Re: [PATCH] drm/i915/gmbus: Add Wa_16025573575 for PTL for bit-bashing

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 13 Jun 2025, "Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com> wrote:
> On 6/12/2025 5:30 PM, Gustavo Sousa wrote:
>> Instead of open-coding the conditions for the workaround in three
>> different places in the file, I think we should have a function
>> needs_wa_16025573575() and use it.
>>
>> Also, note that the workaround is also required for WCL (display version
>> 30.02), and we would then include that in needs_wa_16025573575().
>
> I agree, will make a separate function needs_wa_16025573575().
>
> Thanks for the suggestions. I will make suggested changes in next revision.

Please let's aim for something a little more generic and unified than
that, and one that can be easily extended and switched to a generated
version in the future.

intel_display_wa.h:

enum intel_display_wa {
	INTEL_DISPLAY_WA_16025573575,
};

bool __intel_display_wa(struct intel_display *display, enum intel_display_wa wa);

#define intel_display_wa(__display, __wa) __intel_display_wa((__display), INTEL_DISPLAY_WA_ ## __wa)

In code you'd use:

	if (intel_display_wa(display, 16025573575))

For now, you'd manually check for each enum in __intel_display_wa()
implementation, but in the future that code could be generated similar
to what xe currently has. I'm just not very enthusiastic about adding C
language hostprogs with custom .rules files and parsing.


BR,
Jani.


-- 
Jani Nikula, Intel