Date: Mon, 30 Nov 2009 15:24:40 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
cc: =?ISO-8859-15?Q?Uwe_Kleine-K=F6nig?= 
	<u.kleine-koenig@pengutronix.de>,
       LKML <linux-kernel@vger.kernel.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>,
       David Brownell <dbrownell@users.sourceforge.net>,
       Andrew Morton <akpm@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>,
       Nicolas Pitre <nico@marvell.com>, Eric Miao <eric.y.miao@gmail.com>,
       John Stultz <johnstul@us.ibm.com>,
       Rusty Russell <rusty@rustcorp.com.au>, Remy Bohmer <linux@bohmer.net>,
       Hugh Dickins <hugh.dickins@tiscali.co.uk>,
       Andrea Gallo <andrea.gallo@stericsson.com>,
       Jamie Lokier <jamie@shareable.org>,
       linux-arm-kernel@lists.infradead.org,
       Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: Get rid of IRQF_DISABLED - (was [PATCH] genirq: warn about
 IRQF_SHARED|IRQF_DISABLED)
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On Mon, 30 Nov 2009, Peter Zijlstra wrote:
> On Mon, 2009-11-30 at 14:54 +0100, Thomas Gleixner wrote:
> > The correct solution IMNSHO is to get rid of IRQF_DISABLED and run
> > interrupt handlers always with interrupts disabled and require them
> > not to reenable interrupts themself.
> > 
> > Thoughts ?
> 
> I'm all for removing that brain damage:
> 
>   http://lkml.org/lkml/2009/3/2/33

Darn, I knew that we discussed that before, but my memory tricked me
into believing that it was years ago :)

> We should convert the broken hardware PIO and 3com interrupt things to
> threaded interrupts, and simply mandate all IRQ handlers run short and
> with IRQs disabled.

The ide stuff seems to be the only one which uses
local_irq_enable_in_hardirq() so that at least it tripped over lockdep
already.

What's the 3com wreckage about ?

> Except I guess that will upset some of the IRQ priority folks, like
> power, where they (iirc) have a stack per irq prio level.

Is that actually used ? Ben ?
 
> But its not like the core kernel knows about these nesting rules and can
> actually track any of that muck.

True.

	tglx
 
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