tree: https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git dbc head: 595547d1cfa3f6c591ea084cc1f77cd45bd81213 commit: 595547d1cfa3f6c591ea084cc1f77cd45bd81213 [5/5] xhci: dbgtty: use IDR to support several dbc instances. config: riscv-randconfig-m031-20220118 (https://download.01.org/0day-ci/archive/20220120/202201200955.C9pzrtCw-lk...) compiler: riscv32-linux-gcc (GCC) 11.2.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; smatch warnings: drivers/usb/host/xhci-dbgtty.c:423 xhci_dbc_tty_register_device() warn: unsigned 'port->minor' is never less than zero. vim +423 drivers/usb/host/xhci-dbgtty.c 407 408 static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc) 409 { 410 int ret; 411 struct device *tty_dev; 412 struct dbc_port *port = dbc_to_port(dbc); 413 414 if (port->registered) 415 return -EBUSY; 416 417 xhci_dbc_tty_init_port(dbc, port); 418 419 mutex_lock(&dbc_tty_minors_lock); 420 port->minor = idr_alloc(&dbc_tty_minors, port, 0, 64, GFP_KERNEL); 421 mutex_unlock(&dbc_tty_minors_lock); 422 424 ret = port->minor; 425 goto err_idr; 426 } 427 428 ret = kfifo_alloc(&port->write_fifo, DBC_WRITE_BUF_SIZE, GFP_KERNEL); 429 if (ret) 430 goto err_exit_port; 431 432 ret = xhci_dbc_alloc_requests(dbc, BULK_IN, &port->read_pool, 433 dbc_read_complete); 434 if (ret) 435 goto err_free_fifo; 436 437 ret = xhci_dbc_alloc_requests(dbc, BULK_OUT, &port->write_pool, 438 dbc_write_complete); 439 if (ret) 440 goto err_free_requests; 441 442 tty_dev = tty_port_register_device(&port->port, 443 dbc_tty_driver, port->minor, NULL); 444 if (IS_ERR(tty_dev)) { 445 ret = PTR_ERR(tty_dev); 446 goto err_free_requests; 447 } 448 449 port->registered = true; 450 451 return 0; 452 453 err_free_requests: 454 xhci_dbc_free_requests(&port->read_pool); 455 xhci_dbc_free_requests(&port->write_pool); 456 err_free_fifo: 457 kfifo_free(&port->write_fifo); 458 err_exit_port: 459 idr_remove(&dbc_tty_minors, port->minor); 460 err_idr: 461 xhci_dbc_tty_exit_port(port); 462 463 dev_err(dbc->dev, "can't register tty port, err %d\n", ret); 464 465 return ret; 466 } 467 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org