Hi Anish, FYI, here is one more bug message for git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master commit 759a0cc5a3e1bc2cc48fa3c0b91bdcad8b8f87d6 ("cxgb4i: Add ipv6 code to driver, call into libcxgbi ipv6 api") [ 7.671997] Key type encrypted registered [ 7.676647] [ 7.676874] =============================== [ 7.677354] [ INFO: suspicious RCU usage. ] [ 7.677867] 3.16.0-rc6-01233-gac3d2e5 #1272 Not tainted [ 7.678466] ------------------------------- [ 7.678973] include/linux/rcupdate.h:513 Illegal context switch in RCU read-side critical section! [ 7.680252] [ 7.680252] other info that might help us debug this: [ 7.680252] [ 7.681194] [ 7.681194] rcu_scheduler_active = 1, debug_locks = 1 [ 7.682071] 3 locks held by swapper/1: [ 7.682667] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x19 [ 7.683990] #1: (rcu_read_lock){......}, at: [] __atomic_notifier_call_chain+0x5/0x105 [ 7.685606] #2: (rcu_read_lock){......}, at: [] cxgbi_inet6addr_handler+0x5/0x202 [ 7.687150] [ 7.687150] stack backtrace: [ 7.687837] CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-rc6-01233-gac3d2e5 #1272 [ 7.689016] 0000000000000000 ffff880100d639f8 ffffffff87e25ccc ffff880100d63a28 [ 7.690951] ffffffff86cbc38c ffffffff885d9370 000000000000024a 0000000000000000 [ 7.692164] ffff880100c66000 ffff880100d63a50 ffffffff86cadfd4 ffffffff88ad4d90 [ 7.693375] Call Trace: [ 7.693795] [] dump_stack+0x19/0x1b [ 7.694579] [] lockdep_rcu_suspicious+0xe9/0xf2 [ 7.695533] [] __might_sleep+0x58/0x1e9 [ 7.696372] [] mutex_lock_nested+0x3b/0x3d3 [ 7.697265] [] ? sched_clock_local.constprop.2+0x34/0xa1 [ 7.698323] [] cxgbi_device_find_by_netdev+0x63/0x102 [ 7.699359] [] cxgbi_inet6addr_handler+0xa1/0x202 [ 7.700380] [] ? cxgbi_inet6addr_handler+0x5/0x202 [ 7.701384] [] notifier_call_chain+0xf4/0x126 [ 7.702322] [] __atomic_notifier_call_chain+0x9c/0x105 [ 7.703366] [] ? __atomic_notifier_call_chain+0x5/0x105 [ 7.704241] [] atomic_notifier_call_chain+0x14/0x16 [ 7.705234] [] inet6addr_notifier_call_chain+0x1b/0x1d [ 7.706505] [] ipv6_add_addr+0x218/0x544 [ 7.707539] [] ? ipv6_add_addr+0x65/0x544 [ 7.708484] [] add_addr+0x31/0x93 [ 7.709420] [] addrconf_notify+0x65e/0x9b9 [ 7.710559] [] ? _raw_read_unlock+0x27/0x31 [ 7.711523] [] ? __lock_is_held+0x37/0x4f [ 7.712588] [] notifier_call_chain+0xf4/0x126 [ 7.713683] [] raw_notifier_call_chain+0x14/0x16 [ 7.714706] [] call_netdevice_notifiers_info+0x71/0x7a [ 7.715987] [] call_netdevice_notifiers+0x13/0x15 [ 7.717071] [] __dev_notify_flags+0x54/0x82 [ 7.718127] [] dev_change_flags+0x4d/0x58 [ 7.719187] [] ip_auto_config+0x177/0xdbf [ 7.720146] [] ? slob_free+0x2cb/0x2d8 [ 7.721173] [] ? root_nfs_parse_addr+0xa3/0xaf [ 7.722309] [] ? do_one_initcall+0x98/0x1d0 [ 7.723252] [] ? root_nfs_parse_addr+0xaf/0xaf [ 7.724522] [] do_one_initcall+0x1bb/0x1d0 [ 7.725547] [] ? param_array_set+0x82/0x11e [ 7.726539] [] ? parse_args+0x1a5/0x27f [ 7.727463] [] kernel_init_freeable+0xf8/0x17d [ 7.728598] [] ? initcall_blacklist+0x9f/0x9f [ 7.729585] [] ? rest_init+0x136/0x136 [ 7.730678] [] kernel_init+0xe/0xda [ 7.731661] [] ret_from_fork+0x7a/0xb0 [ 7.732532] [] ? rest_init+0x136/0x136 [ 7.734390] IP-Config: Failed to open gretap0 [ 7.735138] IP-Config: No network devices available [ 7.736057] ALSA device list: Thanks, Fengguang