I have a Sierra Wireless MC7430 USB 3.0 LTE modem running on a custom board which is based on the MT7621A SoC. I'm using the USB 3.0 drivers. Lately it seems when I do anything bandwidth-intensive such as a speed test, or after at least 9 hours of uptime with normal usage, I will start seeing this "event type 37 error". I can't be sure yet but it seems like it usually happens after the bandwidth has gone above 40Mbps. Occasionally the modem cannot recover (unsure if this is the cause, but seems likely at this stage) and needs to be reset, which means rebooting the board.
Any hints on what this is, or the cause? I read that this might be the usb controller's ring buffer becoming full, but can't confirm.
[ 242.657691] xhci-mtk 1e1c0000.xhci: ERROR unknown event type 37 [ 244.717622] xhci-mtk 1e1c0000.xhci: ERROR unknown event type 37
USB Kernel modules, and I am on kernel 4.14.95, OpenWrt 18.06.2.
kmod-usb-acm - 4.14.95-1 kmod-usb-core - 4.14.95-1 kmod-usb-net - 4.14.95-1 kmod-usb-net-cdc-ether - 4.14.95-1 kmod-usb-net-cdc-mbim - 4.14.95-1 kmod-usb-net-cdc-ncm - 4.14.95-1 kmod-usb-net-hso - 4.14.95-1 kmod-usb-net-huawei-cdc-ncm - 4.14.95-1 kmod-usb-net-qmi-wwan - 4.14.95-1 kmod-usb-net-rndis - 4.14.95-1 kmod-usb-net-sierrawireless - 4.14.95-1 kmod-usb-serial - 4.14.95-1 kmod-usb-serial-option - 4.14.95-1 kmod-usb-serial-qualcomm - 4.14.95-1 kmod-usb-serial-sierrawireless - 4.14.95-1 kmod-usb-serial-wwan - 4.14.95-1 kmod-usb-wdm - 4.14.95-1 kmod-usb3 - 4.14.95-1 libusb-1.0 - 1.0.22-1