From: anarsoul@gmail•com (Vasily Khoruzhick)
To: linux-arm-kernel@lists•infradead.org
Subject: PXA270 Random Hangs at Low Core Freq
Date: Fri, 4 Mar 2011 20:51:47 +0200 [thread overview]
Message-ID: <201103042051.47553.anarsoul@gmail.com> (raw)
In-Reply-To: <8C145DA2-AEF8-42AC-A4FB-C93003808D8C@prograde.net>
On Friday 04 March 2011 20:42:17 Michael Cashwell wrote:
> Hi Vasily,
>
> Thanks for the info. The curious thing is that
> arch/arm/mach-pxa/cpufreq-pxa2xx.c has a data table called pxa27x_freqs[]
> that seems to have FASTBUS set to true for all frequencies. So if CPUFREQ
> is enabled (which I do to save power) the kernel will enable FASTBUS even
> if the boot loader does not.
Yep, cpufreq was unstable on Zipit Z2, but after fixing pxa27x_freqs table to
disable fastbus bit it works OK.
> The boot loader would control that feature only if CPUFREQ were turned off
> (either in the config or dynamically). Is that the case you mean? If you
> are not using CPUFREQ in Linux what fixed frequency are you running?
>
> What I've ultimately done is comment out all the lower frequencies. If it
> only switches between 416, 520 and 624 MHz it works fine. It only hangs
> for me if I also allow the lower frequencies, and interestingly, the lower
> I allow the sooner the hang happens. It's unfortunate since the lower
> frequencies would save more power but I simply cannot make them work
> reliably.
Can you check if lower freqs work for you with fastbit not set?
> I've still not been able to identify why this happens (largely since JTAG
> becomes unresponsive) or find any published errata that I'm not accounting
> for.
Maybe this errata is not documented yet? :)
> -Mike
Regards
Vasily
next prev parent reply other threads:[~2011-03-04 18:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-18 17:38 PXA270 Random Hangs at Low Core Freq Michael Cashwell
2010-10-22 0:22 ` Marek Vasut
2010-10-22 8:41 ` Haojian Zhuang
2010-10-25 19:02 ` Michael Cashwell
2010-10-25 19:22 ` Eric Miao
2010-10-26 0:05 ` Haojian Zhuang
2010-10-26 17:06 ` Michael Cashwell
2011-02-03 12:04 ` Vasily Khoruzhick
2011-02-03 12:52 ` Michael Cashwell
2011-03-04 16:16 ` Vasily Khoruzhick
2011-03-04 18:42 ` Michael Cashwell
2011-03-04 18:51 ` Vasily Khoruzhick [this message]
2011-03-30 11:45 ` Michael Cashwell
2010-11-10 13:54 ` Pavel Machek
2010-10-25 19:46 ` Marek Vasut
2010-10-25 20:53 ` Michael Cashwell
2010-10-26 14:47 ` Marek Vasut
2010-12-03 20:20 ` Robert Jarzmik
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