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Subject: Re: [PATCH v1 4/6] ASoC: codecs: msm8916-wcd-analog: set default
 micbias voltage to 1.8
To: Mark Brown <broonie@kernel.org>
Cc: Banajit Goswami <bgoswami@codeaurora.org>, alsa-devel@alsa-project.org,
        Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
        Patrick Lai <plai@codeaurora.org>, linux-kernel@vger.kernel.org
References: <20170726003512.18965-1-srinivas.kandagatla@linaro.org>
 <20170726003512.18965-5-srinivas.kandagatla@linaro.org>
 <20170728134038.y5wnrurmwn4bxxsh@sirena.org.uk>
 <94765031-d840-bcae-11e3-16e1e55a7aa7@linaro.org>
 <20170728140108.ds5x4irfep4ss3lv@sirena.org.uk>
From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <0f96d65a-f7d9-0139-e0c4-49069e717f34@linaro.org>
Date: Fri, 28 Jul 2017 15:45:08 +0100
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On 28/07/17 15:01, Mark Brown wrote:
> On Fri, Jul 28, 2017 at 02:54:59PM +0100, Srinivas Kandagatla wrote:
>> On 28/07/17 14:40, Mark Brown wrote:
>>> On Wed, Jul 26, 2017 at 02:35:10AM +0200, srinivas.kandagatla@linaro.org wrote:
>>>> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
>>>> This patch sets the default internal micbias voltage to 1.8v. This
>>>> default value is required for mbhc buttons to work. Also adds dt
>>>> bindings to allow the board level file to specify the required default
>>>> micbias value.
> 
>>> What was the default previously?
> 
>> This was set to 2.7v previously for special headsets which have high
>> impedance.
> 
> So obviously this will break existing users.  That's not OK.

This would not break any exiting users, as this part is applicable for 
only headset detect usecase. I will try to address this in ("PATCH 5/6 
ASoC: codecs: msm8916-wcd-analog: add MBHC support") patch.

The default voltage for most common usecase should be set to 1.8v anyway.