[jirislaby:devel 15/79] drivers/tty/tty_io.c:1152:5: error: conflicting types for 'tty_send_xchar'; have 'int(struct tty_struct *, u8)' {aka 'int(struct tty_struct *, unsigned char)'}

[kernel test robot <lkp@intel.com>]

Hi Jiri,

FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/jirislaby/linux.git devel
head:   0c245952ee3106fad8a2fd3198a8e5c324e90992
commit: 44f1bce172713e922fd4fe273ad8d29e1a3e9321 [15/79] tty: make tty_operations::send_xchar accept u8 char
config: csky-randconfig-001-20231103 (https://download.01.org/0day-ci/archive/20231103/202311032318.2MP4TsV1-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231103/202311032318.2MP4TsV1-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311032318.2MP4TsV1-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/tty/tty_io.c:1152:5: error: conflicting types for 'tty_send_xchar'; have 'int(struct tty_struct *, u8)' {aka 'int(struct tty_struct *, unsigned char)'}
    1152 | int tty_send_xchar(struct tty_struct *tty, u8 ch)
         |     ^~~~~~~~~~~~~~
   In file included from drivers/tty/tty_io.c:76:
   include/linux/tty.h:413:5: note: previous declaration of 'tty_send_xchar' with type 'int(struct tty_struct *, char)'
     413 | int tty_send_xchar(struct tty_struct *tty, char ch);
         |     ^~~~~~~~~~~~~~


vim +1152 drivers/tty/tty_io.c

  1142	
  1143	/**
  1144	 * tty_send_xchar - send priority character
  1145	 * @tty: the tty to send to
  1146	 * @ch: xchar to send
  1147	 *
  1148	 * Send a high priority character to the tty even if stopped.
  1149	 *
  1150	 * Locking: none for xchar method, write ordering for write method.
  1151	 */
> 1152	int tty_send_xchar(struct tty_struct *tty, u8 ch)
  1153	{
  1154		bool was_stopped = tty->flow.stopped;
  1155	
  1156		if (tty->ops->send_xchar) {
  1157			down_read(&tty->termios_rwsem);
  1158			tty->ops->send_xchar(tty, ch);
  1159			up_read(&tty->termios_rwsem);
  1160			return 0;
  1161		}
  1162	
  1163		if (tty_write_lock(tty, false) < 0)
  1164			return -ERESTARTSYS;
  1165	
  1166		down_read(&tty->termios_rwsem);
  1167		if (was_stopped)
  1168			start_tty(tty);
  1169		tty->ops->write(tty, &ch, 1);
  1170		if (was_stopped)
  1171			stop_tty(tty);
  1172		up_read(&tty->termios_rwsem);
  1173		tty_write_unlock(tty);
  1174		return 0;
  1175	}
  1176	

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