On Mon, 23 Dec 2019, Mathias Nyman wrote: > The Maximum Packet Size of the full-speed bulk endpoint looks a bit suspicious (maxp 4) > > 12478.521580: xhci_add_endpoint: State disabled mult 1 max P. Streams 0 interval 125 us max ESIT payload 0 CErr 3 Type Bulk OUT burst 0 maxp 4 deq 00000000fff71001 > > For full speed bulk endpoints only support 8, 16, 32 and 64 bytes Max Packet sizes. > Host are not required to support other values. See USB2 spec section 5.8.3 for details > > Maybe forcing it to one of the allowed values could work. > Does the below hack help? (untested)? Is this the sort of thing we should handle in config.c:usb_parse_endpoint()? Even though 4 is not a valid maxpacket size for full-speed bulk endpoints, many host controllers and hubs will handle it okay. Much the same is true for devices that have a high-speed bulk endpoint with maxpacket set to 1024. Should we try to treat these two errors the same way? Alan Stern
