Re: [PATCH 1/3] PCI: brcmstb: Break register definitions into separate header

[Florian Fainelli]

On 8/10/2021 8:10 AM, Jeremy Linton wrote:
> Hi,
>
> Thanks for taking a look at this!
>
>
> On 8/10/21 5:07 AM, Florian Fainelli wrote:
> > On 8/5/2021 2:11 PM, Jeremy Linton wrote:
> > > We are about to create a standalone ACPI quirk module for the
> > > bcmstb controller. Lets move the register definitions into a separate
> > > file so they can be shared between the APCI quirk and the normal
> > > host bridge driver.
> > >
> > > Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
> > > ---
> > >   drivers/pci/controller/pcie-brcmstb.c | 179 +------------------------
> > >   drivers/pci/controller/pcie-brcmstb.h | 182 ++++++++++++++++++++++++++
> > >   2 files changed, 183 insertions(+), 178 deletions(-)
> > >   create mode 100644 drivers/pci/controller/pcie-brcmstb.h
> >
> > You moved more than just register definitions into pcie-brcmstb.h you 
> > also moved internal structure definitions, enumerations, etc. which 
> > are not required since pcie-brcmstb-acpi.c does not access the 
> > brcm_pcie structure but open codes accesses to the MISC_STATUS 
> > register instead.
> >
> > There are no include guards added to this file (it is debatable 
> > whether we should add them), and it is also not covered by the 
> > existing BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE MAINTAINERS file 
> > entry.
>
> Sure, I will reduce the .h to just the register definitions, guard it, 
> and tweak maintainers to cover pcie-brcmstb*.
>
>
> > Given that there can be new platforms supported by this PCIe 
> > controller in the future possibly with the same limitations as the 
> > 2711, but with a seemingly different MISC_STATUS layout, you will have 
> > to think about a solution that scales, maybe we cross that bridge when 
> > we get there.
>
> Yes, given I don't know what those changes are I can't predict how they 
> would have to be handled, or even if the platform would be a target of 
> the community maintaining the UEFI/ACPI port on the RPi. So punting on 
> that topic seems a reasonable solution at the moment. Better yet, more 
> of the linux community will see the advantage of the firmware interface 
> and this platform can utilize that method.

Ideally newer platforms would support ECAM and would not require a 
custom quirk if nothing else, we do have discussions about that right 
now, although it is not clear to me how it will materialize into a 
product that people can buy.
--
Florian