ath11k: QCN9074: low HE-MCS index

[Kalle Valo]

Tanguy Serrat <tanguy at squaremind.io> writes:

> Hi everyone,
>
> In my quest to get 2x QCN9074 paired and achieving high throughput
> data transfers, I am now facing issues with the AP configuration.
>
> Specifically, I cannot get more than HE-MCS 5 (AP and client 50cm
> apart) although SNR and RSSI are always very strong and supposedly in
> specs (SNR > 40db or RSSI < -48db).
>
> iw wlp6s0 link
> Connected to 00:15:61:27:cd:dc (on wlp6s0)
> SSID: Space
> freq: 5745
> RX: 1073584482 bytes (708567 packets)
> TX: 355824214 bytes (256143 packets)
> signal: -40 dBm
> rx bitrate: 1729.3 MBit/s 160MHz HE-MCS 4 HE-NSS 4 HE-GI 0 HE-DCM 0
> tx bitrate: 1729.3 MBit/s 160MHz HE-MCS 4 HE-NSS 4 HE-GI 0 HE-DCM 0
>
> In this case iperf3 shows ~950Mbits/s transfer speed. I am hoping to
> get at least twice as much.
>
> It seems to me that either mac80211, ath11k or hostapd are not
> advertising the available capabilities correctly. I have tried setting
> hostapd he_basic_mcs_set=65530 or others but did not help.
>
> I have added ieee80211_regdom=FR option to cfg80211 module on the AP
> side. Channel selection is done with ACS survey. I also tried other
> channels/frequencies without success eg. 5500Mhz.
>
> iw reg get
> global
> country FR: DFS-ETSI
> (2400 - 2483 @ 40), (N/A, 20), (N/A)
> (5150 - 5250 @ 80), (N/A, 23), (N/A), NO-OUTDOOR, AUTO-BW
> (5250 - 5350 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS, AUTO-BW
> (5470 - 5725 @ 160), (N/A, 26), (0 ms), DFS
> (5725 - 5875 @ 80), (N/A, 13), (N/A)
> (5945 - 6425 @ 160), (N/A, 23), (N/A), NO-OUTDOOR
> (57000 - 71000 @ 2160), (N/A, 40), (N/A)
>
> phy#0 (self-managed)
> country US: DFS-FCC
> (2402 - 2472 @ 40), (6, 30), (N/A)
> (5170 - 5250 @ 80), (N/A, 30), (N/A), AUTO-BW
> (5250 - 5330 @ 80), (N/A, 24), (0 ms), DFS, AUTO-BW
> (5490 - 5730 @ 160), (N/A, 24), (0 ms), DFS, AUTO-BW
> (5735 - 5895 @ 160), (N/A, 30), (N/A), AUTO-BW
> (5945 - 7125 @ 160), (N/A, 27), (N/A), NO-OUTDOOR, AUTO-BW
>
> Current setup is:
> - Intel x86
> - Ubuntu 22.04
> - Kernel built from ath 6.4.0-rc6-wt-ath+ (commit:
> c60d15f389ef9832a8da410e438d81b10327751f)
> with commit reverted from the bug ticket I opened
> (https://bugzilla.kernel.org/show_bug.cgi?id=217536).
> - 1x QCN9074 as AP, 1x as managed client 50cm apart
> - Both AP and Client are running with the latest 2.7.0 FW.
>
> I have started from this ticket
> (https://bugzilla.kernel.org/show_bug.cgi?id=217286) hostapd config
> file, and adapted, please find attached.
>
> Anyone seeing what could be my issue / how I could debug further ?

As a start please file this to bugzilla as a new bug. Always one issue
per report, please. Otherwise it's a nightmare to manage the bug
reports.

https://wireless.wiki.kernel.org/en/users/drivers/ath11k/bugreport

Try to provide as much as information as you can to the report. You said
that you have tested it 50 cm apart but have you tested it, for example,
3 m apart? Please also include your full kernel .config file and dmesg
output.

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