BUILD_OK
case A (perpetual BUSY, real timeout): error=0x0 -> *** SMB_ETIMEOUT MISSING: kernel reports SUCCESS on wedged bus ***
case B (INTR on final poll, success):   error=0x20 -> *** SPURIOUS SMB_ETIMEOUT on successful transaction ***
cc 8.3 [DragonFly] Release/2019-02-22