Re: [PATCH 2/3] ARM: DTS: imx6q-logicpd: Reduce inrush current on start
On Wed, Mar 20, 2019 at 08:41:27AM -0500, Adam Ford wrote:
> On Wed, Mar 20, 2019 at 7:45 AM Shawn Guo wrote:
> >
> > On Wed, Mar 06, 2019 at 08:04:00AM -0600, Adam Ford wrote:
> > > The main 3.3V regulator sources a series of additional regulators.
> > > This patch adds a small delay, so when the 3.3V regulator comes
> > > on it delays a bit before the subsequent regulators can come on.
> > > This reduces the inrush current a bit on the external DC power
> > > supply.
> > >
> > > Fixes: 1c207f911fe9 ("ARM: dts: imx: Add support for Logic PD
> > > i.MX6QD EVM")
> >
> > Same comment as patch #1.
>
> The sourcing regulator occasionally cuts out because the inrush is so
> high. I would argue that preventing a hardware issue like that would
> be a 'fix' and if it helps, I could add that to the description.
Yes, if you would like to get it in as a fix, please elaborate the real
world issue it fixes.
Shawn
Re: [PATCH 2/3] ARM: DTS: imx6q-logicpd: Reduce inrush current on start
On Wed, Mar 20, 2019 at 7:45 AM Shawn Guo wrote:
>
> On Wed, Mar 06, 2019 at 08:04:00AM -0600, Adam Ford wrote:
> > The main 3.3V regulator sources a series of additional regulators.
> > This patch adds a small delay, so when the 3.3V regulator comes
> > on it delays a bit before the subsequent regulators can come on.
> > This reduces the inrush current a bit on the external DC power
> > supply.
> >
> > Fixes: 1c207f911fe9 ("ARM: dts: imx: Add support for Logic PD
> > i.MX6QD EVM")
>
> Same comment as patch #1.
The sourcing regulator occasionally cuts out because the inrush is so
high. I would argue that preventing a hardware issue like that would
be a 'fix' and if it helps, I could add that to the description.
>
> >
> > Signed-off-by: Adam Ford
>
> To match the convention, the 'DTS' in subject prefix should be
> lowercase.
I will fix in V2.
>
> Shawn
adam
>
> >
> > diff --git a/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> > b/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> > index fb01fa6e4224..e31b6923cb72 100644
> > --- a/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> > +++ b/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> > @@ -99,6 +99,7 @@
> > regulator-min-microvolt = <330>;
> > regulator-max-microvolt = <330>;
> > gpio = < 26 GPIO_ACTIVE_HIGH>;
> > + startup-delay-us = <7>;
> > enable-active-high;
> > regulator-always-on;
> > };
> > --
> > 2.17.1
> >
Re: [PATCH 2/3] ARM: DTS: imx6q-logicpd: Reduce inrush current on start
On Wed, Mar 06, 2019 at 08:04:00AM -0600, Adam Ford wrote:
> The main 3.3V regulator sources a series of additional regulators.
> This patch adds a small delay, so when the 3.3V regulator comes
> on it delays a bit before the subsequent regulators can come on.
> This reduces the inrush current a bit on the external DC power
> supply.
>
> Fixes: 1c207f911fe9 ("ARM: dts: imx: Add support for Logic PD
> i.MX6QD EVM")
Same comment as patch #1.
>
> Signed-off-by: Adam Ford
To match the convention, the 'DTS' in subject prefix should be
lowercase.
Shawn
>
> diff --git a/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> b/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> index fb01fa6e4224..e31b6923cb72 100644
> --- a/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> +++ b/arch/arm/boot/dts/imx6-logicpd-baseboard.dtsi
> @@ -99,6 +99,7 @@
> regulator-min-microvolt = <330>;
> regulator-max-microvolt = <330>;
> gpio = < 26 GPIO_ACTIVE_HIGH>;
> + startup-delay-us = <7>;
> enable-active-high;
> regulator-always-on;
> };
> --
> 2.17.1
>
