Re: [PATCH 1/5] Add the explanation and sample of RapidIO DTS sector to the document of booting-without-of.txt file.

[Segher Boessenkool <segher@kernel.crashing.org>]

> > > > > +    - device_type : Should be "rapidio"
> > > >
> > > > There is no OF binding, so no.
> > >
> > > So, we need to define it.
> >
> > If you want to.  Until that has been done, don't use
> > a "device_type".  Linux won't use it, anyway.
>
> Do you have another ideas about that? Only remove it?

Yeah, remove it.

> > > Using IP Block Revision is a
> > > clear choice.
> >
> > I don't think so.  For one thing, it describes a version of
> > a cell design, not a version of an actual device.  For another
> > thing, if I hear "8641" I know what you're talking about (sort
> > of, anyway), but I draw a blank stare if you say "v1.0".  I'm
> > sure I'm not the only one.  Concrete names are good.
>
> > From the different view ways, there are different results. Getting the
> version from RapidIO IP revision register is clear to me. :)

It's not in line with how all other "compatible" properties
are done though.

> > But the rapidio node doesn't know or care what the interrupts
> > are connected to, and neither should it.  That's what the
> > interrupt mapping recommended practice is for.
>
> There are no rapidio device in it. Doorbell, msg are all parts of
> rapidio controller.
> For example, 8641 rapidio controller have 2 msg unit: msg0 and msg1.
> They are not rapidio devices. Each msg unit has the tx_irq and rx_irq.

Ah, I think I understand what you mean now.  Yes, the binding
for this specific rapidio controller should define the _order_
of the interrupts in the "interrupts" property; but it cannot
define the format of the single entries, that is defined by
the interrupt controller node it is connected to already.

> > > > You want a #size-cells as well.
> > >
> > > The size is not used in this sector, so no defined.
> >
> > The size _is_ used; in the "ranges" property in this node,
> > for example.  It is also needed to describe the "reg" for
> > any child node of this node.
> >
> > A non-existant "#size-cells" means 1, and "#address-cells"
> > means 2, so in principle you could do without these
> > properties; but Linux doesn't parse the tree correctly in
> > that case (which reminds me, I have some more patches to
> > send).
>
> Ok, I'll add it in the next version for more religious.

It's not religious; true OF believers say leave the node
out if its value would be 1.  It's just that Linux doesn't
handle that properly yet, so you want to protect yourself :-)


Segher

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