Hello I have a USB based ID 148f:3070 Ralink Technology, Corp. RT2870/RT3070 Wireless Adapter, that stops working with recent kernels. It works on kernel 5.1.15 and does not work with 5.2.7 or 5.3.1 (I have not tested other versions). I use it in AP mode.

I found this similar bug report https://marc.info/?l=linux-wireless&m=156630037103575&w=2 but that did not have related error messages so I assume this is different?

Logs of working kernel 5.1.15-arch1-1-ARCH.
[   78.680555] ieee80211 phy0: rt2x00_set_rt: Info - RT chipset 3070, rev 0201 detected
[   78.690992] ieee80211 phy0: rt2x00_set_rf: Info - RF chipset 0005 detected
[   78.799625] ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
sep 26 17:13:03 kernel: usbcore: registered new interface driver rt2800usb
sep 26 17:13:03 systemd[1]: Found device RT2870/RT3070 Wireless Adapter.
[  113.812454] ieee80211 phy0: rt2x00lib_request_firmware: Info - Loading firmware file 'rt2870.bin'
[  113.905279] ieee80211 phy0: rt2x00lib_request_firmware: Info - Firmware detected - version: 0.36
[  114.028703] ieee80211 phy0: rt2x00usb_vendor_request: Error - Vendor Request 0x06 failed for offset 0x0404 with error -71

The last error there does not seem to affect the operation of the device.

Logs of not working with kernel 5.3.1, 5.2.7 has similar output.
sep 26 17:06:12 kernel: ieee80211 phy0: rt2x00_set_rt: Info - RT chipset 3070, rev 0201 detected
sep 26 17:06:12 kernel: ieee80211 phy0: rt2x00_set_rf: Info - RF chipset 0005 detected
sep 26 17:06:12 kernel: ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
sep 26 17:06:12 kernel: usbcore: registered new interface driver rt2800usb
sep 26 17:06:12 systemd[1]: Found device RT2870/RT3070 Wireless Adapter.
sep 26 17:06:21 ieee80211 phy0: rt2x00lib_request_firmware: Info - Loading firmware file 'rt2870.bin'
sep 26 17:06:21 ieee80211 phy0: rt2x00lib_request_firmware: Info - Firmware detected - version: 0.36
sep 26 17:06:21 ieee80211 phy0: rt2x00usb_vendor_request: Error - Vendor Request 0x06 failed for offset 0x0404 with>
sep 26 17:06:22 ieee80211 phy0: rt2800_wait_csr_ready: Error - Unstable hardware
sep 26 17:06:22 ieee80211 phy0: rt2800usb_set_device_state: Error - Device failed to enter state 4 (-5)

Unable to bring up the network interface here.

Tell me if you want me to run any commands or test any patches.