Comment 200 for bug 1667750

Now running mainline kernel 5.2 and the issue still exists.
Tested on this device:
ID 148f:3070 Ralink Technology, Corp. RT2870/RT3070 Wireless Adapter
but the same applies to many other devices, too

dmesg after plug in the device:

[75.482165] usb 1-2: new high-speed USB device number 6 using xhci_hcd
[75.639236] usb 1-2: New USB device found, idVendor=148f, idProduct=3070, bcdDevice= 1.01
[75.639238] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[75.639239] usb 1-2: Product: 802.11 n WLAN
[75.639240] usb 1-2: Manufacturer: Ralink
[75.639241] usb 1-2: SerialNumber: 1.0
[75.952611] usb 1-2: reset high-speed USB device number 6 using xhci_hcd
[76.107232] ieee80211 phy1: rt2x00_set_rt: Info - RT chipset 3070, rev 0201 detected
[76.120228] ieee80211 phy1: rt2x00_set_rf: Info - RF chipset 0005 detected
[76.121079] ieee80211 phy1: Selected rate control algorithm 'minstrel_ht'
[76.130873] usbcore: registered new interface driver rt2800usb
[76.194447] audit: type=1130 audit(1562833499.983:49): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-rfkill comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[76.195313] rt2800usb 1-2:1.0 wlp0s20f0u2: renamed from wlan0
[76.216178] ieee80211 phy1: rt2x00lib_request_firmware: Info - Loading firmware file 'rt2870.bin'
[76.241382] ieee80211 phy1: rt2x00lib_request_firmware: Info - Firmware detected - version: 0.36
[76.544022] ieee80211 phy1: rt2x00usb_vendor_request: Error - Vendor Request 0x06 failed for offset 0x0404 with error -71
[77.562305] ieee80211 phy1: rt2800_wait_csr_ready: Error - Unstable hardware
[77.562316] ieee80211 phy1: rt2800usb_set_device_state: Error - Device failed to enter state 4 (-5)
...
followed by this message on access to the interface:
[341.598563] xhci_hcd 0000:00:14.0: WARN Cannot submit Set TR Deq Ptr
[341.598573] xhci_hcd 0000:00:14.0: A Set TR Deq Ptr command is pending.