【ZhangFengQianCheng-dev】 在 https://github.com/istoreos/istoreos/issues/2679 发布：
Hello iStoreOS Team,
I am reporting a critical bug that prevents the new MediaTek MT7925 (Wi-Fi 7) card from operating at 160MHz bandwidth when used in AP mode. The interface fails to initialize whenever a DFS channel is required, which effectively makes the card’s high-performance capabilities unusable.
This appears to be a systemic, upstream issue related to the mt76 driver’s DFS handling in AP mode.
- System Environment
Platform: x86_64
Device: GMKtec M5 PLUS
CPU: AMD Ryzen 7 5825U
Wireless Card: MediaTek MT7925 (Wi-Fi 7)
OS Version: iStoreOS 24.10.2-2025082211
Kernel Version: Linux 6.6.93
- Problem Description & Steps to Reproduce
Goal: To run the MT7925 card as an access point with 160MHz channel width.
Steps:
Navigate to the Network > Wireless page.
Edit the 5GHz radio device (radio0).
Set Channel Bandwidth to 160MHz.
Set Channel to 36 (or any other channel that requires a 160MHz-wide DFS block).
Click “Save & Apply”.
Expected Result:
The wireless interface should start successfully, and the SSID should be broadcast, allowing clients to connect at 160MHz.
Actual Result:
The wireless interface (phy0-ap0) fails to initialize. No SSID is broadcast, and the interface remains down. The system log shows a fatal error during the DFS check.
- Key Log Evidence (The “Smoking Gun”)
The following critical error sequence was captured from logread at the moment the configuration was applied. It clearly shows the point of failure:
daemon.notice hostapd: phy0-ap0: interface state HT_SCAN->DFS
daemon.notice hostapd: phy0-ap0: DFS-CAC-START freq=5180 chan=36 sec_chan=1, width=2, seg0=50, seg1=0, cac_time=60s
daemon.err hostapd: DFS start_dfs_cac() failed, -1
daemon.err hostapd: Interface initialization failed
daemon.notice hostapd: phy0-ap0: interface state DFS->DISABLED
daemon.notice hostapd: phy0-ap0: AP-DISABLED
The key message is DFS start_dfs_cac() failed, -1. This indicates a failure at a very low level when hostapd requests the kernel/driver to perform the Channel Availability Check.
- Analysis & Troubleshooting Steps Taken
Hardware and Firmware Confirmed Working: The dmesg log confirms that the MT7925 card and its firmware are correctly identified and loaded at boot.
IGNORE_WHEN_COPYING_START
IGNORE_WHEN_COPYING_END
mt7925e 0000:03:00.0: HW/SW Version: 0x8a108a10, Build Time: 20231227093012a
mt7925e 0000:03:00.0: WM Firmware Version: ____000000, Build Time: 20231227093232
Non-DFS Mode Works Perfectly: The card works flawlessly when configured to 80MHz bandwidth on a non-DFS channel (e.g., channel 149). This proves the hardware itself is not faulty and that the issue is specific to the DFS implementation.
Client Compatibility Confirmed: The client device used for testing (iQOO Z9 Turbo+) fully supports Wi-Fi 7 and 160MHz bandwidth.
- Corroborating Evidence: This is a Known Upstream Issue
This is not an isolated incident. The exact same bug has been reported in other OpenWrt-based communities, indicating the problem lies in the upstream mt76 driver or its integration with hostapd.
Similar Issue on openwrt/mt76 repository:
Title: DFS support on MT7925E #926
Description: A user with an MT7925E card reports the identical DFS start_dfs_cac() failed, -1 error on both OpenWrt Stable and Snapshot builds.
Similar Issue on immortalwrt/immortalwrt repository:
Title: mediatek/filogic 将5G WiFi设置为160MHz，WiFi消失 #1681
Description: Users with ARM-based Filogic devices (like the H3C NX30 Pro) report the same symptom. This issue was closed as “not planned,” suggesting the fix is complex and depends on upstream (likely MediaTek or the mainline kernel developers).
Conclusion
The evidence strongly suggests this is a software bug within the current mt76 driver and/or hostapd package when handling DFS operations for the new generation of MediaTek Wi-Fi 7 chipsets. The fix is likely beyond user configuration and requires a patch at the driver or system software level.
Could the iStoreOS team please investigate this issue or track the upstream progress for a fix? Enabling 160MHz is critical for leveraging the full potential of this modern hardware.
Thank you for your excellent work on iStoreOS. Please let me know if you need any further logs or testing from my side.