From 6c6967906305e4681c555338d8ad8823e8487c42 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Fri, 1 Jun 2012 11:29:40 +0200 Subject: rt2x00: use atomic variable for seqno commit e5851dac2c95af7159716832300b9f50c62c648e upstream. Remove spinlock as atomic_t can be used instead. Note we use only 16 lower bits, upper bits are changed but we impilcilty cast to u16. This fix possible deadlock on IBSS mode reproted by lockdep: ================================= [ INFO: inconsistent lock state ] 3.4.0-wl+ #4 Not tainted --------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kworker/u:2/30374 [HC0[0]:SC0[0]:HE1:SE1] takes: (&(&intf->seqlock)->rlock){+.?...}, at: [] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] {IN-SOFTIRQ-W} state was registered at: [] __lock_acquire+0x47b/0x1050 [] lock_acquire+0x84/0xf0 [] _raw_spin_lock+0x33/0x40 [] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [] rt2x00queue_write_tx_frame+0x1a/0x300 [rt2x00lib] [] rt2x00mac_tx+0x7f/0x380 [rt2x00lib] [] __ieee80211_tx+0x1b3/0x300 [mac80211] [] ieee80211_tx+0x105/0x130 [mac80211] [] ieee80211_xmit+0xad/0x100 [mac80211] [] ieee80211_subif_start_xmit+0x2d9/0x930 [mac80211] [] dev_hard_start_xmit+0x307/0x660 [] sch_direct_xmit+0xa1/0x1e0 [] dev_queue_xmit+0x183/0x730 [] neigh_resolve_output+0xfa/0x1e0 [] ip_finish_output+0x24a/0x460 [] ip_output+0xb7/0x100 [] ip_local_out+0x20/0x60 [] igmpv3_sendpack+0x4f/0x60 [] igmp_ifc_timer_expire+0x29f/0x330 [] run_timer_softirq+0x15c/0x2f0 [] __do_softirq+0xae/0x1e0 irq event stamp: 18380437 hardirqs last enabled at (18380437): [] __slab_alloc.clone.3+0x67/0x5f0 hardirqs last disabled at (18380436): [] __slab_alloc.clone.3+0x33/0x5f0 softirqs last enabled at (18377616): [] __do_softirq+0x123/0x1e0 softirqs last disabled at (18377611): [] do_softirq+0x9d/0xe0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&intf->seqlock)->rlock); lock(&(&intf->seqlock)->rlock); *** DEADLOCK *** 4 locks held by kworker/u:2/30374: #0: (wiphy_name(local->hw.wiphy)){++++.+}, at: [] process_one_work+0x109/0x3f0 #1: ((&sdata->work)){+.+.+.}, at: [] process_one_work+0x109/0x3f0 #2: (&ifibss->mtx){+.+.+.}, at: [] ieee80211_ibss_work+0x1b/0x470 [mac80211] #3: (&intf->beacon_skb_mutex){+.+...}, at: [] rt2x00queue_update_beacon+0x24/0x50 [rt2x00lib] stack backtrace: Pid: 30374, comm: kworker/u:2 Not tainted 3.4.0-wl+ #4 Call Trace: [] print_usage_bug+0x1f6/0x220 [] mark_lock+0x2c2/0x300 [] ? check_usage_forwards+0xc0/0xc0 [] __lock_acquire+0x4bc/0x1050 [] ? __kmalloc_track_caller+0x1c0/0x1d0 [] ? copy_skb_header+0x26/0x90 [] lock_acquire+0x84/0xf0 [] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [] _raw_spin_lock+0x33/0x40 [] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [] rt2x00queue_update_beacon_locked+0x5f/0xb0 [rt2x00lib] [] rt2x00queue_update_beacon+0x2d/0x50 [rt2x00lib] [] rt2x00mac_bss_info_changed+0x1ca/0x200 [rt2x00lib] [] ? rt2x00mac_remove_interface+0x70/0x70 [rt2x00lib] [] ieee80211_bss_info_change_notify+0xe0/0x1d0 [mac80211] [] __ieee80211_sta_join_ibss+0x3b8/0x610 [mac80211] [] ? mark_held_locks+0x64/0xc0 [] ? virt_efi_query_capsule_caps+0x12/0x50 [] ieee80211_sta_join_ibss+0xf9/0x140 [mac80211] [] ieee80211_ibss_work+0x416/0x470 [mac80211] [] ? trace_hardirqs_on+0xb/0x10 [] ? skb_dequeue+0x4b/0x70 [] ieee80211_iface_work+0x13f/0x230 [mac80211] [] ? process_one_work+0x109/0x3f0 [] process_one_work+0x185/0x3f0 [] ? process_one_work+0x109/0x3f0 [] ? ieee80211_teardown_sdata+0xa0/0xa0 [mac80211] [] worker_thread+0x116/0x270 [] ? manage_workers+0x1e0/0x1e0 [] kthread+0x84/0x90 [] ? __init_kthread_worker+0x60/0x60 [] kernel_thread_helper+0x6/0x10 Signed-off-by: Stanislaw Gruszka Acked-by: Helmut Schaa Acked-by: Gertjan van Wingerde Signed-off-by: John W. Linville Signed-off-by: Ben Hutchings --- drivers/net/wireless/rt2x00/rt2x00mac.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/net/wireless/rt2x00/rt2x00mac.c') diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c index 373dae1f51d8..921da9a67201 100644 --- a/drivers/net/wireless/rt2x00/rt2x00mac.c +++ b/drivers/net/wireless/rt2x00/rt2x00mac.c @@ -277,7 +277,6 @@ int rt2x00mac_add_interface(struct ieee80211_hw *hw, else rt2x00dev->intf_sta_count++; - spin_lock_init(&intf->seqlock); mutex_init(&intf->beacon_skb_mutex); intf->beacon = entry; -- cgit v1.2.3