Hi Samuel, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: dcc0b49040c70ad827a7f3d58a21b01fdb14e749 commit: 2067fd92d75b6d9085a43caf050bca5d88c491b8 staging/speakup: Move out of staging date: 7 months ago config: parisc-randconfig-r025-20210212 (attached as .config) compiler: hppa-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 # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 2067fd92d75b6d9085a43caf050bca5d88c491b8 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc 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 >>): drivers/accessibility/speakup/serialio.c: In function 'spk_serial_init': 48 | int baud = 9600, quot = 0; | ^~~~ drivers/accessibility/speakup/serialio.c: In function 'spk_serial_tiocmset': drivers/accessibility/speakup/serialio.c:165:6: warning: unused variable 'old' [-Wunused-variable] 165 | int old = inb(speakup_info.port_tts + UART_MCR); | ^~~ vim +/quot +48 drivers/accessibility/speakup/serialio.c 1e441594e509c3 drivers/staging/speakup/serialio.c Okash Khawaja 2017-03-14 45 3ee0017e03cd79 drivers/staging/speakup/serialio.c Jiri Slaby 2012-03-05 46 const struct old_serial_port *spk_serial_init(int index) c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 47 { c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 @48 int baud = 9600, quot = 0; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 49 unsigned int cval = 0; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 50 int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8; 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 51 const struct old_serial_port *ser; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 52 int err; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 53 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 54 if (index >= ARRAY_SIZE(rs_table)) { 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 55 pr_info("no port info for ttyS%d\n", index); 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 56 return NULL; 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 57 } 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 58 ser = rs_table + index; 327b882d3bcc1f drivers/staging/speakup/serialio.c Samuel Thibault 2016-01-15 59 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 60 /* Divisor, bytesize and parity */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 61 quot = ser->baud_base / baud; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 62 cval = cflag & (CSIZE | CSTOPB); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 63 #if defined(__powerpc__) || defined(__alpha__) c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 64 cval >>= 8; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 65 #else /* !__powerpc__ && !__alpha__ */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 66 cval >>= 4; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 67 #endif /* !__powerpc__ && !__alpha__ */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 68 if (cflag & PARENB) c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 69 cval |= UART_LCR_PARITY; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 70 if (!(cflag & PARODD)) c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 71 cval |= UART_LCR_EPAR; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 72 if (synth_request_region(ser->port, 8)) { c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 73 /* try to take it back. */ 3a046c19158e89 drivers/staging/speakup/serialio.c Keerthimai Janarthanan 2014-03-18 74 pr_info("Ports not available, trying to steal them\n"); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 75 __release_region(&ioport_resource, ser->port, 8); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 76 err = synth_request_region(ser->port, 8); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 77 if (err) { 3ee0017e03cd79 drivers/staging/speakup/serialio.c Jiri Slaby 2012-03-05 78 pr_warn("Unable to allocate port at %x, errno %i", baf9ac9ff8864c drivers/staging/speakup/serialio.c William Hubbs 2010-10-15 79 ser->port, err); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 80 return NULL; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 81 } c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 82 } c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 83 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 84 /* Disable UART interrupts, set DTR and RTS high 13d825edd4441d drivers/staging/speakup/serialio.c Aleksei Fedotov 2015-08-14 85 * and set speed. 13d825edd4441d drivers/staging/speakup/serialio.c Aleksei Fedotov 2015-08-14 86 */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 87 outb(cval | UART_LCR_DLAB, ser->port + UART_LCR); /* set DLAB */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 88 outb(quot & 0xff, ser->port + UART_DLL); /* LS of divisor */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 89 outb(quot >> 8, ser->port + UART_DLM); /* MS of divisor */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 90 outb(cval, ser->port + UART_LCR); /* reset DLAB */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 91 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 92 /* Turn off Interrupts */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 93 outb(0, ser->port + UART_IER); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 94 outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 95 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 96 /* If we read 0xff from the LSR, there is no UART here. */ c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 97 if (inb(ser->port + UART_LSR) == 0xff) { c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 98 synth_release_region(ser->port, 8); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 99 serstate = NULL; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 100 return NULL; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 101 } c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 102 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 103 mdelay(1); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 104 speakup_info.port_tts = ser->port; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 105 serstate = ser; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 106 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 107 start_serial_interrupt(ser->irq); c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 108 c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 109 return ser; c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 110 } c6e3fd22cd5383 drivers/staging/speakup/serialio.c William Hubbs 2010-10-07 111 :::::: The code at line 48 was first introduced by commit :::::: c6e3fd22cd538365bfeb82997d5b89562e077d42 Staging: add speakup to the staging directory :::::: TO: William Hubbs <w.d.hubbs(a)gmail.com&gt; :::::: CC: Greg Kroah-Hartman <gregkh(a)suse.de&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org