Messages in this thread Patch in this message | | | Date | Tue, 3 Nov 2009 08:45:32 -0500 | From | Prarit Bhargava <> | Subject | [PATCH]: use spin_lock_irqsave in try_one_irq() |
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(Prarit: Second try at this one, not sure if this made it to LKML or not. Sending to a wider audience this time)
Booting 2.6.32-rc5 on some IBM systems results in
Disabling IRQ #19
================================= [ INFO: inconsistent lock state ] 2.6.32-rc5 #1 --------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138 {IN-HARDIRQ-W} state was registered at: [<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d [<ffffffff814cdadd>] _spin_lock+0x40/0x89 [<ffffffff810c3389>] handle_level_irq+0x30/0x105 [<ffffffff81014e0e>] handle_irq+0x95/0xb7 [<ffffffff810141bd>] do_IRQ+0x6a/0xe0 [<ffffffff81012813>] ret_from_intr+0x0/0x16 irq event stamp: 195096 hardirqs last enabled at (195096): [<ffffffff814cd7f7>] _spin_unlock_irq+0x3a/0x5c hardirqs last disabled at (195095): [<ffffffff814cdbdd>] _spin_lock_irq+0x29/0x95 softirqs last enabled at (195088): [<ffffffff81068c92>] __do_softirq+0x1c1/0x1ef softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30 other info that might help us debug this: 1 lock held by swapper/0: #0: (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>] run_timer_softirq+0x1a9/0x315
stack backtrace: Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1 Call Trace: <IRQ> [<ffffffff81093e94>] valid_state+0x187/0x1ae [<ffffffff81096c7b>] ? check_usage_backwards+0x0/0xa3 [<ffffffff81093fe4>] mark_lock+0x129/0x253 [<ffffffff810951d4>] __lock_acquire+0x370/0xd5d [<ffffffff810c264e>] ? try_one_irq+0x32/0x138 [<ffffffff8109329d>] ? save_trace+0x4e/0xcd [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d [<ffffffff810c264e>] ? try_one_irq+0x32/0x138 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138 [<ffffffff814cdadd>] _spin_lock+0x40/0x89 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138 [<ffffffff810c264e>] try_one_irq+0x32/0x138 [<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d [<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49 [<ffffffff81070d82>] run_timer_softirq+0x239/0x315 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315 [<ffffffff810c27c1>] ? poll_spurious_irqs+0x0/0x49 [<ffffffff81068bd3>] __do_softirq+0x102/0x1ef [<ffffffff8108eccf>] ? tick_dev_program_event+0x46/0xcc [<ffffffff8101304c>] call_softirq+0x1c/0x30 [<ffffffff81014b65>] do_softirq+0x59/0xca [<ffffffff810686ad>] irq_exit+0x58/0xae [<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba [<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20 <EOI> [<ffffffff8101a7b5>] ? mwait_idle+0x8c/0xb5 [<ffffffff8101a7ac>] ? mwait_idle+0x83/0xb5 [<ffffffff81010e55>] ? cpu_idle+0xbe/0x100 [<ffffffff814c4270>] ? start_secondary+0x219/0x270
This happens because the &desc->lock is taken with spin_lock_irqsave and just a spin_lock. In the try_one_irq(), this lock really should be a spin_lock_irqsave().
I have not yet narrowed down the reason for the spurious interrupt (although I suspect it maybe to do with the radeon driver).
Successfully tested by me.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
--- linux-2.6.31.x86_64.orig/kernel/irq/spurious.c 2009-09-09 18:13:59.000000000 -0400 +++ linux-2.6.31.x86_64/kernel/irq/spurious.c 2009-10-26 10:55:56.709845786 -0400 @@ -27,8 +27,9 @@ static int try_one_irq(int irq, struct i { struct irqaction *action; int ok = 0, work = 0; + unsigned long flags; - spin_lock(&desc->lock); + spin_lock_irqsave(&desc->lock, flags); /* Already running on another processor */ if (desc->status & IRQ_INPROGRESS) { /* @@ -37,13 +38,13 @@ static int try_one_irq(int irq, struct i */ if (desc->action && (desc->action->flags & IRQF_SHARED)) desc->status |= IRQ_PENDING; - spin_unlock(&desc->lock); + spin_unlock_irqrestore(&desc->lock, flags); return ok; } /* Honour the normal IRQ locking */ desc->status |= IRQ_INPROGRESS; action = desc->action; - spin_unlock(&desc->lock); + spin_unlock_irqrestore(&desc->lock, flags); while (action) { /* Only shared IRQ handlers are safe to call */ @@ -56,7 +57,7 @@ static int try_one_irq(int irq, struct i } local_irq_disable(); /* Now clean up the flags */ - spin_lock(&desc->lock); + spin_lock_irqsave(&desc->lock, flags); action = desc->action; /* @@ -68,9 +69,9 @@ static int try_one_irq(int irq, struct i * Perform real IRQ processing for the IRQ we deferred */ work = 1; - spin_unlock(&desc->lock); + spin_unlock_irqrestore(&desc->lock, flags); handle_IRQ_event(irq, action); - spin_lock(&desc->lock); + spin_lock_irqsave(&desc->lock, flags); desc->status &= ~IRQ_PENDING; } desc->status &= ~IRQ_INPROGRESS; @@ -80,7 +81,7 @@ static int try_one_irq(int irq, struct i */ if (work && desc->chip && desc->chip->end) desc->chip->end(irq); - spin_unlock(&desc->lock); + spin_unlock_irqrestore(&desc->lock, flags); return ok; }
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