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Date:   Wed, 11 Dec 2019 08:27:21 +0100
From:   Marco Felsch <m.felsch@pengutronix.de>
To:     Anson Huang <anson.huang@nxp.com>
Cc:     Leonard Crestez <leonard.crestez@nxp.com>,
        "shawnguo@kernel.org" <shawnguo@kernel.org>,
        "mark.rutland@arm.com" <mark.rutland@arm.com>,
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        "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
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        <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/3] ARM: dts: imx6ul-14x14-evk: Add sensors' GPIO
 regulator
Message-ID: <20191211072721.ze6yn2felxyae5eb@pengutronix.de>
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On 19-12-11 01:06, Anson Huang wrote:
> 
> 
> > Subject: Re: [PATCH 1/3] ARM: dts: imx6ul-14x14-evk: Add sensors' GPIO
> > regulator
> > 
> > On 24.10.2019 11:51, Anson Huang wrote:
> > > On i.MX6UL 14x14 EVK board, sensors' power are controlled by
> > > GPIO5_IO02, add GPIO regulator for sensors to manage their power.
> > >
> > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > 
> > For me this breaks network boot on imx6ul evk, relevant log snippet is this:
> > 
> >      fec 20b4000.ethernet eth0: Unable to connect to phy
> >      IP-Config: Failed to open eth0
> > 
> > Looking at schematics (SPF-28616_C2.pdf) I see that SNVS_TAMPER2 pin is
> > connected to PERI_PWREN which controls VPERI_3V3 which is used across
> > the board:
> >   * Sensors (VSENSOR_3V3)
> >   * Ethernet (VENET_3V3)
> >   * Bluetooth
> >   * CAN
> >   * Arduino header
> >   * Camera
> > 
> > Maybe there are board revision differences? As far as I can tell this regulator
> > is not specific to sensors so it should be always on.
> 
> You are correct, this regulator controls many other peripherals, I should make it always ON for now
> to make sure NOT break other peripheral, and after all other peripherals controlled
> by this regulator have added this regulator management, then the always ON can be
> removed.

IMHO marking the regulator as always on shouldn't be the fix. Is it to
much work to add all required regulators? At least please add a comment
which describes the need of the always-on property.

Regards,
  Marco 

> Thanks,
> Anson

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