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From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/6] arm: kconfig: don't select TWD with local timer for Armada 370/XP
Date: Tue, 22 Jan 2013 17:42:57 +0000	[thread overview]
Message-ID: <201301221742.57490.arnd@arndb.de> (raw)
In-Reply-To: <20130122171817.GM23505@n2100.arm.linux.org.uk>

On Tuesday 22 January 2013, Russell King - ARM Linux wrote:
> > 
> > > >       default y
> > > I am not a kconfig expert, but won't this line set HAVE_ARM_TWD to 'y' whatever
> > > the result of the previous line?
> > 
> > Yes, that was a mistake on my side.
> 
> Sigh.  No.  Wrong.
> 
> config HAVE_ARM_TWD
>         depends on LOCAL_TIMERS
>         default ARCH_MULTIPLATFORM || (!ARCH_MSM_SCORPIONMP && !EXYNOS4_MCT && !ARMADA_370_XP_TIMER)
>         default y
> 
> This takes the value of the first enabled default.  The first enabled
> default is the first default (it's unconditional).  So, the default y
> will never be used.

Right. I actually know how it works, but didn't think through it this
time. The 'default y' was a mistake on my side and should not have
been in there. I was also missing a 'bool' statement in there, which
makes the whole thing a syntax error.

> Given the above, it's far from clear what the actual behaviour being
> asked for is - it looks totally and utterly screwed to me - and the
> wrong thing to be doing.
> 
> If the desire is to have it enabled if ARCH_MULTIPLATFORM is set, then
> it's easy, and requires just a single line addition:
> 
>  config LOCAL_TIMERS
>         bool "Use local timer interrupts"
>         depends on SMP
>         default y
>         select HAVE_ARM_TWD if (!ARCH_MSM_SCORPIONMP && !EXYNOS4_MCT)
> +       select HAVE_ARM_TWD if ARCH_MULTIPLATFORM

Right. The effect would be the same as what I intended to write:

config LOCAL_TIMERS
        bool "Use local timer interrupts"
        depends on SMP
        default y

config HAVE_ARM_TWD
	def_bool ARCH_MULTIPLATFORM || (!ARCH_MSM_SCORPIONMP && !EXYNOS4_MCT)
        depends on LOCAL_TIMERS

but your patch is simpler.

	Arnd

  reply	other threads:[~2013-01-22 17:42 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-21 17:53 [PATCH 0/6] arm: mvebu: add support for local timer for Armada 370/XP Gregory CLEMENT
2013-01-21 17:53 ` [PATCH 1/6] arm: mvebu: Add support for local interrupt Gregory CLEMENT
2013-01-21 18:17   ` Thomas Petazzoni
2013-01-21 22:07     ` Gregory CLEMENT
2013-01-21 23:26       ` Ezequiel Garcia
2013-01-22  9:09         ` Gregory CLEMENT
2013-01-22 16:55           ` Thomas Petazzoni
2013-01-21 17:53 ` [PATCH 2/6] clocksource: time-armada-370-xp: add local timer support Gregory CLEMENT
2013-01-21 17:59   ` Russell King - ARM Linux
2013-01-21 18:04     ` Gregory CLEMENT
2013-01-23 13:11   ` Gregory CLEMENT
2013-01-21 17:53 ` [PATCH 3/6] arm: kconfig: don't select TWD with local timer for Armada 370/XP Gregory CLEMENT
2013-01-21 18:31   ` Arnd Bergmann
2013-01-21 19:29     ` Matt Sealey
2013-01-21 20:44       ` Arnd Bergmann
2013-01-22 17:12         ` Russell King - ARM Linux
2013-01-22 20:46         ` Rob Herring
2013-01-22 21:19           ` Arnd Bergmann
2013-01-21 22:37     ` Gregory CLEMENT
2013-01-22 15:57       ` Arnd Bergmann
2013-01-22 16:34         ` Gregory CLEMENT
2013-01-22 17:42           ` [PATCH] arm: kconfig: always select TWD with local timer for multiplatform Gregory CLEMENT
2013-01-22 17:18         ` [PATCH 3/6] arm: kconfig: don't select TWD with local timer for Armada 370/XP Russell King - ARM Linux
2013-01-22 17:42           ` Arnd Bergmann [this message]
2013-01-21 17:54 ` [PATCH 4/6] arm: mvebu: update defconfig with local timer support Gregory CLEMENT
2013-01-21 17:54 ` [PATCH 5/6] arm: mvebu: update DT to support local timers Gregory CLEMENT
2013-01-21 17:54 ` [PATCH 6/6] clocksource: update and move armada-370-xp-timer documentation to timer directory Gregory CLEMENT
2013-01-21 18:22   ` Arnd Bergmann
2013-01-21 22:05     ` Gregory CLEMENT
2013-01-21 22:26       ` Arnd Bergmann

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