linux-kernel - Re: [PATCH 2/2] iio: imu: mpu6050: Add support for vdd-supply regulator

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Message-ID: <20191106213359.GA130672@gerhold.net>
Date:   Wed, 6 Nov 2019 22:36:16 +0100
From:   Stephan Gerhold <stephan@...hold.net>
To:     Jean-Baptiste Maneyrol <JManeyrol@...ensense.com>
Cc:     Jonathan Cameron <jic23@...nel.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Brian Masney <masneyb@...tation.org>,
        Jonathan Marek <jonathan@...ek.ca>,
        "linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] iio: imu: mpu6050: Add support for vdd-supply
 regulator

Hi JB,

On Wed, Nov 06, 2019 at 07:55:20PM +0000, Jean-Baptiste Maneyrol wrote:
> Hello Stephan,
> 
> nice patch but I have an important concern.
> 
> We are calling the core_enable/disable_regulator functions when going into suspend and resume.
> With your changes, we are going to power down the chip when going into suspend and then power it up again.
> This way we will loose all already set configuration, like FSR, sampling rate, init values, ...
> The chip will not be able to work correctly anymore after a suspend-resume cycle.
> 
> You need to change the resume/suspend handlers to only disable/enable the vddio regulator, not the vdd one.

That is a good point, thanks!
I guess we are not able to use the regulator bulk API in this case...

I will send a v2 soon.

Stephan