[PATCH] omap3: beagle: Use GPTIMERi 1 for clockevents

Jonathan Cameron jic23 at cam.ac.uk
Mon Jun 27 08:32:25 EDT 2011


On 06/25/11 21:10, Koen Kooi wrote:
> 
> Op 25 jun 2011, om 20:51 heeft Premi, Sanjeev het volgende geschreven:
> 
>>> -----Original Message-----
>>> From: linux-omap-owner at vger.kernel.org 
>>> [mailto:linux-omap-owner at vger.kernel.org] On Behalf Of Koen Kooi
>>> Sent: Saturday, June 25, 2011 1:47 PM
>>> To: linux-omap at vger.kernel.org List
>>> Cc: linux-arm-kernel; Paul Walmsley
>>> Subject: Re: [PATCH] omap3: beagle: Use GPTIMERi 1 for clockevents
>>>
>>>
>>> Op 24 jun 2011, om 18:23 heeft Sanjeev Premi het volgende geschreven:
>>>
>>>> The current selection of the GPTIMER on was result of
>>>> a hardware issue in early versions of the Beagleboards
>>>> (Ax and B1 thru B4). [1] [2]
>>>>
>>>> Its been long since the hardware issue has been fixed.
>>>> This patch uses GPTIMER 1 for all newer board revisions
>>>> incl. Beagleboard XM.
>>
>> [sp] I didn't include a reason - because the problem may not
>>     be reproducible on the public trees.
>>
>>     During tests performed in internal development trees, the
>>     BogoMIPS calculations @ 1GHz wouldn't go beyond "830-850"
>>     range. While there was no such inconsistency on OMAP3EVM.
>>
>>     After few days of debug GPTIMER12 came to be only difference.
>>     Tracing GPTIMER12 in the spec proved quite a challenge; the
>>     as timer is not included in the TRM and corresponding interrupt
>>     is marked reserved. Paul (in cc:) obviously had access to
>>     documents that we don't.
>>
>>     This patch is merely trying to bring parity in use of GPTIMER
>>     across OMAP3 boards (AND use documented IP) - taking note of
>>     many Beagleboards where current code is necessary.
> 

> I get a value of 1010 ±10 bogoMIPS consistently with .39 + dvfs
> patches. Having said that, this patch does seem to be an improvement,
> but has it actually been tested on real beagleboard hardware with a
> recent kernel? Especially on the boards affected by the capacitor
> issue on the external clock.--
Hi Koen,

Probably obvious to anyone else here, but which dvfs patches?

I've only recently acquired an xm and hence wasn't following these threads.
Don't suppose you could point me to a tree with them in or the relevant
thread?

Cheers,

Jonathan




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