Reproducer: ./x86_64-softmmu/qemu-system-x86_64 -device usb-ccid,id=ccid0 -usb -device ccid-card-emulated -monitor stdio
Signed-off-by: Cole Robinson <crobi...@redhat.com> --- hw/usb/ccid-card-emulated.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/hw/usb/ccid-card-emulated.c b/hw/usb/ccid-card-emulated.c index 29dcd7a..65e1432 100644 --- a/hw/usb/ccid-card-emulated.c +++ b/hw/usb/ccid-card-emulated.c @@ -500,9 +500,15 @@ static int emulated_initfn(CCIDCardState *base) if (init_pipe_signaling(card) < 0) { return -1; } - card->backend = parse_enumeration(card->backend_str, backend_enum_table, 0); + + card->backend = 0; + if (card->backend_str) { + card->backend = parse_enumeration(card->backend_str, + backend_enum_table, 0); + } + if (card->backend == 0) { - printf("unknown backend, must be one of:\n"); + printf("backend must be one of:\n"); for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) { printf("%s\n", ptable->name); } -- 1.8.1.4