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Anthony96922 / mt7601u-ap

AP driver for MT7601U dongles
GNU General Public License v2.0
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Device not registering #27

Closed jschultz closed 3 years ago

jschultz commented 3 years ago

Hello,

If you can offer any help here I'd be really grateful.

I built the module on a Raspberry Pi model B running kernel 5.10.17 But it doesn't register my device. The stock module mt7601u does register the device no problems.

One possible clue that I found in dmesg:

rt2870: probe of 1-1.2:1.0 failed with error -1

Output from lsusb:

Bus 001 Device 006: ID 2341:0043 Arduino SA Uno R3 (CDC ACM)
Bus 001 Device 005: ID 148f:7601 Ralink Technology, Corp. MT7601U Wireless Adapter
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. SMC9512/9514 USB Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

[UPDATE] Although the probe error above seemed to be connected with a different device, a closer look at the top of dmesg reveals that it is in fact related to the mt7601u device (1-1.2):

[    6.121345] usb 1-1.2: new high-speed USB device number 4 using dwc_otg
[    6.273168] usb 1-1.2: New USB device found, idVendor=148f, idProduct=7601, bcdDevice= 0.00
[    6.288240] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    6.299235] usb 1-1.2: Product: 802.11 n WLAN
[    6.307132] usb 1-1.2: Manufacturer: MediaTek
[    6.314931] usb 1-1.2: SerialNumber: 1.0

Something about the cheap USB Wifi adapter that causes the probe to fail?

jschultz commented 3 years ago

After some time reverse engineering and debugging I found the problem. It is the same one described here and solved by adding coherent_pool=4M to the kernel boot line.