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From: Eric Miao <eric.y.miao@gmail.com>
To: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>,
	LKML <linux-kernel@vger.kernel.org>,
	Mark Brown <broonie@sirena.org.uk>,
	mike.rapoport@gmail.com, Paul Shen <bshen9@marvell.com>,
	Haojian Zhuang <hzhuang1@marvell.com>
Subject: Re: da9030: ldo11 ignores disable
Date: Tue, 14 Jul 2009 23:17:34 +0800	[thread overview]
Message-ID: <4A5CA18E.70903@gmail.com> (raw)
In-Reply-To: <4A4DB73A.9050803@gmail.com>

Eric Miao wrote:
> Jonathan Cameron wrote:
>> Liam Girdwood wrote:
>>> On Thu, 2009-06-25 at 15:39 +0000, Jonathan Cameron wrote:
>>>> Hi All,
>>>>
>>>> Whilst testing a regulator machine config I've run into a weird issue.
>>>>
>>>> The preliminary data sheet I have suggests that there are two enable
>>>> registers
>>>> for ldo11 but neither rctl22 or rctl11 seems to have any effect (on
>>>> their own
>>>> or both cleared together). I can change the voltage just fine, but not
>>>> actually turn it off.
>>>>
>>>> Anyone come across this problem or have any idea what is going on?
>>> I've come across something similar in the past with two enable bits
>>> causing I2C register cache coherency issues. The cache bits became out
>>> of sync with reality and stopped some I2C writes happening.
>> Don't thing that could happen here.
>>> Another option is that your hardware config doesn't allow ldo11 to be
>>> disabled ?
>> Other than the obvious possibility that the hardware has a bug, I can't
>> seem to find a reason why this shouldn't work.
>>
> 
> I didn't meet this problem, Haojian & Paul, ever had this problem before?
> Or try lookup the Errata for the Arava chip.

Hi Jonathan,

Here's a hint, check register 0x1b - which looks suspicious to me to have
some side effects to LDO11.

  reply	other threads:[~2009-07-14 15:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-25 15:39 da9030: ldo11 ignores disable Jonathan Cameron
2009-06-26  9:44 ` Liam Girdwood
2009-06-26 10:17   ` Jonathan Cameron
2009-07-03  7:46     ` Eric Miao
2009-07-14 15:17       ` Eric Miao [this message]
2009-07-14 15:34         ` Jonathan Cameron

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