Re: genfb console on hybrid graphics

[David Hopper <dhop%nwlink.com@localhost>]

On Sat, 2020-01-04 at 23:26 +0000, David Brownlee wrote:
> On Thu, 2 Jan 2020 at 20:20, <dhop%nwlink.com@localhost> wrote:
> > [...]
> > In the hybrid boot case both genfb0 (Nvidia) and genfb1 (Intel) are
> > probed:
> > 
> > genfb0 at pci1 dev 0 funciton 0: NVIDIA product 1eb6 (rev. 0xa1)
> > [...]
> > genfb1 at pci0 dev 2 function 0: Intel UHD Graphics 630 (rev. 0x82)
> > 
> > ...but the console fails to attach-- I assume because it's trying
> > to use the
> > first possible framebuffer which is pointing the secondary
> > device.  What are
> > the settings I should be tweaking to test out performance of the
> > Intel
> > genfb-- if that's possible?
> 
> Pity about the BIOS modes - I remember that older Thinkpads had the
> full Integrated/Discrete/Optimax option :(
> How does the Nvidia probe in the discrete case? I wonder if you could
> run boot -c and disable it so its not picked up in hybrid mode

Thanks! I think that confirms a couple things for me

a) that genfb is known to have issues with hybrid / optimus mode, and I
think I did read that elsewhere, and--
b) a new rabbit hole, in that the boot -c userconf prompt (running
today's 9.99.33) spits out sporadic garbage and eventually locks up, so
I'll poke at that and see if I can narrow that issue down.

Thanks again!

> David

Dave