Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/33738 )
Change subject: device/Kconfig: Add HAVE_EXT_GFX kconfig ......................................................................
Patch Set 4:
Patch Set 4:
Patch Set 3:
Patch Set 3: Code-Review-1
Patch Set 3:
Patch Set 3: Code-Review-1
conflicts with Kconfig choice "Graphics initialization"
'Graphics initialization" choice been designed with a viewpoint that it can only work with onboard GFX and doesn't consider any future option of only enable graphics over external card.
That's not true. It works with dGPUs already. Just select VGA_ROM_RUN.
yes VGA_ROM_RUN should work for dGPU but today default VGA_ROM_RUN if VGA_BIOS where you like to include vga rom inside your cbfs with vid:did etc. I'm not telling it won't work dGPU over PCIe but its not well managed.
Yes, that's true. External GPUs and multi GPU handling has never been a priority when adding new platforms. In case the mainboard doesn't have libgfxinit / native graphics init support, the default selection would already be VGA_ROM_RUN.
I don't understand what you mean by conflicts with Graphics initialization? Using this Kconfig, i wish to select a bunch of required kconfig at once rather selecting from SOC/mainboard.
It conflicts with the existing choice as it selects specific Kconfigs for no reason.
Eventually selecting VGA_ROM_RUN might selects few kconfig inherently which i have forced select using ENABLE_EXT_GFX so, it won't prompt. I understand your argument, but please check it will not duplicate the entire list of selection.
Looking at the next commit it only works for specific mainboard, which have the IGD disabled. If the mainboard doesn't have IGD, only PEG ports, why do you need a Kconfig for that? FSP should initialize the PEG port in all cases if it's marked as 'on'. The skylake code is able to handle external GPUs already.
[Subrata] I'm not trying to enable display over PEG ports, rather i'm planning to use PCIE over PCH to bring display. if you see there are 4 option 1. IGD 2. PEG 3. PCIE 4. Hybrid
I'm working to enable PCIE GFX cards to enable over PCH root bridge.
Maybe you should give more details about the problem you encounter on your platform.
How do my mainboard convey to my soc code that don't initialize onboard GFX and only lunch oprom in real mode with certain vesa mode set ? isn't it better we club everything under still Kconfig? i can achieve my work without this CL then i had to select multiple Kconfigs at make ?