Re: [PATCH v3 1/6] dt-bindings: PCI: Add binding for qps615

Manivannan Sadhasivam
2024-11-28T13:24:41Z

On Tue, Nov 26, 2024 at 07:58:16AM +0100, Krzysztof Kozlowski wrote:
> On 26/11/2024 07:50, Krishna Chaitanya Chundru wrote:
> >
> >
> > On 11/25/2024 1:10 PM, Krzysztof Kozlowski wrote:
> >> On 24/11/2024 02:41, Krishna Chaitanya Chundru wrote:
> >>>> ...
> >>>>
> >>>>> + qps615,axi-clk-freq-hz:
> >>>>
> >>>> That's a downstream code you send us.
> >>>>
> >>>> Anyway, why assigned clock rates do not work for you? You are
> >>>> re-implementing legacy property now under different name :/
> >>>>
> >>>> The assigned clock rates comes in to the picture when we are
> >>>> using clock
> >>> framework to control the clocks. For this switch there are no
> >>> clocks needs to be control, the moment we power on the switch
> >>> clocks are enabled by default. This switch provides a mechanism to
> >>> control the frequency using i2c. And switch supports only two
> >>> frequencies i.e
> >>
> >>
> >> frequency of what, since there are no clocks?
> >>
> > The axi clock frequency internal to the switch, host can't control
> > the enablement of the clocks it can control only the frequency.
> >
> > we already had a discussion on this on v2[1], and we taught you agreed
> > on this property.
> >
> > [1]
> > https://lore.kernel.org/netdev/d1af1eac-f9bd-7a8e-586b-5c2a76445145@codeaurora.org/T/#m3d5864c758f2e05fa15ba522aad6a37e3417bd9f
> >
>
> This points something else. I diged v2 and found many unanswered
> questions and unfinished discussion:
>

The conversation is here:
https://lore.kernel.org/linux-arm-msm/20240823094028.7xul4eoiexey5xjm@thinkpad/

But there was no explicit agreement on the usage of 'qps615,axi-clk-freq-hz'.

If describing the PCI device's internal clock frequency is not applicable, then
I'd recommend to change the clock rate in the driver itself based on the number
of DSPs enabled (or based on other configuration).

- Mani

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