[PATCH 00/11] GuC changes for flicker-free boot.

[Maarten Lankhorst]

Hey,

On 2025-01-21 13:10, Jani Nikula wrote:
> On Tue, 10 Dec 2024, Maarten Lankhorst <dev at lankhorst.se> wrote:
>> Ignore the first 5 patches in this series, it's sent as a separate series.
>> https://patchwork.freedesktop.org/series/142241/
> 
> For them I've replied in [1] that they need more explanations in the
> commit messages.
> 
Thanks, I'll try to clarify and reword those commits, then send a new 
version.

Xe init sequence has to support memirq's, but obviously memirq's require 
memory allocations. Right now this happens before FB handover. Similarly 
GuC also performs some initialisations that happen before FB handover. 
Lastly we are also doing loading the other UC too early.

Any of these will cause the initial FB to be garbled. The solution is to 
change the µC load ordering to be the minimal required to support VF,
delay any GT and µC initialisation until after FB handover, and only 
then enable memirqs and all interrupts.

This obviously means that FB handover has to run on Xe without 
interrupts enabled. It cannot be enabled because of memirq's.

I chose to deviate here from i915, because it supports platforms that 
don't have a strict distinction between display and graphics.

Cheers,
~Maarten