Re: [PATCH 0/2] J722S: DT Node cleanup for serdes0 and serdes1
From: Nishanth Menon
Date: Mon Apr 14 2025 - 10:55:45 EST
On 18:30-20250414, Siddharth Vadapalli wrote:
> On Mon, Apr 14, 2025 at 07:09:30AM -0500, Nishanth Menon wrote:
>
> Hello Nishanth,
>
> > On 10:57-20250412, Siddharth Vadapalli wrote:
> > > Hello,
> > >
> > > This series is based on the following series:
> > > https://patchwork.kernel.org/project/linux-arm-kernel/cover/20250408103606.3679505-1-s-vadapalli@xxxxxx/
> > > Based on the discussion in the above series which disabled 'serdes_wiz0'
> > > and 'serdes_wiz1' nodes in the SoC file and enabled them in the board
> > > file, Udit pointed out that it wasn't necessary to disable 'serdes0' and
> > > 'serdes1' in the SoC file anymore, since that is not a working
> > > configuration - serdes_wizX enabled and serdesX disabled doesn't work.
> > >
> > > Hence, this series aims to cleanup the serdesX nodes after the changes
> > > made by the above series.
> > >
> > > Regards,
> > > Siddharth.
> > >
> > > Siddharth Vadapalli (2):
> > > arm64: dts: ti: k3-j722s-main: don't disable serdes0 and serdes1
> > > arm64: dts: ti: k3-j722s-evm: drop redundant status within
> > > serdes0/serdes1
> > >
> > > arch/arm64/boot/dts/ti/k3-j722s-evm.dts | 2 --
> > > arch/arm64/boot/dts/ti/k3-j722s-main.dtsi | 4 ----
> > > 2 files changed, 6 deletions(-)
> > >
> > > --
> > > 2.34.1
> > >
> >
> >
> > I do not understand the logic here. serdes cannot operate without wiz
> > nodes, correct? why would we leave serdes on by default?
>
> Yes, serdesX requires serdes_wizX, but at the same time, serdesX is the
> child node of serdes_wizX. Therefore, without enabling serdes_wizX, we
> cannot enable serdesX.
>
> Prior to this series, but with the dependent series at:
> https://patchwork.kernel.org/project/linux-arm-kernel/cover/20250408103606.3679505-1-s-vadapalli@xxxxxx/
> applied, the nodes look like:
>
> serdes_wizX {
> ...
> status = "disabled";
>
> serdesX {
> ...
> status = "disabled";
> };
> };
>
> The dependent series fixes 'serdes_wizX' by disabling it in the SoC file
> k3-j722s-main.dtsi. But after the fix, we have a 'status = "disabled";'
> within the serdesX node which isn't required since:
> a) serdes_wizX enabled but serdesX disabled is non-functional and
> unusable
> b) serdes_wizX disabled in DT implies that serdesX is also disabled
Can we handle all of this in one series instead of two series?
--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D