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

-----Original Message-----
From: linux-omap-owner at vger.kernel.org 
[mailto:linux-omap-owner at vger.kernel.org] On Behalf Of Koen Kooi
Sent: Sunday, June 26, 2011 1:41 AM
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 25 jun 2011, om 20:51 heeft Premi, Sanjeev het volgende geschreven:

quoted

quoted

-----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:

quoted

quoted

quoted

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?

[sp] It was tested on BeagleXM RevB on top of linux-omap master - as
     on day of submitting th patch.

Especially on the 
boards affected by the capacitor issue on the external clock.--

[sp] The patch relies on the check for board revision to continue using
     GPTIMER12 on affected boards - which I am assuming to be right.

     I don't have access to any of these versions, trying to find some
     early users. Hope someone on the list with Ax/Bx version can share
     the result...

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