wcn6855 2.1 - slow download speed on any pairwise cipher except CCMP

[Jeff Johnson]

On 3/31/2024 8:49 AM, Yaroslav Isakov wrote:
> Hello! When I tried to switch my OpenWRT router from default CCMP
> pairwise cipher to any other, supported by both my router (Asus
> TUF-AX6000) and my laptop (Thinkpat T14 Gen 4 AMD with WCN6855 2.1), I
> saw that download dropped from 1Gbit/s to 100 MBit/s. When I changed
> back to CCMP, download speed recovered back to 1Gbit/s. Upload speed
> is good, though, for all ciphers - 1Gbit/s.
> 
> Initially, I thought, that issue with either router hardware, or
> openwrt driver - but, I tested the same settings on another laptop -
> T14 Gen3 Intel - and with Intel WIFI, both download and upload speed
> was 1Gbit/s on any pairwise cipher.
> 
> This issue is 100% reproducible for me, it happens all the times I'm
> switching to any pairwise cipher other than CCMP.
> 
> I'm on Linux 6.7.6, compiled from sources on Gentoo.
> 
> Here is my dmesg for ath11k:
> [   13.092519] ath11k_pci 0000:02:00.0: BAR 0: assigned [mem
> 0x78600000-0x787fffff 64bit]
> [   13.093400] ath11k_pci 0000:02:00.0: enabling device (0000 -> 0002)
> [   13.095723] ath11k_pci 0000:02:00.0: MSI vectors: 32
> [   13.096260] ath11k_pci 0000:02:00.0: wcn6855 hw2.1
> [   13.974707] ath11k_pci 0000:02:00.0: chip_id 0x12 chip_family 0xb
> board_id 0xff soc_id 0x400c1211
> [   13.974732] ath11k_pci 0000:02:00.0: fw_version 0x1106196e
> fw_build_timestamp 2024-01-12 11:30 fw_build_id
> WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37
> [   14.315774] ath11k_pci 0000:02:00.0: Failed to set the requested
> Country regulatory setting
> [   14.316046] ath11k_pci 0000:02:00.0: Failed to set the requested
> Country regulatory setting
> [  337.889222] ath11k_pci 0000:02:00.0: failed to enqueue rx buf: -28
> 

There was another reporting of that error in this thread:
https://lore.kernel.org/all/5c63a3a2-29fe-444c-96f1-f87c89d7af39@gmail.com/

+Baochen Qiang for awareness

/jeff