On certain MT7601U adapters, such as Tenda U2 and other newer hardware revisions, driver initialization consistently fails during probe with vendor request timeouts (-110 / -ETIMEDOUT): mt7601u 3-14:1.0: ASIC revision: 76010001 MAC revision: 76010500 mt7601u 3-14:1.0: Firmware Version: 0.1.00 Build: 7640 Build time: 201302052146____ mt7601u 3-14:1.0: Vendor request req:07 off:09a8 failed:-110 mt7601u 3-14:1.0: Vendor request req:02 off:09a8 failed:-110 mt7601u 3-14:1.0: Vendor request req:07 off:0734 failed:-110 mt7601u 3-14:1.0: Vendor request req:42 off:0230 failed:-110 mt7601u 3-14:1.0: probe with driver mt7601u failed with error -110 The failure occurs because mt7601u_load_firmware() unconditionally calls mt7601u_vendor_reset() (MT_VEND_DEV_MODE_RESET) before uploading firmware chunks. On these devices, issuing this vendor reset leaves the internal MCU / FCE DMA engine in an unresponsive state after the first firmware URB is submitted. As a result, reading MT_TX_CPU_FROM_FCE_CPU_DESC_IDX (0x09a8) immediately times out. Introduce a boolean module parameter 'vnd_reset' (default: false) to make this vendor reset optional. When the vendor reset is skipped, firmware upload succeeds and the wireless interface initializes normally. Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1716301 More issues with Tenda U2 and Linux: - https://www.opena.tv/viewtopic.php?t=63919 - https://askubuntu.com/questions/1418850/the-problem-with-wi-fi-u2 - https://bbs.archlinux.org/viewtopic.php?id=224859 - https://www.reddit.com/r/archlinux/comments/1d6dfv5/mt7601u_usb_wifi_not_working/ Signed-off-by: Herman Semenoff