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

[Florian Fainelli <f.fainelli@gmail.com>]

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@arm.com>
>>> ---
>>>   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