linux-kernel - Re: question about concurrent regmap i2c usage

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Message-ID: <4929e112-9a08-8b9c-f64e-fd2ffaf8b45e@analog.com>
Date:   Wed, 5 Apr 2017 08:31:15 +0200
From:   Michael Hennerich <michael.hennerich@...log.com>
To:     Mark Brown <broonie@...nel.org>
CC:     <linus.walleij@...aro.org>, <wsa@...-dreams.de>,
        <linux-gpio@...r.kernel.org>, <linux-i2c@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: question about concurrent regmap i2c usage

On 04.04.2017 14:26, Mark Brown wrote:
> On Tue, Apr 04, 2017 at 10:28:23AM +0200, Michael Hennerich wrote:
>
>> A question came up, regarding whether it's recommended to mix regmap_i2c and
>> plain i2c_smbus or direct adapter transfers.
>
>> In this specific case for the i2c MUX portion we need to avoid double locks,
>> and therefore use un-locked direct adapter transfers.
>
>> The same time we also implement a small gpiochip, where we would like to use
>> regmap to avoid some boilerplate code for the register cache.
>
> That should work fine providing nothing tries to change cached registers
> underneath the regmap.  regmap won't be able to tell anything's changed
> otherwise.

Hi Mark,

Thanks for confirmation!

-- 
Greetings,
Michael

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