Re: [PATCH] mips: Realtek RTL: select NO_EXCEPT_FILL

[Olliver Schinagl]

On 19-02-2023 10:02, Thomas Bogendoerfer wrote:
> On Fri, Feb 17, 2023 at 08:27:05PM +0100, Olliver Schinagl wrote:
> > It is the Realtek series of SoC, specifically in my case, the RTL9302b,
> > which doesn't have a PCI peripherial, at all :) Nor configured in the
> > devicetree, but of course generic_mips_kernel enables the drivers, which
> > should be noop. I don't see anything related to PCI during boot.
> >
> > Having said that, the RTL930x series take their heritage from the RTL819x
> > (and probably older) wifi SoC series from realtek, which did contain a PCIe
> > peripherial, as that is where the (external) wifi chip was connected too.
> I see, and you want to use the already existing wifi driver ?
Not at all, the rtl930x is a pure switch chip (10 serdes connecting to 
multiple PHY's yielding 24 - 48 (+ some SFP port) configurations, all 
without anything PCI related.
> > > Do you have a programmers manual for it,
> > > which contains details about the PCI bridge ?
> > If only. There are some (leaked) datasheets, that do contain the PCI
> > registers, mostly (obviously) the rtl819x datasheets. https://github.com/libc0607/Realtek_switch_hacking/blob/files/REALTEK-RTL8196E.pdf
> > is one such example that contains the PCIe registers.
> that's just the PCIe PHY part, but not the localbus<->PCIe bridge
> part. But if the wifi part of ypur SOC is directly connected to
> the localbus, having the some PCI register won't help anyway.
> I am afraid you need to go the route via extra Kconfig section.

It's still odd though; as we do not have _anything_ PCI, but it 
SWAP_IO_SPACE causes the crash.

So in that case, we'll wend up with a duplicate of generic_mips_kernel - 
SWAP_IO_SPACE, any suggestions of doing this cleanly in kconfig? copy 
pasting the whole shebang (and maintaining it) seems wasteful.

I suppose the chip is generic, except one thing makes it not generic :(


What makes SWAP_IO_SPACE generic then? :)

> Thomas.