Re: [Intel-gfx] [PATCH 16/16] drm/i915: Drop display.has_fpga_db from device info

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 10/05/2022 08:41, Jani Nikula wrote:
> On Tue, 10 May 2022, Joonas Lahtinen <joonas.lahtinen@linux.intel.com> wrote:
>> Quoting Souza, Jose (2022-05-09 17:19:28)
>>> On Mon, 2022-05-09 at 15:38 +0300, Joonas Lahtinen wrote:
>>>> Quoting José Roberto de Souza (2022-05-07 16:28:50)
>>>>> No need to have this parameter in intel_device_info struct
>>>>> as this feature is supported by Broadwell, Haswell all platforms with
>>>>> display version 9 or newer.
>>>>
>>>> This is opposite of the direction we want to move to.
>>>>
>>>> We want to embrace the has_xyz flags, instead of the macro trickery.
>>>
>>> This ever growing flag definition is causing problems when defining new platforms.
>>
>> The ever growing macros that change between kernel versions are much
>> more painful than easily printable list per SKU.
>>
>> Just to make it clear, a strict NACK from me for merging any patches
>> into this direction.
> 
> I was hoping to start a discussion to reach consensus on this with my
> mail [1], adding all maintainers in Cc, but merging started before the
> discussion really even started.
> 
> Obviously no further patches on this are to be merged, and the question
> now is really what to do with the ones that were. Revert?

 From the process standpoint strictly yes, but in practice I think there 
is no rush.

The ones which got merged I definitely do not like are:

Rc6 - because it creates an inconsistency where rc6p remains a device 
info flag.

DDI - because it is not 100% trivial and used from i915_irq.c. But a) I 
am not sure it is truly on an irq path, and b) it is display code so not 
my call anyway. (Affects the DP MST one as well by inheritance.)

The others are at best lukewarm to me - primarily because I am not 
convinced there is a benefit to it all. One day the need might come to 
move them back if some platforms drops support or something, which would 
be more churn. And it is handy to see a consolidated description of a 
platform in dmesg when looking at bugs. So just not sure it's an 
improvement.

Give there is much more conversions proposed I guess it may make sense 
to revert until overall consensus is achieved, since it may be odd to 
have a handful if we decide to stop there.

Regards,

Tvrtko