Commits
Stanislaw Gruszka committed e55b32c110b
rtlwifi: fix lps_lock deadlock
rtl_lps_leave can be called from interrupt context, so we have to
disable interrupts when taking lps_lock.
Below is full lockdep info about deadlock:
[ 93.815269] =================================
[ 93.815390] [ INFO: inconsistent lock state ]
[ 93.815472] 2.6.41.1-3.offch.fc15.x86_64.debug #1
[ 93.815556] ---------------------------------
[ 93.815635] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 93.815743] swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[ 93.815832] (&(&rtlpriv->locks.lps_lock)->rlock){+.?...}, at: [<ffffffffa025dad6>] rtl_lps_leave+0x26/0x103 [rtlwifi]
[ 93.815947] {SOFTIRQ-ON-W} state was registered at:
[ 93.815947] [<ffffffff8108e10d>] __lock_acquire+0x369/0xd0c
[ 93.815947] [<ffffffff8108efb3>] lock_acquire+0xf3/0x13e
[ 93.815947] [<ffffffff814e981d>] _raw_spin_lock+0x45/0x79
[ 93.815947] [<ffffffffa025de34>] rtl_swlps_rf_awake+0x5a/0x76 [rtlwifi]
[ 93.815947] [<ffffffffa025aec0>] rtl_op_config+0x12a/0x32a [rtlwifi]
[ 93.815947] [<ffffffffa01d614b>] ieee80211_hw_config+0x124/0x129 [mac80211]
[ 93.815947] [<ffffffffa01e0af3>] ieee80211_dynamic_ps_disable_work+0x32/0x47 [mac80211]
[ 93.815947] [<ffffffff81075aa5>] process_one_work+0x205/0x3e7
[ 93.815947] [<ffffffff81076753>] worker_thread+0xda/0x15d
[ 93.815947] [<ffffffff8107a119>] kthread+0xa8/0xb0
[ 93.815947] [<ffffffff814f3184>] kernel_thread_helper+0x4/0x10
[ 93.815947] irq event stamp: 547822
[ 93.815947] hardirqs last enabled at (547822): [<ffffffff814ea1a7>] _raw_spin_unlock_irqrestore+0x45/0x61
[ 93.815947] hardirqs last disabled at (547821): [<ffffffff814e9987>] _raw_spin_lock_irqsave+0x22/0x8e
[ 93.815947] softirqs last enabled at (547790): [<ffffffff810623ed>] _local_bh_enable+0x13/0x15
[ 93.815947] softirqs last disabled at (547791): [<ffffffff814f327c>] call_softirq+0x1c/0x30
[ 93.815947]
[ 93.815947] other info that might help us debug this:
[ 93.815947] Possible unsafe locking scenario:
[ 93.815947]
[ 93.815947] CPU0
[ 93.815947] ----
[ 93.815947] lock(&(&rtlpriv->locks.lps_lock)->rlock);
[ 93.815947] <Interrupt>
[ 93.815947] lock(&(&rtlpriv->locks.lps_lock)->rlock);
[ 93.815947]
[ 93.815947] *** DEADLOCK ***
[ 93.815947]
[ 93.815947] no locks held by swapper/0.
[ 93.815947]
[ 93.815947] stack backtrace:
[ 93.815947] Pid: 0, comm: swapper Not tainted 2.6.41.1-3.offch.fc15.x86_64.debug #1
[ 93.815947] Call Trace:
[ 93.815947] <IRQ> [<ffffffff814dfd00>] print_usage_bug+0x1e7/0x1f8
[ 93.815947] [<ffffffff8101a849>] ? save_stack_trace+0x2c/0x49
[ 93.815947] [<ffffffff8108d55c>] ? print_irq_inversion_bug.part.18+0x1a0/0x1a0
[ 93.815947] [<ffffffff8108dc8a>] mark_lock+0x106/0x220
[ 93.815947] [<ffffffff8108e099>] __lock_acquire+0x2f5/0xd0c
[ 93.815947] [<ffffffff810152af>] ? native_sched_clock+0x34/0x36
[ 93.830125] [<ffffffff810152ba>] ? sched_clock+0x9/0xd
[ 93.830125] [<ffffffff81080181>] ? sched_clock_local+0x12/0x75
[ 93.830125] [<ffffffffa025dad6>] ? rtl_lps_leave+0x26/0x103 [rtlwifi]
[ 93.830125] [<ffffffff8108efb3>] lock_acquire+0xf3/0x13e
[ 93.830125] [<ffffffffa025dad6>] ? rtl_lps_leave+0x26/0x103 [rtlwifi]
[ 93.830125] [<ffffffff814e981d>] _raw_spin_lock+0x45/0x79
[ 93.830125] [<ffffffffa025dad6>] ? rtl_lps_leave+0x26/0x103 [rtlwifi]
[ 93.830125] [<ffffffff81422467>] ? skb_dequeue+0x62/0x6d
[ 93.830125] [<ffffffffa025dad6>] rtl_lps_leave+0x26/0x103 [rtlwifi]
[ 93.830125] [<ffffffffa025f677>] _rtl_pci_ips_leave_tasklet+0xe/0x10 [rtlwifi]
[ 93.830125] [<ffffffff8106281f>] tasklet_action+0x8d/0xee
[ 93.830125] [<ffffffff810629ce>] __do_softirq+0x112/0x25a
[ 93.830125] [<ffffffff814f327c>] call_softirq+0x1c/0x30
[ 93.830125] [<ffffffff81010bf6>] do_softirq+0x4b/0xa1
[ 93.830125] [<ffffffff81062d7d>] irq_exit+0x5d/0xcf
[ 93.830125] [<ffffffff814f3b7e>] do_IRQ+0x8e/0xa5
[ 93.830125] [<ffffffff814ea533>] common_interrupt+0x73/0x73
[ 93.830125] <EOI> [<ffffffff8108b825>] ? trace_hardirqs_off+0xd/0xf
[ 93.830125] [<ffffffff812bb6d5>] ? intel_idle+0xe5/0x10c
[ 93.830125] [<ffffffff812bb6d1>] ? intel_idle+0xe1/0x10c
[ 93.830125] [<ffffffff813f8d5e>] cpuidle_idle_call+0x11c/0x1fe
[ 93.830125] [<ffffffff8100e2ef>] cpu_idle+0xab/0x101
[ 93.830125] [<ffffffff814c6373>] rest_init+0xd7/0xde
[ 93.830125] [<ffffffff814c629c>] ? csum_partial_copy_generic+0x16c/0x16c
[ 93.830125] [<ffffffff81d4bbb0>] start_kernel+0x3dd/0x3ea
[ 93.830125] [<ffffffff81d4b2c4>] x86_64_start_reservations+0xaf/0xb3
[ 93.830125] [<ffffffff81d4b140>] ? early_idt_handlers+0x140/0x140
[ 93.830125] [<ffffffff81d4b3ca>] x86_64_start_kernel+0x102/0x111
Resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=755154
Reported-by: vjain02@students.poly.edu
Reported-and-tested-by: Oliver Paukstadt <pstadt@sourcentral.org>
Cc: stable@vger.kernel.org
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>