qualcommax/ipq50xx: Redmi AX5400 ath11k has no NSS Wi-Fi offload support, Wi-Fi throughput much lower than PHY rate

Describe the bug

On a Xiaomi Redmi AX5400 (qualcommax/ipq50xx, IPQ5018 + QCN9074), 5 GHz Wi-Fi associates correctly at Wi-Fi 6 HE80 rates, but actual Wi-Fi throughput is much lower than expected. Runtime inspection shows that the ath11k module has no nss_offload parameter, so NSS Wi-Fi offload support is not compiled in.

This looks like a missing feature / acceleration path for ath11k on qualcommax/ipq50xx, rather than a normal wireless configuration issue. Wired throughput is normal, and the station PHY rate is high.

I reproduced this on an ImmortalWrt master build, but I am filing here because the relevant target/driver stack is inherited from OpenWrt qualcommax/ipq50xx. If this should be tracked only downstream, please let me know.

Hardware

• Device: Xiaomi Redmi AX5400 / Redmi AX5400
• Target: qualcommax/ipq50xx
• SoC / radios: IPQ5018 + QCN6024/QCN9024/QCN9074 class ath11k radio
• Client tested: Wi-Fi 6 2x2 client, connected to 5 GHz SSID

Firmware / build

• Source tree used: ImmortalWrt master
• Commit tested: f95f557d0478458d07b091007411895b22d7522d
• Kernel on router: Linux cola 6.12.92 #0 SMP Fri Jun 12 03:56:12 2026 aarch64 GNU/Linux

Wireless configuration tested

5 GHz was configured to a stable non-DFS HE80 channel:

wireless.radio1.type='mac80211'
wireless.radio1.band='5g'
wireless.radio1.channel='36'
wireless.radio1.htmode='HE80'
wireless.radio1.country='US'
wireless.radio1.disabled='0'

Firewall offload was also tested with software flow offload enabled and hardware flow offload disabled:

firewall.@defaults[0].flow_offloading='1'
firewall.@defaults[0].flow_offloading_hw='0'

Observed behavior

The client associates at a high PHY rate, for example:

Station 14:ac:60:b3:97:d1 (on phy1-ap0)
  signal: -66 dBm
  tx bitrate: 1080.6 MBit/s 80MHz HE-MCS 10 HE-NSS 2
  rx bitrate: 1200.9 MBit/s 80MHz HE-MCS 11 HE-NSS 2
  expected throughput: 887.703Mbps

However, practical Wi-Fi throughput is only around 300-500 Mbit/s in iperf3/speed tests, while wired networking is normal.

NSS / module inspection

ath11k does not expose the NSS offload parameter:

cat /sys/module/ath11k/parameters/nss_offload
# missing / no such parameter

Loaded modules only show qca_nss_dp, not the full NSS Wi-Fi acceleration stack:

ath11k                475136  2 ath11k_pci,ath11k_ahb
ath11k_ahb             24576  0
ath11k_pci             20480  0
cfg80211              364544  2 ath11k,mac80211
mac80211              700416  1 ath11k
qca_nss_dp             40960  0
qca_ssdk              516096  1 qca_nss_dp

There is no qca-nss-drv, qca-nss-ecm, SFE/shortcut-fe, or ath11k NSS Wi-Fi offload path loaded.

Source inspection

In the tested tree, qualcommax/ipq50xx includes kmod-qca-nss-dp, but I could not find the full NSS Wi-Fi offload integration for ath11k, such as:

• ATH11K_NSS_SUPPORT
• MAC80211_NSS_SUPPORT
• qca-nss-drv
• qca-nss-ecm
• ath11k NSS patches providing nss_offload=1

For comparison, external NSS-focused trees have ath11k NSS patches and nss_offload support, but they do not appear to provide a complete current OpenWrt qualcommax/ipq50xx / Redmi AX5400 integration.

Expected behavior

For a 2x2 HE80 client associated at ~1201 Mbit/s PHY, Wi-Fi throughput should be much closer to the reported expected throughput and should not be limited to roughly 300-500 Mbit/s by the CPU/mac80211 datapath if NSS Wi-Fi offload is intended to be supported on this target.

Question

Is NSS Wi-Fi offload for ath11k on qualcommax/ipq50xx / IPQ5018 + QCN9074 expected to be supported upstream? If not, would adding qca-nss-drv/qca-nss-ecm plus ath11k NSS offload patches for this target be acceptable, or is this outside OpenWrt upstream scope?

Review the qualcommax/ipq50xx target package definitions and the ath11k build and patch integration, then compare the tested tree with the external NSS-focused trees mentioned in the report. Check whether ATH11K_NSS_SUPPORT, MAC80211_NSS_SUPPORT, qca-nss-drv, qca-nss-ecm, and the nss_offload parameter are supported for this target. Done means establishing upstream scope and a complete, tested offload path if it is accepted.