diff options
author | Stanislaw Gruszka <sgruszka@redhat.com> | 2012-06-01 11:29:40 +0200 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2012-06-19 23:18:12 +0100 |
commit | 6c6967906305e4681c555338d8ad8823e8487c42 (patch) | |
tree | ce2d697b120dd427fcc4e55f43e961b13ef85c69 /drivers/net/wireless/rt2x00/rt2x00mac.c | |
parent | 68d214eda1a87c9045ab8c5247d1911cfc47bede (diff) |
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: [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
{IN-SOFTIRQ-W} state was registered at:
[<c04978ab>] __lock_acquire+0x47b/0x1050
[<c0498504>] lock_acquire+0x84/0xf0
[<c0835733>] _raw_spin_lock+0x33/0x40
[<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
[<f9979f2a>] rt2x00queue_write_tx_frame+0x1a/0x300 [rt2x00lib]
[<f997834f>] rt2x00mac_tx+0x7f/0x380 [rt2x00lib]
[<f98fe363>] __ieee80211_tx+0x1b3/0x300 [mac80211]
[<f98ffdf5>] ieee80211_tx+0x105/0x130 [mac80211]
[<f99000dd>] ieee80211_xmit+0xad/0x100 [mac80211]
[<f9900519>] ieee80211_subif_start_xmit+0x2d9/0x930 [mac80211]
[<c0782e87>] dev_hard_start_xmit+0x307/0x660
[<c079bb71>] sch_direct_xmit+0xa1/0x1e0
[<c0784bb3>] dev_queue_xmit+0x183/0x730
[<c078c27a>] neigh_resolve_output+0xfa/0x1e0
[<c07b436a>] ip_finish_output+0x24a/0x460
[<c07b4897>] ip_output+0xb7/0x100
[<c07b2d60>] ip_local_out+0x20/0x60
[<c07e01ff>] igmpv3_sendpack+0x4f/0x60
[<c07e108f>] igmp_ifc_timer_expire+0x29f/0x330
[<c04520fc>] run_timer_softirq+0x15c/0x2f0
[<c0449e3e>] __do_softirq+0xae/0x1e0
irq event stamp: 18380437
hardirqs last enabled at (18380437): [<c0526027>] __slab_alloc.clone.3+0x67/0x5f0
hardirqs last disabled at (18380436): [<c0525ff3>] __slab_alloc.clone.3+0x33/0x5f0
softirqs last enabled at (18377616): [<c0449eb3>] __do_softirq+0x123/0x1e0
softirqs last disabled at (18377611): [<c041278d>] do_softirq+0x9d/0xe0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&intf->seqlock)->rlock);
<Interrupt>
lock(&(&intf->seqlock)->rlock);
*** DEADLOCK ***
4 locks held by kworker/u:2/30374:
#0: (wiphy_name(local->hw.wiphy)){++++.+}, at: [<c045cf99>] process_one_work+0x109/0x3f0
#1: ((&sdata->work)){+.+.+.}, at: [<c045cf99>] process_one_work+0x109/0x3f0
#2: (&ifibss->mtx){+.+.+.}, at: [<f98f005b>] ieee80211_ibss_work+0x1b/0x470 [mac80211]
#3: (&intf->beacon_skb_mutex){+.+...}, at: [<f997a644>] rt2x00queue_update_beacon+0x24/0x50 [rt2x00lib]
stack backtrace:
Pid: 30374, comm: kworker/u:2 Not tainted 3.4.0-wl+ #4
Call Trace:
[<c04962a6>] print_usage_bug+0x1f6/0x220
[<c0496a12>] mark_lock+0x2c2/0x300
[<c0495ff0>] ? check_usage_forwards+0xc0/0xc0
[<c04978ec>] __lock_acquire+0x4bc/0x1050
[<c0527890>] ? __kmalloc_track_caller+0x1c0/0x1d0
[<c0777fb6>] ? copy_skb_header+0x26/0x90
[<c0498504>] lock_acquire+0x84/0xf0
[<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
[<c0835733>] _raw_spin_lock+0x33/0x40
[<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
[<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib]
[<f997a5cf>] rt2x00queue_update_beacon_locked+0x5f/0xb0 [rt2x00lib]
[<f997a64d>] rt2x00queue_update_beacon+0x2d/0x50 [rt2x00lib]
[<f9977e3a>] rt2x00mac_bss_info_changed+0x1ca/0x200 [rt2x00lib]
[<f9977c70>] ? rt2x00mac_remove_interface+0x70/0x70 [rt2x00lib]
[<f98e4dd0>] ieee80211_bss_info_change_notify+0xe0/0x1d0 [mac80211]
[<f98ef7b8>] __ieee80211_sta_join_ibss+0x3b8/0x610 [mac80211]
[<c0496ab4>] ? mark_held_locks+0x64/0xc0
[<c0440012>] ? virt_efi_query_capsule_caps+0x12/0x50
[<f98efb09>] ieee80211_sta_join_ibss+0xf9/0x140 [mac80211]
[<f98f0456>] ieee80211_ibss_work+0x416/0x470 [mac80211]
[<c0496d8b>] ? trace_hardirqs_on+0xb/0x10
[<c077683b>] ? skb_dequeue+0x4b/0x70
[<f98f207f>] ieee80211_iface_work+0x13f/0x230 [mac80211]
[<c045cf99>] ? process_one_work+0x109/0x3f0
[<c045d015>] process_one_work+0x185/0x3f0
[<c045cf99>] ? process_one_work+0x109/0x3f0
[<f98f1f40>] ? ieee80211_teardown_sdata+0xa0/0xa0 [mac80211]
[<c045ed86>] worker_thread+0x116/0x270
[<c045ec70>] ? manage_workers+0x1e0/0x1e0
[<c0462f64>] kthread+0x84/0x90
[<c0462ee0>] ? __init_kthread_worker+0x60/0x60
[<c083d382>] kernel_thread_helper+0x6/0x10
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2x00mac.c')
-rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00mac.c | 1 |
1 files changed, 0 insertions, 1 deletions
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; |