Date: Fri, 2 Apr 2010 18:27:05 +0200
From: Samuel Ortiz <sameo@linux.intel.com>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mfd: Improve WM831x AUXADC completion handling
Message-ID: <20100402162704.GM8010@sortiz.org>
References: <1270222263-14203-1-git-send-email-broonie@opensource.wolfsonmicro.com>
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On Fri, Apr 02, 2010 at 04:31:03PM +0100, Mark Brown wrote:
> Currently completion of WM831x AUXADC conversions is monitored by
> checking for convertor enable. Due to the mechanism used to ensure
> data corruption is avoided when reading AUXADC data there may under
> heavy I/O be a window where this bit has cleared but the conversion
> results have not been updated. Data availability is only guaranteed
> after the AUXADC data interrupt has been asserted.
> 
> Avoid this by always using the interrupt to detect completion. If the
> chip IRQ is not set up then we poll the IRQ status register for up to
> 5ms. If it is set up then we rely on the data done interrupt with a
> vastly increased timeout, failing the conversion if the interrupt is
> not generated.
> 
> This also saves a register read when using interrupts.
> 
> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Applied to my for-next branch, thanks.

Cheers,
Samuel.

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Intel Open Source Technology Centre
http://oss.intel.com/
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