[BUG] rtw89: high latency jitter on AzureWave Device 6110 (RTL8851BE) under Linux 6.14.4

["zhengyushi(ZHENGYU SHI)" <zhengyushi@xxxxxxxxxxxxxxxxxx>]

I’m seeing severe ping spikes (1?90 ms) when using the onboard Realtek RTL8851BE Wi-Fi (Device b851, rtw89_8851be) on Arch Linux. Switching to a USB-tethered phone (same AP) completely eliminates the jitter (<5 ms). The behavior is completely reproducible. I suspect an issue in the rtw89 driver’s power-management or PCIe handling.

I tried
- Disabling power management via injecting ASPM/L1/L1SS and CLKREQ via rtw89_pci.disable_clkreq=y rtw89_pci.disable_aspm_l1=y rtw89_pci.disable_aspm_l1ss=y
- Verified no firmware?driven roaming or reassociation in logs

Device Info:
% lspci | awk '/[Nn]et/ {print $1}' | xargs -i% lspci -ks %
07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet Controller (rev 15)
	DeviceName: Realtek RTL8125BG LAN
	Subsystem: ASUSTeK Computer Inc. Onboard RTL8111H Ethernet
	Kernel driver in use: r8169
	Kernel modules: r8169
08:00.0 Network controller: Realtek Semiconductor Co., Ltd. Device b851
	Subsystem: AzureWave Device 6110
	Kernel driver in use: rtw89_8851be
	Kernel modules: rtw89_8851be

% uname -r
6.14.4-arch1-1

% mtr 8.8.8.8
Apotheosis (192.168.0.42) → 8.8.8.8 (8.8.8.8)  2025-05-05T21:15:47+0800
 Host                    Loss%  Snt  Last   Avg  Best  Wrst  StDev
 1. _gateway              0.3%   330   0.7   1.6   0.3  82.4   5.8
 2. 100.66.0.3            1.2%   330   2.0   3.1   1.2 109.9   9.5
 3. chj-dsl9.vqbn.com     0.3%   330   2.0   3.3   1.3  95.3   8.5
 4. 132.147.112.109       0.0%   329   2.6   4.0   1.7 102.8   9.4
 5. 132.147.112.194      24.0%   329   4.7   7.9   3.4 127.1  16.0
 6. 209.85.255.97         0.0%   329   2.5   3.5   1.6 131.1   8.6
 7. 142.251.241.1         0.0%   329   2.4   3.4   2.0 109.7   7.3
 8. dns.google            0.0%   329   2.8   3.0   1.5 105.9   7.2

journalctl shows no roaming or disassociation
May 05 23:41:34 Apotheosis kernel: wlp8s0: associate with 74:05:a5:75:20:c7 (try 1/3)
May 05 23:41:34 Apotheosis kernel: wlp8s0: associated

―
Could someone advise whether this is a known issue in the rtw89 driver? Are there additional debug stuff I should test? Happy to provide more logs if needed.

Thanks in advance for any guidance.

―
Zhengyu Shi
ethernet/PCI IDs: Realtek RTL8851BE (b851) on AzureWave 6110
Arch Linux 6.14.4-arch1-1
Email: zhengyushi@xxxxxxxxxxxxxxxxxx