Re: [PATCH v5 5/6] arm64: dts: cix: add initial CIX P1(SKY1) dts support

[Peter Chen <peter.chen@cixtech.com>]

> >
> > On 25-03-25 10:52:10, Marc Zyngier wrote:
> > > > +     timer {
> > > > +             compatible = "arm,armv8-timer";
> > > > +             interrupt-names = "sec-phys", "phys", "virt", "hyp-phys", "hyp-virt";
> > > > +             interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW 0>,
> > > > +                          <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW 0>,
> > > > +                          <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW 0>,
> > > > +                          <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW 0>,
> > > > +                          <GIC_PPI 12 IRQ_TYPE_LEVEL_LOW 0>;
> > > > +     };
> > > > +};
> > >
> > > I don't think there is anything wrong here, but it is also a pretty
> > > useless DT. There isn't even a UART to interact with the machine and
> > > find out whether it has actually booted.
> > >
> >
> > UEFI uses the same UART, so we could see all kernel boot logs until
> > switch to use kernel UART driver for printk. If you would like boot
> > to the console at initramfs, just add uart node like patchset v1.
> 
> What's the point in upstreaming something that requires extra changes
> just to boot it? It only outlines these patches are not useful as they
> stand.
> 
> >
> > > I reckon this should be part of the initial DT, as this otherwise
> > > serves little purpose.
> > >
> >
> > Without this initial support, we can't add some base drivers, like
> > mailbox. The dt_binding_check will report warnings/errors [1].
> 
> Of course you can. You just add additional patches to this series,
> making it something that is actually useful. So far, this series only
> serves as marketing material.
> 
> > Full UART support depends on clock, clock control needs mailbox
> > to talk with FW using SCMI protocol.
> 
> Then do it. You obviously have existing DT support for it already.
> 
> > There is no any support for CIX SoC, so we had to add one small step by
> > step.
> 
> No, you are deliberately choosing to make this platform useless.
> 
> That's a bit sad, and a waste of everybody's time.
> 

Hi Marc,

Thanks for your interesting of our platform, and your comments
help us a lot. But I don't think it wastes reviewers and maintainers
time, a clean patch set saves everyone's time during upstream process.

For how to organize the patch set for SoC, Krzysztof gave good summary
at [1]. We are going on upstream [2], this patch set is just a start
and base but not like you said for marketing purpose.

[1] https://lore.kernel.org/linux-samsung-soc/CADrjBPq_0nUYRABKpskRF_dhHu+4K=duPVZX==0pr+cjSL_caQ@mail.gmail.com/T/#m2d9130a1342ab201ab49670fa6c858ee3724c83c
[2] https://lore.kernel.org/lkml/20250325101807.2202758-1-guomin.chen@cixtech.com/

-- 

Best regards,
Peter