Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API

From: Arnd Bergmann
Date: Mon Apr 18 2016 - 10:45:33 EST


On Monday 18 April 2016 15:03:51 Tomasz Nowicki wrote:
> On 16.04.2016 16:36, Jayachandran C wrote:
> > On Sat, Apr 16, 2016 at 1:01 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >> On Saturday 16 April 2016 12:50:13 Jayachandran C wrote:
> > The whole pci-thunder-*.c is to support thunder PCI quirks since the
> > generic OF is handled by pci-host-common.c and generic ECAM is now
> > separated - duplicating the whole file for ACPI will be bad.
>
> Yes, it would be too much code duplication. Also, we already know
> drivers which need quirks.
>
> We really need to agree on best approach here. Here are requirements
> which came up (please correct me if misunderstood sth):
>
> Arnd:
> 1. Initial DT driver should be standalone [Arnd]
> 2. No exported symbols [Arnd]
> 3. Duplicate necessary code to ACPI framework.

Correct.

> JC:
> 1. Adding linker section is wrong.
> 2. Quirks should be exported (pci_thunder_ecam_ops), then no need for
> adding linker section
> 3. To much duplication to copy code into the ACPI framework.
>
> My opinion:
> 1. I like linker section because it is easy to maintain and no need to
> export symbols.
> 2. We need more sophisticated algorithm for matching quirks (DMI is not
> enough and not only for ThunderX drivers). Of course I am open to any
> new suggestions.

Agreed.

> 3. To much duplication to copy code into the ACPI framework.
>
> Thanks in advance for any pointers.

Can you be more specific about what code actually would need to
be duplicated? Anything besides the config space operations?

Arnd