[M] Change in coreboot[master]: soc/intel/common/block: Add Intel VGA early graphics support

[Subrata Banik (Code Review)]

Attention is currently required from: Bora Guvendik, Zhixing Ma, Anil Kumar K, Hannah Williams, Cliff Huang, Tarun Tuli, Nico Huber, Michał Żygowski, Jérémy Compostella, Paul Menzel, Arthur Heymans, Swift Geek (Sebastian Grzywna).

Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/70299 )

Change subject: soc/intel/common/block: Add Intel VGA early graphics support
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Patch Set 30:

(1 comment)

File src/soc/intel/common/block/graphics/early_graphics.c:

https://review.coreboot.org/c/coreboot/+/70299/comment/7fb5e346_1290eafe 
PS28, Line 6: static bool initialized;
> Once the TXT code has merged the only function that is really SoC specific is `early_graphics_soc_panel_init()`. Everything else it about IGD BAR 0 and could be moved here.
>
> However, I don't think that checking on BAR 0 make sense because 
> FSP-M configures BAR 0 regardless of if we called `early_graphics_init()`.

the reason that you are checking this `initialized` variable is to know if you can continue with gma_gfxstop() function call isn't it? Also, you would like to make sure gma_gfxstop() call remain in parity with previous gma_gfxinit() call.

Finally, what is the risk of calling into gma_gfxstop() (w/ valid IGD bar) assuming  for some reason early_graphics_init() has failed ? If you don't see any risk then just checking the BAR remain valid and claimed is enough.