Attention is currently required from: Arthur Heymans, Julius Werner, Kapil Porwal, Lean Sheng Tan, Nick Vaccaro, Werner Zeh.
Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/78080?usp=email )
Change subject: soc/intel/cmn/gfx: Add API to report presence of external display ......................................................................
Patch Set 1:
(1 comment)
File src/soc/intel/common/block/graphics/graphics.c:
https://review.coreboot.org/c/coreboot/+/78080/comment/79083a94_3916e6e2 : PS1, Line 59: #if CONFIG(REPORT_EXTERNAL_DISPLAY_AT_PREBOOT)
Are there really platforms using this file for which this code doesn't work? Otherwise you should probably `select` this option from CONFIG_SOC_INTEL_COMMON_BLOCK_GRAPHICS and then assume it is set here.
this code will work for all the users of graphics.c but due to limitation in display init in all prior generations of MTL, I have limited the selection.
due to the below reason, i have only let MTL select this config
Only MTL does the external device init when LID is closed and eDP still attached. All platforms prior to that ended up init the eDP although the LID is closed. Hence, those devices are not looking at the external display aka already assumes eDP is present. In such a case, what is the point of reading the register and detecting if EDP is present. I can tell devices prior to MTL always assume eDP is present at pre-boot.