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From: skannan@codeaurora.org (Saravana Kannan)
To: linux-arm-kernel@lists.infradead.org
Subject: udelay() broken for SMP cores?
Date: Tue, 20 Apr 2010 23:43:23 -0700	[thread overview]
Message-ID: <4BCE9E8B.2070103@codeaurora.org> (raw)
In-Reply-To: <EAF47CD23C76F840A9E7FCE10091EFAB02C4FEED81@dbde02.ent.ti.com>


>> I looked at arch/arm/lib/delay.S and it looks like __udelay and
>> __const_udelay won't work correctly for SMP cores. The code just uses
>> the loops_per_jiffy variable instead of the per-CPU loops per jiffy data.
>>
>> Is anyone already working on a fix for that? If not, I can fix it up in
>> a way that's hopefully palatable to the community.
> 

> If you have case where individual CPUs are running at different speed and different
> Tick rate then only this can make difference.

Yes. I was talking about the case where the CPUs could be running at 
different speeds.

Thanks,
Saravana

  reply	other threads:[~2010-04-21  6:43 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-21  2:19 udelay() broken for SMP cores? Saravana Kannan
2010-04-21  4:56 ` Shilimkar, Santosh
2010-04-21  6:43   ` Saravana Kannan [this message]
2010-04-21  7:22     ` Russell King - ARM Linux
2010-04-21  9:39       ` skannan at codeaurora.org
2010-04-21  9:50         ` Russell King - ARM Linux
2010-04-21  9:58           ` Gilles Chanteperdrix
2010-04-21 10:00           ` Jamie Lokier
2010-04-21 19:29             ` Russell King - ARM Linux
2010-04-21 19:52               ` Jamie Lokier
2010-04-21 20:21                 ` Russell King - ARM Linux
2010-04-21 20:47                   ` Jamie Lokier
2010-04-21 20:57                     ` Russell King - ARM Linux
2010-04-22  0:14                       ` Jamie Lokier
2011-01-08 23:24                         ` Russell King - ARM Linux
2010-04-21 10:31           ` skannan at codeaurora.org
2010-04-21 19:33             ` Russell King - ARM Linux
2010-04-21 23:47               ` Saravana Kannan
2010-04-21 23:47                 ` Saravana Kannan
2010-04-23  9:00           ` Pavel Machek

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