No external PCIe GPU possible/working on Gigabyte g41m-es2l

Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git, two nvidia gpu cards tested

I tried to use some external GPU on a g41m-es2l to get some digial screen output. It does not seem to work. When having build coreboot with native vga-init for the internal intel gpu, i never get a output from the nvidia card. When i connect the analog VGA cable to the internal intel gpu and boot up i can see many nouveau (memory-space?) errors. Both GPUs (nvidia and intel) are then enabled at once. Kernel 4.10 cant boot.

I tried removing the native vga-init. The only change is then that the Intel GPU works only when the kernel have load. Nvidia card deliver still same errors.

With OEM-bios the intel card gets disabled and a PCIe GPU works fine.

[Arthur Heymans]

 writes:
> Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git, two nvidia gpu cards tested
>
> I tried to use some external GPU on a g41m-es2l to get some digial screen output. It does not seem to work. When having build coreboot with native vga-init for
> the internal intel gpu, i never get a output from the nvidia card. When i connect the analog VGA cable to the internal intel gpu and boot up i can see many
> nouveau (memory-space?) errors. Both GPUs (nvidia and intel) are then
> enabled at once. Kernel 4.10 cant boot.

Indeed the internal GPU should be disabled if an external GPU is
detected. Afaik there is only one northbridge that currently does this
for desktop boards which can have a wide variety of things in that slot
and this is i945. (It disables integrated GPU in romstage)  Maybe this
code can be reused?
> I tried removing the native vga-init. The only change is then that the
> Intel GPU works only when the kernel have load. Nvidia card deliver
> still same errors.

Whether the hardware is initialised or not makes no difference to the
fact that is enabled/disabled. Linux is sometimes unhappy if no form of
initialisation (option rom or native) has been performed.
> With OEM-bios the intel card gets disabled and a PCIe GPU works fine.

OEM bios does the right thing :)

[Arthur Heymans]

Arthur Heymans  writes:
>  writes:
> > Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git, two nvidia gpu cards tested
> >
> > I tried to use some external GPU on a g41m-es2l to get some digial
> > screen output. It does not seem to work. When having build coreboot
> > with native vga-init for
> > the internal intel gpu, i never get a output from the nvidia
> > card. When i connect the analog VGA cable to the internal intel gpu
> > and boot up i can see many
> > nouveau (memory-space?) errors. Both GPUs (nvidia and intel) are then
> > enabled at once. Kernel 4.10 cant boot.
>
> Indeed the internal GPU should be disabled if an external GPU is
> detected. Afaik there is only one northbridge that currently does this
> for desktop boards which can have a wide variety of things in that slot
> and this is i945. (It disables integrated GPU in romstage)  Maybe this
> code can be reused?

Seems I was wrong. Adding a correct disable operation to the internal
graphic device should do it. The allocator will detect 2 graphic devices
and if internal one has a disable op, it will be disabled.

This might fix it:
https://review.coreboot.org/#/c/18504/

[Stefan Reinauer]

* [e-mail]  [170226 21:59]:
> Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git, two
> nvidia gpu cards tested
>
> I tried to use some external GPU on a g41m-es2l to get some digial screen
> output. It does not seem to work. When having build coreboot with native
> vga-init for the internal intel gpu, i never get a output from the nvidia card.
> When i connect the analog VGA cable to the internal intel gpu and boot up i can
> see many nouveau (memory-space?) errors. Both GPUs (nvidia and intel) are then
> enabled at once. Kernel 4.10 cant boot.
>
> I tried removing the native vga-init. The only change is then that the Intel
> GPU works only when the kernel have load. Nvidia card deliver still same
> errors.
>
> With OEM-bios the intel card gets disabled and a PCIe GPU works fine.

Please provide coreboot boot logs.

Stefan

[Arthur Heymans]

Stefan Reinauer  writes:
> [e-mail]  [170226 21:59]:
> > Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git, two
> > nvidia gpu cards tested
> >
> > I tried to use some external GPU on a g41m-es2l to get some digial screen
> > output. It does not seem to work. When having build coreboot with native
> > vga-init for the internal intel gpu, i never get a output from the nvidia card.
> > When i connect the analog VGA cable to the internal intel gpu and boot up i can
> > see many nouveau (memory-space?) errors. Both GPUs (nvidia and intel) are then
> > enabled at once. Kernel 4.10 cant boot.
> >
> > I tried removing the native vga-init. The only change is then that the Intel
> > GPU works only when the kernel have load. Nvidia card deliver still same
> > errors.
> >
> > With OEM-bios the intel card gets disabled and a PCIe GPU works fine.
>
> Please provide coreboot boot logs.
>
> Stefan

Actually https://review.coreboot.org/#/c/18504/
https://review.coreboot.org/#/c/18511/ (not sure if needed) and 
https://review.coreboot.org/#/c/18513/ (works but might be improved)
fix this issue.

[qma ster]

Maybe to fix this PCIe GPU issue he just needs to edit a
*./coreboot/src/device/Kconfig
*file?

*./coreboot/src/device/Kconfig*
change

config MULTIPLE_VGA_ADAPTERS
   bool
   default n

to

config MULTIPLE_VGA_ADAPTERS
   bool
   default y

and completely rebuild the coreboot

I enabled these options for my G505S laptop with both integrated/discrete
graphic, however I am not a gamer so can't notice if there is any positive
effect from this option. But maybe this option will significantly improve
the thread starter's eGPU experience? What do you think ?

2017-02-28 0:57 GMT+03:00 Arthur Heymans :
> Stefan Reinauer  writes:
> > [e-mail]  [170226
>
> 21:59]:
> > > Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git,
>
> two
> > > nvidia gpu cards tested
> > >
> > > I tried to use some external GPU on a g41m-es2l to get some digial
>
> screen
> > > output. It does not seem to work. When having build coreboot with native
> > > vga-init for the internal intel gpu, i never get a output from the
>
> nvidia card.
> > > When i connect the analog VGA cable to the internal intel gpu and boot
>
> up i can
> > > see many nouveau (memory-space?) errors. Both GPUs (nvidia and intel)
>
> are then
> > > enabled at once. Kernel 4.10 cant boot.
> > >
> > > I tried removing the native vga-init. The only change is then that the
>
> Intel
> > > GPU works only when the kernel have load. Nvidia card deliver still same
> > > errors.
> > >
> > > With OEM-bios the intel card gets disabled and a PCIe GPU works fine.
> >
> > Please provide coreboot boot logs.
> >
> > Stefan
>
> Actually https://review.coreboot.org/#/c/18504/
> https://review.coreboot.org/#/c/18511/ (not sure if needed) and
> https://review.coreboot.org/#/c/18513/ (works but might be improved)
> fix this issue.