Hi Tony, I love your patch! Perhaps something to improve: [auto build test WARNING on usb/usb-testing] [also build test WARNING on v5.16-rc1 next-20211116] [cannot apply to tty/tty-testing] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Tony-Lindgren/Serial-port-generi... base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing config: hexagon-randconfig-r045-20211115 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project fbe72e41b99dc7994daac300d208a955be3e4a0a) 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 # https://github.com/0day-ci/linux/commit/d9568fa846ba1319eacfd03d39b48c3af... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Tony-Lindgren/Serial-port-generic-PM-to-fix-8250-PM/20211115-164354 git checkout d9568fa846ba1319eacfd03d39b48c3af05fe9f9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=hexagon If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): if (tty_port_suspended(port)) { ^~~~~~~~~~~~~~~~~~~~~~~~ drivers/tty/serial/serial_core.c:2401:9: note: uninitialized use occurs here return ret; ^~~ drivers/tty/serial/serial_core.c:2353:2: note: remove the 'if' if its condition is always true if (tty_port_suspended(port)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/tty/serial/serial_core.c:2310:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +2353 drivers/tty/serial/serial_core.c ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2302 ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2303 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2304 { ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2305 struct uart_state *state = drv->state + uport->line; ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2306 struct tty_port *port = &state->port; 03a74dcc7eebe6 drivers/serial/serial_core.c Arjan van de Ven 2008-05-23 2307 struct device *tty_dev; ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2308 struct uart_match match = {uport, drv}; ba15ab0e8de0d4 drivers/serial/serial_core.c Deepak Saxena 2009-09-19 2309 struct ktermios termios; d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2310 int ret; ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2311 a2bceae065ed8c drivers/serial/serial_core.c Alan Cox 2009-09-19 2312 mutex_lock(&port->mutex); ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2313 ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2314 tty_dev = device_find_child(uport->dev, &match, serial_match_port); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2315 if (!uport->suspended && device_may_wakeup(tty_dev)) { aef3ad103a686f drivers/tty/serial/serial_core.c Andy Shevchenko 2017-08-13 2316 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq)))) ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2317 disable_irq_wake(uport->irq); 5a65dcc04cda41 drivers/tty/serial/serial_core.c Federico Vaga 2013-04-15 2318 put_device(tty_dev); a2bceae065ed8c drivers/serial/serial_core.c Alan Cox 2009-09-19 2319 mutex_unlock(&port->mutex); b3b708fa2780cd drivers/serial/serial_core.c Guennadi Liakhovetski 2007-10-16 2320 return 0; b3b708fa2780cd drivers/serial/serial_core.c Guennadi Liakhovetski 2007-10-16 2321 } 5a65dcc04cda41 drivers/tty/serial/serial_core.c Federico Vaga 2013-04-15 2322 put_device(tty_dev); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2323 uport->suspended = 0; b3b708fa2780cd drivers/serial/serial_core.c Guennadi Liakhovetski 2007-10-16 2324 ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2325 /* ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2326 * Re-enable the console device after suspending. ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2327 */ 5933a161abcb8d drivers/tty/serial/serial_core.c Yin Kangkai 2011-01-30 2328 if (uart_console(uport)) { 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2329 /* 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2330 * First try to use the console cflag setting. 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2331 */ 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2332 memset(&termios, 0, sizeof(struct ktermios)); 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2333 termios.c_cflag = uport->cons->cflag; 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2334 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2335 /* 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2336 * If that's unset, use the tty termios setting. 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2337 */ adc8d746caa67f drivers/tty/serial/serial_core.c Alan Cox 2012-07-14 2338 if (port->tty && termios.c_cflag == 0) adc8d746caa67f drivers/tty/serial/serial_core.c Alan Cox 2012-07-14 2339 termios = port->tty->termios; 891b9dd1076435 drivers/serial/serial_core.c Jason Wang 2010-08-21 2340 d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2341 ret = serial_pm_resume_and_get(uport->dev); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2342 if (ret < 0) d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2343 goto unlock; 94abc56f4d90f2 drivers/tty/serial/serial_core.c Ning Jiang 2011-09-05 2344 if (console_suspend_enabled) 6f538fe31c1d45 drivers/tty/serial/serial_core.c Linus Walleij 2012-12-07 2345 uart_change_pm(state, UART_PM_STATE_ON); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2346 uport->ops->set_termios(uport, &termios, NULL); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2347 serial_pm_autosuspend(uport->dev); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2348 5933a161abcb8d drivers/tty/serial/serial_core.c Yin Kangkai 2011-01-30 2349 if (console_suspend_enabled) ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2350 console_start(uport->cons); ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2351 } ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2352 80f02d5424301b drivers/tty/serial/serial_core.c Peter Hurley 2016-04-09 @2353 if (tty_port_suspended(port)) { ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2354 const struct uart_ops *ops = uport->ops; ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2355 d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2356 ret = serial_pm_resume_and_get(uport->dev); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2357 if (ret < 0) d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2358 goto unlock; 6f538fe31c1d45 drivers/tty/serial/serial_core.c Linus Walleij 2012-12-07 2359 uart_change_pm(state, UART_PM_STATE_ON); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2360 spin_lock_irq(&uport->lock); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2361 ops->set_mctrl(uport, 0); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2362 spin_unlock_irq(&uport->lock); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2363 serial_pm_autosuspend(uport->dev); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2364 4547be7809a3b7 drivers/serial/serial_core.c Stanislav Brabec 2009-12-02 2365 if (console_suspend_enabled || !uart_console(uport)) { 192251352f912b drivers/serial/serial_core.c Alan Cox 2010-06-01 2366 /* Protected by port mutex for now */ 192251352f912b drivers/serial/serial_core.c Alan Cox 2010-06-01 2367 struct tty_struct *tty = port->tty; 4ed71addf51a62 drivers/tty/serial/serial_core.c Tamseel Shams 2020-07-16 2368 d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2369 ret = serial_pm_resume_and_get(uport->dev); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2370 if (ret < 0) d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2371 goto unlock; ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2372 ret = ops->startup(uport); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2373 serial_pm_autosuspend(uport->dev); ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2374 if (ret == 0) { 192251352f912b drivers/serial/serial_core.c Alan Cox 2010-06-01 2375 if (tty) 192251352f912b drivers/serial/serial_core.c Alan Cox 2010-06-01 2376 uart_change_speed(tty, state, NULL); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2377 ret = serial_pm_resume_and_get(uport->dev); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2378 if (ret < 0) d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2379 goto unlock; ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2380 spin_lock_irq(&uport->lock); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2381 ops->set_mctrl(uport, uport->mctrl); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2382 ops->start_tx(uport); ccce6debb62d94 drivers/serial/serial_core.c Alan Cox 2009-09-19 2383 spin_unlock_irq(&uport->lock); d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2384 serial_pm_autosuspend(uport->dev); d41861ca19c9e9 drivers/tty/serial/serial_core.c Peter Hurley 2016-04-09 2385 tty_port_set_initialized(port, 1); ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2386 } else { ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2387 /* ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2388 * Failed to resume - maybe hardware went away? ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2389 * Clear the "initialized" flag so we won't try ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2390 * to call the low level drivers shutdown method. ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2391 */ 192251352f912b drivers/serial/serial_core.c Alan Cox 2010-06-01 2392 uart_shutdown(tty, state); ee31b337852ca8 drivers/serial/serial_core.c Russell King 2005-11-13 2393 } 4547be7809a3b7 drivers/serial/serial_core.c Stanislav Brabec 2009-12-02 2394 } a6b93a90850881 drivers/serial/serial_core.c Russell King 2006-10-01 2395 80f02d5424301b drivers/tty/serial/serial_core.c Peter Hurley 2016-04-09 2396 tty_port_set_suspended(port, 0); ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2397 } d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2398 unlock: a2bceae065ed8c drivers/serial/serial_core.c Alan Cox 2009-09-19 2399 mutex_unlock(&port->mutex); ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2400 d9568fa846ba13 drivers/tty/serial/serial_core.c Andy Shevchenko 2021-11-15 2401 return ret; ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2402 } ^1da177e4c3f41 drivers/serial/serial_core.c Linus Torvalds 2005-04-16 2403 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org