monitor $ifconfig mon0 up $tcpdump -i mon0 -s0 -w /tmp/trace.pcap (or wireshark)

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On Wed, 9 Jan 2019, 19:37 Michael Tandy ***@***.*** wrote: I can try :) Do you mean you want the type of capture I'd get by running tshark -i wlx107b44e70d1b -I -y IEEE802_11_RADIO -a duration:10 -w linklayer-a.pcapng on the problem device? Or do you mean I should try to capture on a different device while the problem device starts up? Or are you looking for a trace of USB traffic and I've misunderstood? :) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#230 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCTHasgSveNZ10De9lHRtV3STX47Oks5vBjb3gaJpZM4Z3nv2> .

michaeltandy · 2019-01-10T09:58:41Z

Sure thing, here's a capture with some traffic generated by iperf: monitor-interface-trace-during-iperf.pcapng.gz

I assume you'll be looking at this header:-

Radiotap Header v0, Length 36
    Header revision: 0
    Header pad: 0
    Header length: 36
    Present flags
    Flags: 0x00
    Channel frequency: 5280 [A 56]
    Channel flags: 0x0140, Orthogonal Frequency-Division Multiplexing (OFDM), 5 GHz spectrum
    Antenna signal: -62dBm
    RX flags: 0x0000
    VHT information
        Known VHT information: 0x400
            .... .... .... ...0 = STBC: Absent
            .... .... .... ..0. = TXOP_PS_NOT_ALLOWED: Absent
            .... .... .... .1.. = Guard interval: Present
            .... .... .... 0... = SGI Nsym disambiguation: Absent
            .... .... ...0 .... = LDPC extra OFDM symbol: Absent
            .... .... ..0. .... = Beamformed: Absent
            .... .... .1.. .... = Bandwidth: Present
            .... .... 0... .... = Group ID: Absent
            .... ...0 .... .... = Partial AID: Absent
        .... .1.. = Guard interval: short (1)
        Bandwidth: 20 MHz (0)
        User 0: MCS 7
            0111 .... = MCS index 0: 7 (64-QAM 5/6)
            .... 0010 = Spatial streams 0: 2
            .... ...0 = Coding 0: BCC (0)
            [Data Rate: 144.4 Mb/s]
    Antenna signal: 0dBm
    Antenna: 0

LorenzoBianconi · 2019-01-10T14:17:19Z

Sure thing, here's a capture with some traffic generated by iperf: monitor-interface-trace-during-iperf.pcapng.gz <https://github.com/openwrt/mt76/files/2744699/monitor-interface-trace-during-iperf.pcapng.gz> I assume you'll be looking at this header:- Radiotap Header v0, Length 36 Header revision: 0 Header pad: 0 Header length: 36 Present flags Flags: 0x00 Channel frequency: 5280 [A 56] Channel flags: 0x0140, Orthogonal Frequency-Division Multiplexing (OFDM), 5 GHz spectrum Antenna signal: -62dBm RX flags: 0x0000 VHT information Known VHT information: 0x400 .... .... .... ...0 = STBC: Absent .... .... .... ..0. = TXOP_PS_NOT_ALLOWED: Absent .... .... .... .1.. = Guard interval: Present .... .... .... 0... = SGI Nsym disambiguation: Absent .... .... ...0 .... = LDPC extra OFDM symbol: Absent .... .... ..0. .... = Beamformed: Absent .... .... .1.. .... = Bandwidth: Present .... .... 0... .... = Group ID: Absent .... ...0 .... .... = Partial AID: Absent .... .1.. = Guard interval: short (1) Bandwidth: 20 MHz (0) User 0: MCS 7 0111 .... = MCS index 0: 7 (64-QAM 5/6) .... 0010 = Spatial streams 0: 2 .... ...0 = Coding 0: BCC (0) [Data Rate: 144.4 Mb/s] Antenna signal: 0dBm Antenna: 0 — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#230 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCT0rWH9xrayHR0K0bBpLmUusdFARks5vBw7SgaJpZM4Z3nv2> .

Yes, thx . I will look into it later today. Regards, Lorenzo

…

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LorenzoBianconi · 2019-01-11T17:07:35Z

@michaeltandy : could you please try following commit?
LorenzoBianconi@1408354

michaeltandy · 2019-01-16T19:14:30Z

I applied this diff atop kernel v4.20, but wavemon still seems to report rx rate: 117.0 Mbit/s VHT-MCS 6 VHT-NSS 2 (exp: 30.5 MB/s)

LorenzoBianconi · 2019-01-16T19:31:59Z

First of all thx for testing :) Could you please try this repo https://github.com/LorenzoBianconi/wireless-drivers-next/tree/mt76_nss_limit?files=1? Felix did an important tx status fix. Moreover could you please provide a traffic trace (as you did before)?

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On Wed, 16 Jan 2019, 20:14 Michael Tandy ***@***.*** wrote: I applied this diff atop kernel v4.20, but wavemon still seems to report rx rate: 117.0 Mbit/s VHT-MCS 6 VHT-NSS 2 (exp: 30.5 MB/s) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#230 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCbJIb74cipjtXt-3FqMK43TYxWAHks5vD3oYgaJpZM4Z3nv2> .

michaeltandy · 2019-01-17T18:35:38Z

I tested with 70d181330b75 from wireless-drivers-next and wavemon reports rx rate: 117.0 Mbit/s VHT-MCS 6 VHT-NSS 2 (exp: 30.5 MB/s) - here's a sample of that data: monitor-interface-70d181330b75.pcapng.gz

VHT information
    Known VHT information: 0x400
    .... .0.. = Guard interval: long (0)
    Bandwidth: 20 MHz (0)
    User 0: MCS 5
        0101 .... = MCS index 0: 5 (64-QAM 2/3)
        .... 0010 = Spatial streams 0: 2
        .... ...0 = Coding 0: BCC (0)
        [Data Rate: 104.0 Mb/s]

I accidentally also tested with the master branch (209b43759d65) which makes wavemon report rx rate: 52.0 Mbit/s MCS 5 (exp: 26.1 MB/s) i.e. removing the NSS but also the VHT.

michaeltandy · 2019-01-17T18:38:07Z

Incidentally, when shutting down I get this on the console:

usb usb1: USB disconnect, device number 1
usb 1-1: USB disconnect, device number 2
usb 1-1.4: USB disconnect, device number 3
mt76x0u 1-1.4:1.0: TX DMA did not stop
mt76x0u 1-1.4:1.0: Warning: MAC TX did not stop!
mt76x0u 1-1.4:1.0: Warning: MAC RX did not stop!
mt76x0u 1-1.4:1.0: RX DMA did not stop
ci_hdrc ci_hdrc.1: USB bus 1 deregistered

Don't know if it's relevant? It's at shutdown, so probably not :)

LorenzoBianconi · 2019-01-17T18:46:28Z

I tested with 70d181330b75 from wireless-drivers-next and wavemon reports rx rate: 117.0 Mbit/s VHT-MCS 6 VHT-NSS 2 (exp: 30.5 MB/s) - here's a sample of that data: monitor-interface-70d181330b75.pcapng.gz <https://github.com/openwrt/mt76/files/2770103/monitor-interface-70d181330b75.pcapng.gz> VHT information Known VHT information: 0x400 .... .0.. = Guard interval: long (0) Bandwidth: 20 MHz (0) User 0: MCS 5 0101 .... = MCS index 0: 5 (64-QAM 2/3) .... 0010 = Spatial streams 0: 2 .... ...0 = Coding 0: BCC (0) [Data Rate: 104.0 Mb/s] I accidentally also tested with the master branch (209b43759d65) which makes wavemon report rx rate: 52.0 Mbit/s MCS 5 (exp: 26.1 MB/s) i.e. removing the NSS but also the VHT. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#230 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCS2tfIlrEWUQYNNq9Oe_0FTSfsPXks5vEMJ8gaJpZM4Z3nv2> .

Now I figured out you are talking about rx side, I was just looking at tx one. I will work on it, thx Regards, Lorenzo

…

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LorenzoBianconi · 2019-01-20T11:12:08Z

@michaeltandy : could you please try this commit? LorenzoBianconi/wireless-drivers-next@6110621

michaeltandy · 2019-01-24T09:45:37Z

With LorenzoBianconi/wireless-drivers-next@611062117f10

rx rate: 58.5 Mbit/s VHT-MCS 6 VHT-NSS 1 (exp: 30.5 MB/s),

Looks good 😀

LorenzoBianconi · 2019-01-24T09:46:50Z

Cool :) Could you please close the bug? Regards, Lorenzo

…

On Thu, Jan 24, 2019 at 10:45 AM Michael Tandy ***@***.***> wrote: With ***@***.*** <LorenzoBianconi/wireless-drivers-next@611062117f10> rx rate: 58.5 Mbit/s VHT-MCS 6 VHT-NSS 1 (exp: 30.5 MB/s), Looks good 😀 — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#230 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCdIr3nMINfOD0ZkgH9OcwVp9qWWwks5vGYDDgaJpZM4Z3nv2> .

-- UNIX is Sexy: who | grep -i blonde | talk; cd ~; wine; talk; touch; unzip; touch; strip; gasp; finger; gasp; mount; fsck; more; yes; gasp; umount; make clean; sleep

michaeltandy · 2019-01-24T09:49:03Z

Sure thing! And if there's any way I can buy you a beer, I'd be glad to :)

LorenzoBianconi · 2019-01-24T09:56:21Z

On Thu, Jan 24, 2019 at 10:49 AM Michael Tandy ***@***.***> wrote: Sure thing! And if there's any way I can buy you a beer, I'd be glad to :) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#230 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABwNCaG_ymUsrqux3hkqReRen_qZ73fNks5vGYGQgaJpZM4Z3nv2> .

Oh, thx :) -- UNIX is Sexy: who | grep -i blonde | talk; cd ~; wine; talk; touch; unzip; touch; strip; gasp; finger; gasp; mount; fsck; more; yes; gasp; umount; make clean; sleep

michaeltandy closed this as completed Jan 24, 2019

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VHT-NSS 2 reported for device with 1x1:1 antenna #230

VHT-NSS 2 reported for device with 1x1:1 antenna #230

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VHT-NSS 2 reported for device with 1x1:1 antenna #230

VHT-NSS 2 reported for device with 1x1:1 antenna #230

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