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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: ARM: 7653/2: do not scale loops_per_jiffy when using a constant delay clock
Date: Wed, 6 Mar 2013 02:23:08 +0000	[thread overview]
Message-ID: <20130306022308.GA21539@mudshark.cambridge.arm.com> (raw)

Hi Nico,

I notice that commit 70264367a243 ("ARM: 7653/2: do not scale loops_per_jiffy
when using a constant delay clock") is in mainline, but I'm not sure whether
it's the right fix. Unfortunately, I failed to find it in the list archives,
so I couldn't repy to the original patch.

It seems like a better fix would be to pass the CPUFREQ_CONST_LOOPS flag from
the cpufreq driver doing the frequency scaling, which would prevent
loops_per_jiffy from being scaled at all. It also means that UP platforms
would work correctly, while I think they're still broken with your patch.

What do you reckon? I'm trying to do some cleanup in this area with the aim
of making the core cpufreq driver SMP-aware.

Cheers,

Will

             reply	other threads:[~2013-03-06  2:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-06  2:23 Will Deacon [this message]
2013-03-06 18:37 ` ARM: 7653/2: do not scale loops_per_jiffy when using a constant delay clock Russell King - ARM Linux
2013-03-07  3:32   ` Will Deacon
2013-03-07  6:37     ` Nicolas Pitre
2013-03-19 18:16       ` Will Deacon
2013-03-19 19:00         ` Nicolas Pitre
2013-03-07  9:22     ` Russell King - ARM Linux

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