wcn7850 issues

david Atkins david at 3adesign.co.uk
Mon Aug 19 03:55:21 PDT 2024


> On 8/16/2024 8:23 PM, david Atkins wrote:
> >> On 8/15/2024 4:38 AM, david Atkins wrote:
> >>>>
> >>>> On 8/6/2024 4:06 PM, david Atkins wrote:
> >>>>> No support for EHT and therefore no MSC 12 or 13 which fits with
> >>>>> the dmesg warning about it not being supported,
> >>>> did not noted this ... So if AP does not support EHT, above
> >>>> warnings makes sense, like you said.
> >>>>
> >>>
> >>> Anseres inline, AP supports EHT
> >>>
> >>>> is this a card firmware
> >>>>> issue rather than the driver?
> >>>> did not follow you here, why is it an issue?
> >>>>
> >>>
> >>> Is the firmware that’s uploaded to the card not supporting EHT?
> >>>
> >> FW does support EHT.
> >>
> >> You are checking scan results, so it is AP not advertising EHT
> >> support (actually AP supports EHT, it is missing in scan results
> >> because IW does not print it. I don't know your IW, but at least
> >> upstream IW does not print it currently), not WCN7850.
> >
> >
> > I have captured beacon packets from the AP, they show the presence of EHT,
> this is a snip from the packet decoded, is there something here that would
> prevent the Hamilton card seeing eht?
> >
> >         Ext Tag: EHT Capabilities (802.11be D3.0)
> >             Ext Tag length: 14 (Tag len: 15)
> >             Ext Tag Number: EHT Capabilities (802.11be D3.0) (108)
> >             EHT MAC Capabilities Information: 0x0017, EPCS Priority Access
> Support, EHT OM Control Support, Triggered TXOP Sharing Mode 1 Support,
> Restricted TWT Support, Maximum MPDU Length: 3 895, EHT Link Adaptation
> Support: No feedback
> >                 .... .... .... ...1 = EPCS Priority Access Support: Supported
> >                 .... .... .... ..1. = EHT OM Control Support: Supported
> >                 .... .... .... .1.. = Triggered TXOP Sharing Mode 1 Support: Supported
> >                 .... .... .... 0... = Triggered TXOP Sharing Mode 2 Support: Not
> supported
> >                 .... .... ...1 .... = Restricted TWT Support: Supported
> >                 .... .... ..0. .... = SCS Traffic Description Support: Not supported
> >                 .... .... 00.. .... = Maximum MPDU Length: 3 895 (0x0)
> >                 .... ...0 .... .... = Maximum A-MPDU Length Exponent Extension: 0
> >                 .... ..0. .... .... = EHT TRS Support: Not supported
> >                 .... .0.. .... .... = TXOP Return Support In TXOP Sharing Mode 2: Not
> supported
> >                 .... 0... .... .... = Two BQRs Support: Not supported
> >                 ..00 .... .... .... = EHT Link Adaptation Support: No feedback (0)
> >                 00.. .... .... .... = Reserved: 0x0
> >             EHT PHY Capabilities Information
> >                 EHT PHY Bits 0-15: 0xffe0
> >                     .... .... .... ...0 = Reserved: 0x0
> >                     .... .... .... ..0. = Support For 320 MHz in 6 GHz: Not supported
> >                     .... .... .... .0.. = Support for 242-tone RU in BW Wider than 20
> MHz: Not supported
> >                     .... .... .... 0... = NDP With 4x EHT-LTF And 3.2 us GI: Not
> supported
> >                     .... .... ...0 .... = Partial Bandwidth UL MU-MIMO: Not supported
> >                     .... .... ..1. .... = SU Beamformer: Supported
> >                     .... .... .1.. .... = SU Beamformee: Supported
> >                     .... ..11 1... .... = Beamformee SS (<= 80 MHz): 0x7
> >                     ...1 11.. .... .... = Beamformee SS (= 160 MHz): 0x7
> >                     111. .... .... .... = Beamformee SS (= 320 MHz): 0x7
> >                 EHT PHY Bits 16-31: 0x00db
> >                     .... .... .... .011 = Number Of Sounding Dimensions (<= 80 MHz):
> 0x3
> >                     .... .... ..01 1... = Number Of Sounding Dimensions (= 160 MHz):
> 0x3
> >                     .... ...0 11.. .... = Number Of Sounding Dimensions (= 320 MHz):
> 0x3
> >                     .... ..0. .... .... = Ng = 16 SU Feedback: Not supported
> >                     .... .0.. .... .... = Ng = 16 MU Feedback: Not supported
> >                     .... 0... .... .... = Codebook Size = (4,2) SU Feedback: Not
> supported
> >                     ...0 .... .... .... = Codebook Size = (7,5) MU Feedback: Not
> supported
> >                     ..0. .... .... .... = Triggered SU Beamforming Feedback: Not
> supported
> >                     .0.. .... .... .... = Triggered MU Beamforming Partial BW Feedback:
> Not supported
> >                     0... .... .... .... = Triggered CQI Feedback: Not supported
> >                 EHT PHY Bits 32-39: 0x18
> >                     .... ...0 = Partial Bandwidth DL MU-MIMO: Not supported
> >                     .... ..0. = EHT PSR-Based SR support: Not supported
> >                     .... .0.. = Power Boost Factor Support: Not supported
> >                     .... 1... = EHT MU PPDU With 4x EHT-LTF and 0.8 us GI:
> Supported
> >                     0001 .... = Max Nc: 1
> >                 EHT PHY Bits 40-63: 0x3ed876
> >                     .... .... .... .... .... ...0 = Non-Triggered CQI Feedback: Not
> supported
> >                     .... .... .... .... .... ..1. = Tx 1024-QAM & 4096-QAM < 242-tone RU
> Support: Supported
> >                     .... .... .... .... .... .1.. = Rx 1024-QAM & 4096-QAM < 242-tone-RU
> Support: Supported
> >                     .... .... .... .... .... 0... = PPE Thresholds Present: Not Present
> >                     .... .... .... .... ..11 .... = Common Nominal Packet Padding: 3
> >                     .... .... .... .000 01.. .... = Maximum Number Of Supported EHT-
> LTFs: 1
> >                     .... .... .101 1... .... .... = Support Of MCS 15: 11
> >                     .... .... 1... .... .... .... = Support Of EHT DUP (MCS 14) in 6 GHz:
> Supported
> >                     .... ...0 .... .... .... .... = Support For 20 MHz Operating STA
> Receiving NDP With Wider BW: Not supported
> >                     .... ..1. .... .... .... .... = Non-OFDMA UL MU-MIMO (BW <= 80
> MHz): Supported
> >                     .... .1.. .... .... .... .... = Non-OFDMA UL MU-MIMO (BW = 160
> MHz): Supported
> >                     .... 1... .... .... .... .... = Non-OFDMA UL MU-MIMO (BW = 320
> MHz): Supported
> >                     ...1 .... .... .... .... .... = MU Beamformer (BW <= 80 MHz):
> Supported
> >                     ..1. .... .... .... .... .... = MU Beamformer (BW = 160 MHz):
> Supported
> >                     .0.. .... .... .... .... .... = MU Beamformer (BW = 320 MHz): Not
> supported
> >                     0... .... .... .... .... .... = TB Sounding Feedback Rate Limit: Not
> supported
> >                 EHT PHY Bits 64-71: 0x444400
> >                     .... ...0 = Rx 1024-QAM In Wider Bandwidth DL OFDMA Support:
> Not supported
> >                     .... ..0. = Rx 4096-QAM In Wider Bandwidth DL OFDMA SUpport:
> Not supported
> >                     0000 00.. = Reserved: 0x00
> >             Supported EHT-MCS and NSS Set
> >                 EHT-MCS Map (BW <= 80MHz): 0x444444
> >                     .... .... .... .... .... 0100 = Rx Max Nss That Supports EHT-MCS 0-9:
> 4
> >                     .... .... .... .... 0100 .... = Tx Max Nss That Supports EHT-MCS 0-9: 4
> >                     .... .... .... 0100 .... .... = Rx Max Nss That Supports EHT-MCS 10-
> 11: 4
> >                     .... .... 0100 .... .... .... = Tx Max Nss That Supports EHT-MCS 10-
> 11: 4
> >                     .... 0100 .... .... .... .... = Rx Max Nss That Supports EHT-MCS 12-
> 13: 4
> >                     0100 .... .... .... .... .... = Tx Max Nss That Supports EHT-MCS 12-
> 13: 4
> >         Ext Tag: EHT Operation (802.11be D3.0)
> >             Ext Tag length: 8 (Tag len: 9)
> >             Ext Tag Number: EHT Operation (802.11be D3.0) (106)
> >             EHT Operation Parameters: 0x01, EHT Operation Information Present
> >                 .... ...1 = EHT Operation Information Present: True
> >                 .... ..0. = Disabled Subchannel Bitmap Present: False
> >                 .... .0.. = EHT Default PE Duration: False
> >                 .... 0... = Group Addressed BU Indication Limit: False
> >                 ..00 .... = Group Addressed BU Indication Exponent: 0
> >                 00.. .... = Reserved: 0x0
> >             Basic EHT-MCS And Nss Set: 0x44444444
> this means AP requires STA NSS to be equal or larger than 4, however
> WCN7850 only support 2, so connection in EHT is rejected.
>

The MCS Rx/Tx Max re maximum from my reading of the spec, not minimum's, the driver work out the max it supports in this case 2 and this less than 4 so it should work.
 
> >             Control: 0x02, Channel Width: 80 MHz EHT BSS bandwidth
> >                 .... .010 = Channel Width: 80 MHz EHT BSS bandwidth (2)
> >                 0000 0... = Reserved: 0x00
> >             CCFS0: 0x0000006a
> >             CCFS1: 0x00000000
> >
> >


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