Re: [RFCv1 1/3] phy: meson8b-usb2: Enable otg phy controller on Meson8b SoCs

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>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	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: [RFCv1 1/3] phy: meson8b-usb2: Enable otg phy controller on Meson8b SoCs
Date: Thu, 7 Feb 2019 12:11:15 +0530	[thread overview]
Message-ID: <CANAwSgRVypZ2CyendeOGJ9MZ6X951EwPW3x8K=0mru_Pj1qMLg@mail.gmail.com> (raw)
In-Reply-To: <CAFBinCAhjo4ueh6UDE+TKiF8Vc2Pz2JsjzcVsrsPQMU=ZEiLwQ@mail.gmail.com>

Hi Martin,

On Wed, 6 Feb 2019 at 17:18, Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> Hi Anand,
>
> On Tue, Feb 5, 2019 at 8:52 PM Anand Moon <linux.amoon@gmail.com> wrote:
> [...]
> > > personally I would start with getting device / peripheral mode working for usb0.
> > > if you're lucky the PHY driver will work without any changes and you
> > > only need to set the correct dr_mode along with the g-* properties.
> > >
> >
> > Yes that should be the goal on getting working usb0 phy and otg port.
> > So for now we will drop this patch and disable the usb_phy0 mode in
> > dts for Odroid c2
> > in order to get ride of the power failed WARNING.
> I checked Kevin's Odroid-C2 (GXBB) on Kernel CI and I can't see any
> power failed warning: [0]
>
> > When we get the usb0 node to work again with good phy configuration and
> > tuning we can re-enable the nodes. I will try to look into this in the future.
> >
> > Can you share your thought on this.
> sounds good to me! especially because it would give us OTG support on
> Meson8, Meson8b, Meson8m2 and GXBB (because these SoCs are sharing the
> same USB implementation)!
>
> I see four challenges:
> 1. getting host mode working on the micro USB port. you have already
> proven that you can do this :)
> 2. getting peripheral mode working on the micro USB port. my hope is
> that it's only about setting the right dr_mode and the g-* properties
> on the usb0 node (but I haven't tried this)
> 3. make OTG detection work and integrate it with dwc2. I would consult
> the dwc2 maintainers to see what can be done
> 4. bring everything together, making sure that one feature doesn't break another
>

Thanks for the feedback!
I will give this a try, In case I am stuck I will ask to you help.

>
> Regards
> Martin
>
>
> [0] https://storage.kernelci.org/next/master/next-20190130/arm64/defconfig/lab-baylibre-seattle/boot-meson-gxbb-odroidc2.html

Not a issue If I could reproduce my  kernel warning consistently again
I will share the boot log and the step I followed.
I will be dropping my patch for the initialization of usb0_phy untill
correct solution is-found.

Best Regards
-Anand

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