Re: [RFC net-next 2/4] net: Hold netdev instance lock during ndo_setup_tc

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

Hi Stanislav,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Stanislav-Fomichev/net-Hold-netdev-instance-lock-during-ndo_open-ndo_stop/20250205-070345
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250204230057.1270362-3-sdf%40fomichev.me
patch subject: [RFC net-next 2/4] net: Hold netdev instance lock during ndo_setup_tc
config: i386-buildonly-randconfig-002-20250205 (https://download.01.org/0day-ci/archive/20250205/202502052318.69Ey7176-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250205/202502052318.69Ey7176-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/202502052318.69Ey7176-lkp@intel.com/

All warnings (new ones prefixed by >>):

   net/sched/sch_taprio.c: In function 'taprio_disable_offload':
>> net/sched/sch_taprio.c:1567:38: warning: unused variable 'ops' [-Wunused-variable]
    1567 |         const struct net_device_ops *ops = dev->netdev_ops;
         |                                      ^~~


vim +/ops +1567 net/sched/sch_taprio.c

9c66d15646760e Vinicius Costa Gomes 2019-09-15  1562  
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1563  static int taprio_disable_offload(struct net_device *dev,
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1564  				  struct taprio_sched *q,
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1565  				  struct netlink_ext_ack *extack)
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1566  {
9c66d15646760e Vinicius Costa Gomes 2019-09-15 @1567  	const struct net_device_ops *ops = dev->netdev_ops;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1568  	struct tc_taprio_qopt_offload *offload;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1569  	int err;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1570  
db46e3a88a09c5 Vladimir Oltean      2022-09-15  1571  	if (!q->offloaded)
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1572  		return 0;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1573  
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1574  	offload = taprio_offload_alloc(0);
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1575  	if (!offload) {
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1576  		NL_SET_ERR_MSG(extack,
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1577  			       "Not enough memory to disable offload mode");
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1578  		return -ENOMEM;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1579  	}
2d800bc500fb3f Vladimir Oltean      2023-05-30  1580  	offload->cmd = TAPRIO_CMD_DESTROY;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1581  
4a7badd235a5c2 Stanislav Fomichev   2025-02-04  1582  	err = dev_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1583  	if (err < 0) {
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1584  		NL_SET_ERR_MSG(extack,
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1585  			       "Device failed to disable offload");
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1586  		goto out;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1587  	}
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1588  
db46e3a88a09c5 Vladimir Oltean      2022-09-15  1589  	q->offloaded = false;
db46e3a88a09c5 Vladimir Oltean      2022-09-15  1590  
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1591  out:
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1592  	taprio_offload_free(offload);
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1593  
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1594  	return err;
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1595  }
9c66d15646760e Vinicius Costa Gomes 2019-09-15  1596  

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