From: Linus Torvalds Date: Wed, 22 Nov 2006 17:32:06 +0000 (-0800) Subject: Don't call "note_interrupt()" with irq descriptor lock held X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b42172fc7b569a0ef2b0fa38d71382969074c0e2;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git Don't call "note_interrupt()" with irq descriptor lock held This reverts commit f72fa707604c015a6625e80f269506032d5430dc, and solves the problem that it tried to fix by simply making "__do_IRQ()" call the note_interrupt() function without the lock held, the way everybody else does. It should be noted that all interrupt handling code must never allow the descriptor actors to be entered "recursively" (that's why we do all the magic IRQ_PENDING stuff in the first place), so there actually is exclusion at that much higher level, even in the absense of locking. Acked-by: Vivek Goyal Acked-by:Pavel Emelianov Cc: Andrew Morton Cc: Ingo Molnar Cc: Adrian Bunk Signed-off-by: Linus Torvalds --- diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 42aa6f1a3f0f..a681912bc89a 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -231,10 +231,10 @@ fastcall unsigned int __do_IRQ(unsigned int irq) spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); - - spin_lock(&desc->lock); if (!noirqdebug) note_interrupt(irq, desc, action_ret); + + spin_lock(&desc->lock); if (likely(!(desc->status & IRQ_PENDING))) break; desc->status &= ~IRQ_PENDING; diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 9c7e2e4c1fe7..543ea2e5ad93 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -147,11 +147,7 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, if (unlikely(irqfixup)) { /* Don't punish working computers */ if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) { - int ok; - - spin_unlock(&desc->lock); - ok = misrouted_irq(irq); - spin_lock(&desc->lock); + int ok = misrouted_irq(irq); if (action_ret == IRQ_NONE) desc->irqs_unhandled -= ok; }