Message-ID: <558B17F7.8070401@gmx.de>
Date: Wed, 24 Jun 2015 22:49:59 +0200
From: Sergej Sawazki <ce3a@gmx.de>
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To: Mark Brown <broonie@kernel.org>
CC: gregkh@linuxfoundation.org, wsa@the-dreams.de,
        linux-kernel@vger.kernel.org
Subject: Re: [BUG ?] regmap: debugfs: WARN_ON at regmap-debugfs.c:151
References: <557C2E3E.80000@gmx.de> <20150615094922.GB18309@sirena.org.uk> <B1FC1740-086A-4869-9D97-88B0B742EDE8@gmx.de> <20150615144933.GO18309@sirena.org.uk>
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On Mon, 15 Jun 2015 15:49:33 +0100, Mark Brown wrote:
> On Mon, Jun 15, 2015 at 02:42:30PM +0200, Sergej Sawazki wrote:
>> Am 15. Juni 2015 11:49:22 MESZ, schrieb Mark Brown <broonie@kernel.org>:
>
>>> We need to change that code to special case write only register maps
>>> like this and just skip having a cache for those devices.  They
>>> normally
>>> have very small register maps anyway so it shouldn't have too big an
>>> impact on performance.
>
>> I'm having this issue with a wm8741 DAC, its register map is not
>> "write only", it has readable and writeable registers.
>
> Are you *sure* there are physically readable registers on the device?
> It's difficult to implement for 7x9 devices given that the top register
> bit is in the byte used to send the register address, I expect you'll
> find that the registers marked as readable are actually those that
> should be cached.
>

You are right, the registers are not physically readable. Sorry for the
confusion.

What I actually was trying to do is to read the cached register values.

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