Hi Zhenguo,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tty/tty-testing]
[also build test ERROR on v5.13 next-20210630]
[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/Zhenguo-Zhao/tty-n_gsm-delete-SABM-command-frame-as-requester/20210701-105612
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
config: m68k-randconfig-p001-20210630 (attached as .config)
compiler: m68k-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://github.com/0day-ci/linux/commit/a301defb207dd1f6e0de34d096f55ef6e550073c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Zhenguo-Zhao/tty-n_gsm-delete-SABM-command-frame-as-requester/20210701-105612
        git checkout a301defb207dd1f6e0de34d096f55ef6e550073c
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross O=build_dir ARCH=m68k SHELL=/bin/bash drivers/tty/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/tty/n_gsm.c: In function 'gsmtty_open':
>> drivers/tty/n_gsm.c:3012:6: error: 'gsm' undeclared (first use in this function)
    3012 |  if (gsm->initiator)
         |      ^~~
   drivers/tty/n_gsm.c:3012:6: note: each undeclared identifier is reported only once for each function it appears in


vim +/gsm +3012 drivers/tty/n_gsm.c

  2998	
  2999	static int gsmtty_open(struct tty_struct *tty, struct file *filp)
  3000	{
  3001		struct gsm_dlci *dlci = tty->driver_data;
  3002		struct tty_port *port = &dlci->port;
  3003	
  3004		port->count++;
  3005		tty_port_tty_set(port, tty);
  3006	
  3007		dlci->modem_rx = 0;
  3008		/* We could in theory open and close before we wait - eg if we get
  3009		   a DM straight back. This is ok as that will have caused a hangup */
  3010		tty_port_set_initialized(port, 1);
  3011		/* Start sending off SABM messages for initiator */
> 3012		if (gsm->initiator)
  3013			gsm_dlci_begin_open(dlci);
  3014		/* And wait for virtual carrier */
  3015		return tty_port_block_til_ready(port, tty, filp);
  3016	}
  3017	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org