Is your platform coreboot-supported, if yes - have you tested it with coreboot?
On Thu, Feb 25, 2021 at 9:09 PM Rao G grao.v80@gmail.com wrote:
Hi Coreboot Team,
There is an external Monitor which works on HDMI/DVI and also DP , In BIOS the display is good whereas in OS (Ubuntu 18.04) until the kernel is initialized and i915 Video driver is loaded display is perfect, looks like the i915 OS driver switches off the monitor and there is no signal
Does ACPI GFX method have to return any External display specific data to the OS driver ? Tried to make changes to VBIOS but did not help, thought ASL code is missing under GFX0
From the OS following data can be read
External Monitor's EDID data can be read from I2C Bus Even VBT data from ACPI NVS can be read
Tried to dig into some of these files https://github.com/torvalds/linux/tree/master/drivers/gpu/drm/i915/display
intel_dp.c, intel_acpi.c to understand what function is turning off DP link when i have the OS debug driver logs, can send it across
Any clues will help, appreciate your time
PS:The platform has Intel BayTrail SoC, ValleyView chipset and VBIOS. The bios do not use GOP driver which replaces VBIOS
Thanks Rao _______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-leave@coreboot.org