On Wed, Aug 11, 2021 at 5:05 AM Rao G <grao....@gmail.com> wrote: > > Thanks Nico for your response. > > > am expecting some register should set with eDP as interface and when > > display is connected > > > > any clue why the i915 OS driver was turning off DP display in case 2? > I assume the HPD signal doesn't get through to the software. > > [Rao] > You mean I need to check PORT_HOTPLUG_EN and PORT_HOTPLUG_STAT mmio offsets > for this issue? > BIOS display is fine, Windows logo is also seen but there is no signal when > "windows login" is reached
IME, that's almost always due to incorrect/missing/mismatched VBT data in the ACPI opregion/mailbox > > It had similar behaviour w.r.t to ubuntu 18.04, I configured DDI1 to "DP with > HDMI/DVI" > > Can this issue be fixed with VBE data configured through BMP or it needs a > fix from graphics MMIO? > > Regards > Rao > > On Fri, Jul 30, 2021 at 10:27 PM Nico Huber <nic...@gmx.de> wrote: >> >> On 30.07.21 18:59, Rao G wrote: >> > Thanks Nico. >> > >> > HPD is active , measured the signal >> >> Is your coreboot port public somewhere? If the hardware is fine, maybe >> the firmware isn't? >> >> > >> > Configured Ports >> > 1.DDI0- PortB - DP with HDMI/DVI is good in BIOS & OS >> > 2.DDI1- PortC - DP with HDMI/DVI is good in BIOS, i915 was turning off the >> > DP display (Never understood the reason) >> >> It's very suspicious that these two behave differently. Does the HPD >> signal (MMIO read) work for DDI0? >> >> > >> > So configured PortC with eDP >> > >> > If there is no way BIOS to detect the external display with MMIO registers >> > when configured as eDP, Can i not turn off the DDI1/Port C at runtime in >> > BIOS, >> >> Maybe it's time to switch to an open-source solution? libgfxinit will >> probably have the same issue, but it might be possible to get a rather >> short delay. >> >> > am expecting some register should set with eDP as interface and when >> > display is connected >> > >> > any clue why the i915 OS driver was turning off DP display in case 2? >> >> I assume the HPD signal doesn't get through to the software. >> >> Nico > > _______________________________________________ > coreboot mailing list -- coreboot@coreboot.org > To unsubscribe send an email to coreboot-le...@coreboot.org _______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-le...@coreboot.org
