hybrid-graphics-linux team mailing list archive

[Lekensteyn <lekensteyn@xxxxxxxxx>]

Hi Michael,

On Tuesday 04 September 2012 23:37:46 Michael Rodríguez-Torrent wrote:
> Looking at nvidia-settings, I can see that both graphics chips are
> recognized. GPU 0 (integrated) has "X screens: Screen 0" and "Display
> Devices: Seiko/Epson (DFP-0)" (which is the laptop screen, while GPU 1 has
> "X screens: None" and "Display Devices: CRT-0 (CRT-0)" (?)
Looks logical to me. That CRT-0 is possibly not connected to anthing (I have 
the same unconnected CRT-0 here as many others do). Your laptop is not an 
Optimus laptop if you were wondering that.

> So, the discrete card is always running and somehow gets configured with a
> (bogus?) display, while the integrated card gets the laptop LCD.
Well, if there was an Intel iGPU taking it, there would be no use for the 
second nvidia card right?

> I found that a lot of people have posted about trying to set the BusID in
> xorg.conf to that of the discrete card. I tried this as well but, like
> them, found this resulted in the laptop screen going blank once X starts.

> Is there a reason that the card wouldn't be driving the display?
If the discrete GPU is not connected to a screen, surely you get a blank 
screen.

> Is there something more I can do to tie them together?
Maybe https://wiki.archlinux.org/index.php/Dell_Studio_XPS_13

> I've also had a look at the ACPI tables (e.g.
> https://launchpadlibrarian.net/24358773/DSDT.dsl), and I can see that the
> calls to switch the discrete card on and off are obvious because of their
> debug logging ("MXM on/off"). There are two other methods in the same
> scope, "HSTA" and "_ROM," but I can't tell what they're for. How can I
> decipher them? Just trial and error?
"STA" reports a status (whether the device is on or off). _ROM is mentioned in 
the ACPI Spec (http://www.acpi.info/spec.htm) and returns the Video BIOS.

> Maybe I need to somehow configure X to tell the nvidia driver to ignore the
> integrated GPU device so that it configures the discrete device to use the
> laptop LCD. Or is there some other reason that nvidia isn't letting me
> assign that monitor to the discrete device?
Again, try https://wiki.archlinux.org/index.php/Dell_Studio_XPS_13

Regards,
Peter