Re: [RFC PATCH 0/4] Add ACPI support for HiSilicon PCIe Host Controllers

[Arnd Bergmann <arnd@arndb.de>]

On Thursday 04 February 2016 15:11:18 Gabriele Paoloni wrote:
> > 
> > ACPI has its own PCI support, and should not need drivers for host
> > bridges. I don't think we can really mix the two things, as ACPI
> > needs to have access to things like PCI config space way before
> > we are probing normal device drivers.
> > 
> > Please put this in drivers/acpi/pci*.c.
> 
> I can put pcie-hisi-acpi.c under drivers/acpi/
> 
> However if you look at the driver it is made up of three parts:
> pcie-hisi.c --> the DT based driver
> pcie-hisi-acpi.c --> the ACPI based hook and ACPI specific init callback
> pcie-hisi-common.c --> common functions shared between DT and ACPI versions 
>                        of the driver
> 
> Now I think that moving pcie-hisi-acpi.c under drivers/acpi/
> would make it hard to read as you need to jump across directories
> and it seems a bit unnatural...
> 
> However it is not a big issue to me...

That's not really what I meant though: the pcie-hisi driver uses the
pcie-designware.c library, most of which makes no sense in an environment
where you have ACPI, e.g. link training, custom MSI support, initial
register setup, platform driver hooks, etc.

You should add a very minimal set of hacks for the parts in this driver
that diverge from a standard SBSA compliant PCIe host that ACPI expects.

	Arnd