RE: [EXT] Re: [PATCH v2 1/4] dt-bindings: perf: fsl-imx-ddr: Add i.MX95 compatible

From: Xu Yang
Date: Sun Dec 10 2023 - 00:00:27 EST


Hi Conor,

> On Fri, Dec 08, 2023 at 04:53:59PM +0800, Xu Yang wrote:
> > i.MX95 has a DDR pmu. This will add a compatible for it.
>
> On v1 we had a discussion because the commit message wasn't clear about
> whether or not the device was compatible with existing ones. For some
> reason, the v2 patch _removes_ information from the commit message
> rather than tries to explain.
> This [1] message of yours, that I didn't get a chance to reply to before
> you sent this new version, seems to say that there should be an
> imx93-ddr-pmu fallback.

Thanks for your comments.

Just read my previous comment in [1] and found I made a mistake.
Now I'll try to clarify it here.

Imx95 and imx93 have different AXI filter configuration. I need a
compatible for imx95 since the driver cannot differentiate them.

Then I need to consider below two options:
1. compatible = "fsl,imx95-ddr-pmu", "fsl,imx93-ddr-pmu"
2. compatible = "fsl,imx95-ddr-pmu"

Both of them work correctly on imx95. When I make changes in
driver for imx95, imx93 is not affected.

For basic functions, imx95 is compatible with imx93. I select the 2rd
form for simplicity. If the first form is optimal, I can change it in next
version.

Thanks,
Xu Yang

>
> Cheers,
> Conor.
>
> 1 -
> https://lore.kernel.org/all/DB7PR04MB514668A8B172CD1A2187BC408C84A@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
>
> >
> > Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
> >
> > ---
> > Changes in v2:
> > - no changes
> > ---
> > Documentation/devicetree/bindings/perf/fsl-imx-ddr.yaml | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/Documentation/devicetree/bindings/perf/fsl-imx-ddr.yaml b/Documentation/devicetree/bindings/perf/fsl-imx-
> ddr.yaml
> > index e9fad4b3de68..1bc7bf1c8368 100644
> > --- a/Documentation/devicetree/bindings/perf/fsl-imx-ddr.yaml
> > +++ b/Documentation/devicetree/bindings/perf/fsl-imx-ddr.yaml
> > @@ -20,6 +20,7 @@ properties:
> > - fsl,imx8mn-ddr-pmu
> > - fsl,imx8mp-ddr-pmu
> > - fsl,imx93-ddr-pmu
> > + - fsl,imx95-ddr-pmu
> > - items:
> > - enum:
> > - fsl,imx8mm-ddr-pmu
> > --
> > 2.34.1
> >