The current build shows a warning with the DTL-1 driver:
CC [M] drivers/bluetooth/dtl1_cs.o
drivers/bluetooth/dtl1_cs.c: In function ‘dtl1_hci_send_frame’:
drivers/bluetooth/dtl1_cs.c:396: warning: ‘nsh.type’ may be used uninitialized in this function
Fix this by adding a proper error for unknown packet types.