Re: [PATCHv3 1/2] ARM64: dts: meson-gxbb-odroidc2: Fix usb phy reset warning

From: Anand Moon <linux.amoon@gmail.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: devicetree <devicetree@vger.kernel.org>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Kevin Hilman <khilman@baylibre.com>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Rob Herring <robh+dt@kernel.org>,
	linux-amlogic@lists.infradead.org,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Jerome Brunet <jbrunet@baylibre.com>
Subject: Re: [PATCHv3 1/2] ARM64: dts: meson-gxbb-odroidc2: Fix usb phy reset warning
Date: Wed, 6 Feb 2019 01:23:45 +0530	[thread overview]
Message-ID: <CANAwSgT_q6zDVC8UVz+hrzA5Hn34eT_k-ZGB2LTO3dauT45T7g@mail.gmail.com> (raw)
In-Reply-To: <CAFBinCBjF5iOkUjhxSGXpQa7Nc1=bWAzA=XjrfXRYxSPZO15nQ@mail.gmail.com>

hi Martin,

On Tue, 5 Feb 2019 at 02:19, Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> Hi Anand,
>
> On Mon, Feb 4, 2019 at 9:04 PM Anand Moon <linux.amoon@gmail.com> wrote:
> [...]
> > > > @@ -36,6 +43,8 @@
> > > >                 regulator-min-microvolt = <5000000>;
> > > >                 regulator-max-microvolt = <5000000>;
> > > >
> > > > +               vin-supply = <&p5v0>;
> > > did you find out why this patch fixes the USB_OTG_PWR regulator?
> > > based on just reading the patch I can't find an explanation myself
> > >
> >
> > As per the device tree binding we need this setting to enable power input source
> > [0] Documentation/devicetree/bindings/regulator/fixed-regulator.txt
> >
> > *I have observed few more place where this setting is missing*
> OK, I understand that we should describe the hierarchy of the regulators
>
> > > have you tested without this patch to rule out that you hit some bug
> > > in the regulator framework back when you wrote the patch?
> > > (I don't have an Odroid-C2 so I can't test this myself).
> > >
> >
> > Yes I have tested this patch.Some device like usb camera and usb hard drive
> > when connected to usb port will generate warning message.
> > which shows us that not enough power is being set to the port.
> I don't understand why adding "p5v0" as parent of "usb_otg_pwr"
> changes the output of "usb_otg_pwr":
> - "p5v0" is a fixed regulator which cannot be controlled at all (apart
> from removing power from it)
> - "usb_otg_pwr" does not have any current limits set inside the .dts
> - "usb_otg_pwr" has the same fixed voltage as the new "p5v0" regulator
>
> what are your steps-to-reproduce for your original issue ("reset
> high-speed USB device number 3 using dwc2")?
>

I have tried to reproduce this but some how I cannot get the logs
I might have enable some more debug options to reproduce but currently
it's lost.
because of over flashing of the operating system on sdcards.

But definitely this fix the power issue needed to get usb-storage
device to work on Odroid c1/c2 boards.

>
> Regards
> Martin

Best Regards

-Anand

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