tree: https://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap.git serdev-ngsm-pending-v5.7 head: 4eda51fea6be98ca5a4023a988b102bf3629b295 commit: c19326e2c3e68ca54628039dd7b79b8ff0e44680 [17/29] tty: n_gsm: Add support for serdev drivers config: nios2-randconfig-r032-20200522 (attached as .config) compiler: nios2-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout c19326e2c3e68ca54628039dd7b79b8ff0e44680 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=nios2 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): drivers/tty/n_gsm.c: In function 'gsm_serdev_register_dlci': 2564 | struct gsm_mux *gsm; | ^~~ drivers/tty/n_gsm.c: In function 'gsm_serdev_unregister_dlci': drivers/tty/n_gsm.c:2621:18: warning: variable 'gsm' set but not used [-Wunused-but-set-variable] 2621 | struct gsm_mux *gsm; | ^~~ vim +/gsm +2564 drivers/tty/n_gsm.c 2554 2555 /** 2556 * gsm_serdev_register_dlci - register a ts 27.010 channel 2557 * @gsd: serdev-gsm instance 2558 * @ops: channel ops 2559 */ 2560 int gsm_serdev_register_dlci(struct gsm_serdev *gsd, 2561 struct gsm_serdev_dlci *ops) 2562 { 2563 struct gsm_dlci *dlci; 2565 int retries; 2566 2567 if (!gsd || !gsd->gsm || !gsd->serdev) 2568 return -ENODEV; 2569 2570 gsm = gsd->gsm; 2571 2572 if (!ops || !ops->line) 2573 return -EINVAL; 2574 2575 dlci = gsd_dlci_get(gsd, ops->line, true); 2576 if (IS_ERR(dlci)) 2577 return PTR_ERR(dlci); 2578 2579 if (dlci->state == DLCI_OPENING || dlci->state == DLCI_OPEN || 2580 dlci->state == DLCI_CLOSING) 2581 return -EBUSY; 2582 2583 mutex_lock(&dlci->mutex); 2584 ops->gsd = gsd; 2585 dlci->ops = ops; 2586 dlci->modem_rx = 0; 2587 dlci->prev_data = dlci->data; 2588 dlci->data = gsd_dlci_data; 2589 mutex_unlock(&dlci->mutex); 2590 2591 gsm_dlci_begin_open(dlci); 2592 2593 /* 2594 * Allow some time for dlci to move to DLCI_OPEN state. Otherwise 2595 * the serdev consumer driver can start sending data too early during 2596 * the setup, and the response will be missed by gms_queue() if we 2597 * still have DLCI_CLOSED state. 2598 */ 2599 for (retries = 10; retries > 0; retries--) { 2600 if (dlci->state == DLCI_OPEN) 2601 break; 2602 msleep(100); 2603 } 2604 2605 if (!retries) 2606 dev_dbg(&gsd->serdev->dev, "dlci%i not currently active\n", 2607 dlci->addr); 2608 2609 return 0; 2610 } 2611 EXPORT_SYMBOL_GPL(gsm_serdev_register_dlci); 2612 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org