Bug 60815 - Interface hangs in mwifiex_usb
https://bugzilla.kernel.org/show_bug.cgi?id=60815
We have 4 bytes of interface header for packets delivered to SDIO
and PCIe, but not for USB interface.
In Tx AMSDU case, currently 4 bytes of garbage data is unnecessarily
appended for USB packets. This sometimes leads to a firmware hang,
because it may not interpret the data packet correctly.
Problem is fixed by removing this redundant headroom for USB.