RE: [PATCH v4 1/2] arm64: dts: lx2160a: update PCIe nodes to match rev2 silicon

From: Leo Li
Date: Mon Sep 12 2022 - 16:25:52 EST




> -----Original Message-----
> From: Olof Johansson <olof@xxxxxxxxx>
> Sent: Monday, September 12, 2022 2:05 AM
> To: Leo Li <leoyang.li@xxxxxxx>
> Cc: shawnguo@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> robh+dt@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Z.Q. Hou <zhiqiang.hou@xxxxxxx>
> Subject: Re: [PATCH v4 1/2] arm64: dts: lx2160a: update PCIe nodes to match
> rev2 silicon
>
> Hi,
>
> On Wed, Aug 17, 2022 at 1:26 PM Li Yang <leoyang.li@xxxxxxx> wrote:
> >
> > The original dts was created based on the non-production rev1 silicon
> > which was only used for evaluation. Update the PCIe nodes to align
> > with the different controller used in production rev2 silicon.
>
> How can I confirm what version of silicon I have on a system?
>
> My non-evaluation commercially purchased system (HoneyComb LX2K) has:
>
> # cat /sys/bus/soc/devices/soc0/revision
> 1.0

This is different from the information I got. If there is still active Rev1.0 system in use, I would agree that we probably need to create a new device tree for the rev2 silicon. Thanks for the information.

>
> And I will be really grumpy if this system stops working. It's what I use to do
> all my maintainer work, even if that's been fairly dormant this year.
>
> It's overall setting off red flags to update an in-place devicetree to a "new
> revision" of silicon instead of adding a new DT for said revision. 2160A has
> been on the market for several years, so it just seems odd to all of the
> sudden retroactively make things non-backwards-compatible.
>
>
>
> -Olof
>
>
>
>
> -Olof