Re: [rtc-linux] Re: [PATCH] rtc: Make rtc_update_irq callable with irqs enabled

From: Alessandro Zummo <alessandro.zummo@towertech.it>
To: rtc-linux@googlegroups.com
Cc: david-b@pacbell.net, Atsushi Nemoto <anemo@mba.ocn.ne.jp>,
	akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	hcegtvedt@atmel.com, vapier@gentoo.org,
	rongkai.zhan@windriver.com, balajirrao@openmoko.org,
	broonie@opensource.wolfsonmicro.com
Subject: Re: [rtc-linux] Re: [PATCH] rtc: Make rtc_update_irq callable with irqs enabled
Date: Thu, 23 Apr 2009 20:27:49 +0200	[thread overview]
Message-ID: <20090423202749.767ab73b@i1501.lan.towertech.it> (raw)
In-Reply-To: <200904231115.57525.david-b@pacbell.net>

On Thu, 23 Apr 2009 11:15:56 -0700
David Brownell <david-b@pacbell.net> wrote:

> On Thursday 23 April 2009, Alessandro Zummo wrote:
> >  Is not an API change, we are gradually relaxing it if it
> >  proves workable :)
> 
> Erm, it *is* an API change at least to the extent that
> the last version of the patch made the interface spec
> become incorrect.

 I know, I was just playing it down :)

> Current interface spec *requires* that function to be
> called with IRQs disabled.
> 
> The downside of that spec is that there's no way to test
> it, since CONFIG_LOCKDEP doesn't understand that almost
> all IRQ handlers don't disable IRQs.  So there are some
> bugs in RTC drivers that can only be uncovered by code
> review.

 That's was what I was proposing. I'll give a code review
 but will not be able to test every driver so I'll need
 help from the authors. 

 But first I need someone to validate the theory that
 says that we don't really need the IRQs to be disabled,
 as I stated in the email to Andrew.

 do you agree? :)

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it