From: Leonard Crestez <leonard.crestez@nxp.com>
To: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org, Anson Huang <Anson.Huang@nxp.com>,
Irina Tirdea <irina.tirdea@nxp.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
linux-pm@vger.kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Liam Girdwood <lgirdwood@gmail.com>,
linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
Octavian Purdila <octavian.purdila@nxp.com>,
Sascha Hauer <kernel@pengutronix.de>,
Fabio Estevam <fabio.estevam@nxp.com>,
Robin Gong <yibin.gong@nxp.com>, Shawn Guo <shawnguo@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC 5/8] regulator: anatop: fix min dropout for bypass mode
Date: Tue, 28 Mar 2017 14:52:46 +0300 [thread overview]
Message-ID: <1490701966.3546.24.camel@nxp.com> (raw)
In-Reply-To: <20170324125438.5wy3r2mr3g5eaxvy@sirena.org.uk>
On Fri, 2017-03-24 at 12:54 +0000, Mark Brown wrote:
> On Wed, Mar 22, 2017 at 06:53:07PM +0200, Leonard Crestez wrote:
> > + if (anatop_reg->bypass)
> > + anatop_reg->rdesc.min_dropout_uV = 0;
> > + else
> > + anatop_reg->rdesc.min_dropout_uV = LDO_MIN_DROPOUT_UV;
> No, this is completely broken - you can't expect to randomly change hthe
> regulator description at runtime behind the back of the framework and
> expect things to work. If there is a need to do this we need an
> interface for getting the current value and a way to notify of changes.
>
> That said I would not expect the dropout voltage to be considered at
> all when the regulator is bypassed, since the regulator is not
> regulating it doesn't need any headroom.
It's a more complex solution but this could be handled in the core instead.
Basically the core would treat min_dropout_uV as zero if the regulator is
currently in bypass mode.
In theory a function could be added in regulator_ops to ask a regulator driver
what requirements it has for its supply but this does not seem necessary.
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WARNING: multiple messages have this Message-ID (diff)
From: leonard.crestez@nxp.com (Leonard Crestez)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 5/8] regulator: anatop: fix min dropout for bypass mode
Date: Tue, 28 Mar 2017 14:52:46 +0300 [thread overview]
Message-ID: <1490701966.3546.24.camel@nxp.com> (raw)
In-Reply-To: <20170324125438.5wy3r2mr3g5eaxvy@sirena.org.uk>
On Fri, 2017-03-24 at 12:54 +0000, Mark Brown wrote:
> On Wed, Mar 22, 2017 at 06:53:07PM +0200, Leonard Crestez wrote:
> > + if (anatop_reg->bypass)
> > + anatop_reg->rdesc.min_dropout_uV = 0;
> > + else
> > + anatop_reg->rdesc.min_dropout_uV = LDO_MIN_DROPOUT_UV;
> No, this is completely broken - you can't expect to randomly change hthe
> regulator description at runtime behind the back of the framework and
> expect things to work.??If there is a need to do this we need an
> interface for getting the current value and a way to notify of changes.
>
> That said I would not expect the dropout voltage to be considered at
> all when the regulator is bypassed, since the regulator is not
> regulating it doesn't need any headroom.
It's a more complex solution but this could be handled in the core instead.
Basically the core would treat min_dropout_uV as zero if the regulator is
currently in bypass mode.
In theory a function could be added in regulator_ops to ask a regulator driver
what requirements it has for its supply but this does not seem necessary.
WARNING: multiple messages have this Message-ID (diff)
From: Leonard Crestez <leonard.crestez@nxp.com>
To: Mark Brown <broonie@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
"Shawn Guo" <shawnguo@kernel.org>,
Sascha Hauer <kernel@pengutronix.de>,
Robin Gong <yibin.gong@nxp.com>,
Anson Huang <Anson.Huang@nxp.com>,
Irina Tirdea <irina.tirdea@nxp.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Fabio Estevam <fabio.estevam@nxp.com>,
"Octavian Purdila" <octavian.purdila@nxp.com>,
<linux-pm@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [RFC 5/8] regulator: anatop: fix min dropout for bypass mode
Date: Tue, 28 Mar 2017 14:52:46 +0300 [thread overview]
Message-ID: <1490701966.3546.24.camel@nxp.com> (raw)
In-Reply-To: <20170324125438.5wy3r2mr3g5eaxvy@sirena.org.uk>
On Fri, 2017-03-24 at 12:54 +0000, Mark Brown wrote:
> On Wed, Mar 22, 2017 at 06:53:07PM +0200, Leonard Crestez wrote:
> > + if (anatop_reg->bypass)
> > + anatop_reg->rdesc.min_dropout_uV = 0;
> > + else
> > + anatop_reg->rdesc.min_dropout_uV = LDO_MIN_DROPOUT_UV;
> No, this is completely broken - you can't expect to randomly change hthe
> regulator description at runtime behind the back of the framework and
> expect things to work. If there is a need to do this we need an
> interface for getting the current value and a way to notify of changes.
>
> That said I would not expect the dropout voltage to be considered at
> all when the regulator is bypassed, since the regulator is not
> regulating it doesn't need any headroom.
It's a more complex solution but this could be handled in the core instead.
Basically the core would treat min_dropout_uV as zero if the regulator is
currently in bypass mode.
In theory a function could be added in regulator_ops to ask a regulator driver
what requirements it has for its supply but this does not seem necessary.
next prev parent reply other threads:[~2017-03-28 11:52 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-22 16:53 [RFC 0/8] ARM: imx: Upstream fsl,ldo-bypass Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` [RFC 1/8] ARM: imx: gpc: Do not print error message for EPROBE_DEFER Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` [RFC 2/8] cpufreq: imx6q: Fix handling EPROBE_DEFER from regulator Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
[not found] ` <7f2618363d43b30db29f5f8ae822df413392f99d.1490199005.git.leonard.crestez-3arQi8VN3Tc@public.gmane.org>
2017-03-23 4:33 ` Viresh Kumar
2017-03-23 4:33 ` Viresh Kumar
2017-03-23 4:33 ` Viresh Kumar
2017-03-22 16:53 ` [RFC 3/8] cpufreq: imx6q: Set max suspend_freq to avoid changes during suspend Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-23 4:34 ` Viresh Kumar
2017-03-23 4:34 ` Viresh Kumar
2017-03-28 20:03 ` Leonard Crestez
2017-03-28 20:03 ` Leonard Crestez
2017-03-28 20:03 ` Leonard Crestez
2017-03-28 20:50 ` Rafael J. Wysocki
2017-03-28 20:50 ` Rafael J. Wysocki
2017-03-28 20:50 ` Rafael J. Wysocki
2017-03-28 22:23 ` Rafael J. Wysocki
2017-03-28 22:23 ` Rafael J. Wysocki
2017-03-22 16:53 ` [RFC 4/8] regulator: core: Check enabling bypass respects constraints Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
[not found] ` <1edff9bc610969b0c53fa1080d5db021c8e00b2d.1490199005.git.leonard.crestez-3arQi8VN3Tc@public.gmane.org>
2017-03-24 12:52 ` Mark Brown
2017-03-24 12:52 ` Mark Brown
2017-03-24 12:52 ` Mark Brown
2017-03-28 12:39 ` Leonard Crestez
2017-03-28 12:39 ` Leonard Crestez
2017-03-28 12:39 ` Leonard Crestez
[not found] ` <1490704781.3546.57.camel-3arQi8VN3Tc@public.gmane.org>
2017-03-28 16:47 ` Mark Brown
2017-03-28 16:47 ` Mark Brown
2017-03-28 16:47 ` Mark Brown
2017-03-28 19:49 ` Leonard Crestez
2017-03-28 19:49 ` Leonard Crestez
2017-03-28 19:49 ` Leonard Crestez
[not found] ` <1490730595.15830.1.camel-3arQi8VN3Tc@public.gmane.org>
2017-04-06 18:52 ` Mark Brown
2017-04-06 18:52 ` Mark Brown
2017-04-06 18:52 ` Mark Brown
[not found] ` <20170406185202.uixxcv3dgucrddgc-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2017-04-07 10:51 ` Leonard Crestez
2017-04-07 10:51 ` Leonard Crestez
2017-04-07 10:51 ` Leonard Crestez
2017-04-07 11:22 ` Mark Brown
2017-04-07 11:22 ` Mark Brown
[not found] ` <20170407112212.gzv3p7ldkh62657m-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2017-04-13 20:46 ` Leonard Crestez
2017-04-13 20:46 ` Leonard Crestez
2017-04-13 20:46 ` Leonard Crestez
2017-03-22 16:53 ` [RFC 5/8] regulator: anatop: fix min dropout for bypass mode Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-24 12:54 ` Mark Brown
2017-03-24 12:54 ` Mark Brown
2017-03-24 12:54 ` Mark Brown
2017-03-28 11:52 ` Leonard Crestez [this message]
2017-03-28 11:52 ` Leonard Crestez
2017-03-28 11:52 ` Leonard Crestez
2017-03-22 16:53 ` [RFC 6/8] regulator: core: Add regulator_is_bypass function Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
[not found] ` <e74c2f4d2b452cbe01aa2a48edde5c024212ffcb.1490199005.git.leonard.crestez-3arQi8VN3Tc@public.gmane.org>
2017-03-24 12:55 ` Mark Brown
2017-03-24 12:55 ` Mark Brown
2017-03-24 12:55 ` Mark Brown
2017-03-28 14:53 ` Leonard Crestez
2017-03-28 14:53 ` Leonard Crestez
2017-03-28 14:53 ` Leonard Crestez
2017-03-22 16:53 ` [RFC 7/8] cpufreq: imx6q: Initialize LDO bypass Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 17:09 ` Lucas Stach
2017-03-22 17:09 ` Lucas Stach
2017-03-22 17:09 ` Lucas Stach
[not found] ` <1490202585.29056.5.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2017-03-22 17:48 ` Leonard Crestez
2017-03-22 17:48 ` Leonard Crestez
2017-03-22 17:48 ` Leonard Crestez
2017-03-22 18:00 ` Lucas Stach
2017-03-22 18:00 ` Lucas Stach
2017-03-22 16:53 ` [RFC 8/8] ARM: dts: imx6qdl-sabresd: Enable fsl,ldo-bypass Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 16:53 ` Leonard Crestez
2017-03-22 17:13 ` Lucas Stach
2017-03-22 17:13 ` Lucas Stach
[not found] ` <1490202830.29056.8.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2017-03-29 13:32 ` Leonard Crestez
2017-03-29 13:32 ` Leonard Crestez
2017-03-29 13:32 ` Leonard Crestez
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