MT7922 crash after 23–24 hours of operation when upstream AP disconnects

Hi,

I am using the MT7922 Wi-Fi module in an OpenWrt 23.x environment and have encountered a reproducible crash after long-term operation in Station + Access Point (STA + AP) mode. Please suggest if there is a known fix for this STA + AP stability issue when the upstream AP disconnects after long uptime.

Summary of the issue

• Firmware used: WIFI_MT7922_patch_mcu_1_1_hdr.bin and WIFI_RAM_CODE_MT7922_1.bin (Feb 20 2024 and Sept 2025 versions both tested)
• Kernel/driver: OpenWrt 23.x (mt76 driver)
• Mode: Single radio (radio0) operating simultaneously as STA uplink and AP for local clients

Steps to reproduce

1. Configure radio0 as STA connecting to an upstream AP on channel (e.g. 161).

2. On the same radio, start AP mode with SSID “WR315B” on the same channel.

3. Let the system run continuously for more than 23–24 hours.

4. When the upstream AP disconnects (e.g. hotspot turned off or signal lost), the system outputs messages such as:

   phy0-sta0: Driver requested disconnection from AP 00:00:00:00:00:00
   mt7921e 0000:01:00.0: Message 00000010 (seq 8) timeout
   mt7921e 0000:01:00.0: Failed to get patch semaphore
   mt7921e 0000:01:00.0: chip reset failed
   

5. After this, the wireless interface (phy0) disappears; wifi reload, ‘/etc/init.d/network restart’, rmmod/modprobe, ‘reboot’ cannot recover it. The PCI bus show no module. Only a full hardware reboot restores the module.

Observation and analysis

• The failure appears after long-term operation (> 23 h) and is triggered by the STA disconnection event.
• Updating to the 2025-09 firmware does not solve the problem, suggesting a driver/firmware synchronization issue involving PCIe reset and MCU power state.
• Disabling power save (iw dev phy0-sta0 set power_save off) may delay the issue but does not prevent it.

Start with the mt7921e disconnect and reset path indicated by the reported timeout, failed patch semaphore, and chip reset messages. Reproduce the STA + AP setup on OpenWrt 23.x after long uptime, comparing the listed firmware versions and power-save setting; done means the interface recovers after the upstream AP disconnects without a hardware reboot.