Re: [PATCH next] Bluetooth: l2cap: protect conn refcnt under hci dev lock

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

Hi Lizhi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20250207]

url:    https://github.com/intel-lab-lkp/linux/commits/Lizhi-Xu/Bluetooth-l2cap-protect-conn-refcnt-under-hci-dev-lock/20250207-221142
base:   next-20250207
patch link:    https://lore.kernel.org/r/20250207140216.3076952-1-lizhi.xu%40windriver.com
patch subject: [PATCH next] Bluetooth: l2cap: protect conn refcnt under hci dev lock
config: i386-buildonly-randconfig-001-20250208 (https://download.01.org/0day-ci/archive/20250208/202502081633.z7O9VFNy-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250208/202502081633.z7O9VFNy-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/202502081633.z7O9VFNy-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> net/bluetooth/l2cap_core.c:7477:27: warning: 'l2cap_conn_hold_unless_zero' defined but not used [-Wunused-function]
    7477 | static struct l2cap_conn *l2cap_conn_hold_unless_zero(struct l2cap_conn *c)
         |                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/l2cap_conn_hold_unless_zero +7477 net/bluetooth/l2cap_core.c

4d7ea8ee90e42f Luiz Augusto von Dentz 2021-01-13  7476  
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16 @7477  static struct l2cap_conn *l2cap_conn_hold_unless_zero(struct l2cap_conn *c)
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7478  {
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7479  	BT_DBG("conn %p orig refcnt %u", c, kref_read(&c->ref));
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7480  
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7481  	if (!kref_get_unless_zero(&c->ref))
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7482  		return NULL;
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7483  
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7484  	return c;
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7485  }
6ab54a71718943 Luiz Augusto von Dentz 2025-01-16  7486  

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