Bug in "genirq: record trigger type"

[Ingo Molnar]

* Yinghai Lu <yinghai at kernel.org> wrote:

> On Mon, Oct 20, 2008 at 11:32 PM, Benjamin Herrenschmidt
> <benh at kernel.crashing.org> wrote:
> > On Mon, 2008-10-20 at 22:05 +0000, Linux Kernel Mailing List wrote:
> >> Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0c5d1eb77a8be917b638344a22afe1398236482b
> >> Commit:     0c5d1eb77a8be917b638344a22afe1398236482b
> >> Parent:     d6d5aeb661fc14655c417f3582ae7ec52985d2a8
> >> Author:     David Brownell <dbrownell at users.sourceforge.net>
> >> AuthorDate: Wed Oct 1 14:46:18 2008 -0700
> >> Committer:  Ingo Molnar <mingo at elte.hu>
> >> CommitDate: Thu Oct 2 10:24:09 2008 +0200
> >
> > This one is obviously broken and breaks booting on a whole bunch of
> > machines (including powermac's and thus my G5, it's never good when my
> > own machine breaks !).
> >
> > Nice to see 3 SOB's and one Ack and nobody caught the obvious bug :-)
> >
> >>       desc = irq_desc + irq;
> >> -     if (desc->chip->set_type) {
> >> -             spin_lock_irqsave(&desc->lock, flags);
> >> -             ret = desc->chip->set_type(irq, type);
> >> -             spin_unlock_irqrestore(&desc->lock, flags);
> >> -     }
> >> +     if (type == IRQ_TYPE_NONE)
> >> +             return 0;
> >> +
> >> +     spin_lock_irqsave(&desc->lock, flags);
> >> +     ret = __irq_set_trigger(desc, irq, flags);
> >                                             ^^^^ type maybe ?
> >
> >> +     spin_unlock_irqrestore(&desc->lock, flags);
> >>       return ret;
> >>  }
> >
> > I have to run so no patch until tomorrow unless somebody beats me to it.
> 
> there is patch about it, but somehow get lost.

should be all sorted now, the fix is below.

	Ingo

------------------>
>From aac4ddd11a8d0e402ddc3fbc75204cb64efa0aac Mon Sep 17 00:00:00 2001
From: Chris Friesen <cfriesen at nortel.com>
Date: Mon, 20 Oct 2008 12:41:58 -0600
Subject: [PATCH] genirq: fix set_irq_type() when recording trigger type

In set_irq_type() we want to pass the type rather than the current
interrupt state.

Signed-off-by: Chris Friesen <cfriesen at nortel.com>
Signed-off-by: Ingo Molnar <mingo at elte.hu>
---
 kernel/irq/chip.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 4895fde..3de6ea3 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -127,7 +127,7 @@ int set_irq_type(unsigned int irq, unsigned int type)
 		return 0;
 
 	spin_lock_irqsave(&desc->lock, flags);
-	ret = __irq_set_trigger(desc, irq, flags);
+	ret = __irq_set_trigger(desc, irq, type);
 	spin_unlock_irqrestore(&desc->lock, flags);
 	return ret;
 }