[Question] mt7925: CSI (Channel State Information) support in STA firmware?

[Geramy Loveless]

Sorry for the duplicate email I didnt realize there was a mailing list
for mediatek i got the last mailing list wrong also which created
another duplicate sorry, anyways to my problem.

I'm working on enabling CSI extraction on the MT7925 (Filogic 360,
PCIe) running as a station. I've built the full kernel-side
infrastructure (vendor netlink, ring buffer, debugfs, event handlers)
and have been testing against the stock firmware:

  WIFI_RAM_CODE_MT7925_1_1.bin
  Version: t-neptune-main-mt7925-2249 (build 2025-12-10)

I found the connac3 CSI patch for mt7996 in the MediaTek SDK feeds:

  0095-mtk-mt76-mt7996-Add-connac3-csi-feature.patch
  (by Chank Chen, Jan 2024)

which defines:

  MCU_UNI_CMD_CSI_CTRL  = 0x4A
  MCU_UNI_EVENT_CSI_REPORT = 0x4A

  Command tags:
    UNI_CMD_CSI_STOP          = 0
    UNI_CMD_CSI_START         = 1
    UNI_CMD_CSI_SET_FRAME_TYPE = 2
    ...

I've been sending MCU_WM_UNI_CMD(CSI_CTRL) with tag=1 (CSI_START) to
the MT7925 firmware. The command returns success (ret=0) but the
firmware never generates MCU_UNI_EVENT_CSI_REPORT (eid=0x4A) events.

All commands return success but none produce CSI I/Q data events.

My questions:

  1. Does the MT7925 STA firmware (CE variant) have the CSI reporting
     handler compiled in? Or is CSI only available in AP firmware
     builds (mt7996, mt7981)?

  2. If CSI is not in the current firmware, is there a firmware build
     or roadmap that would add MCU_UNI_CMD_CSI_CTRL support for the
     MT7925 in STA mode?

  3. Is there any alternative path to obtain per-subcarrier channel
     estimates on the MT7925? (e.g., via ICAP, WiFi Spectrum mode,
     or PHY register reads)

The kernel-side driver patches are ready and tested. The full
infrastructure (NL80211 vendor commands, TLV event parsing, ring
buffer) will work immediately once the firmware starts delivering
CSI events.

Hardware: ASUS ROG Strix Halo (Ryzen AI Max+ 395)
WiFi: MT7925 PCIe [14c3:7925]
Kernel: 7.0-rc7 with mt76 from mainline + CSI patches
Firmware: WIFI_RAM_CODE_MT7925_1_1.bin v2249

Thanks for any guidance.

Geramy Loveless