hybrid-graphics-linux team mailing list archive

[Michael Rodríguez-Torrent <mrtorrent@xxxxxxxxx>]

Bruno and Peter,

Thank you for taking the time to reply earlier. I didn't have time to work
on this for a while, but I've done a bit more research along the lines you
both suggested.

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)" (?)

So, the discrete card is always running and somehow gets configured with a
(bogus?) display, while the integrated card gets the laptop LCD.

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.
The computer will respond to keyboard input, however. I've also tried using
the "ConnectedMonitor" option to force the discrete card to use a DFP
instead of a CRT, and I've also tried explicitly configuring an X screen in
xorg.conf to use the dedicated GPU device with the LCD monitor. All of this
still results in a black/off screen upon starting X. Is there a reason that
the card wouldn't be driving the display? Is there something more I can do
to tie them together?

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?

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?

Thanks again for any suggestions,
Michael

On Tue, Jul 17, 2012 at 4:40 PM, Lekensteyn <lekensteyn@xxxxxxxxx> wrote:

> On Tuesday 17 July 2012 15:11:55 Michael Rodríguez-Torrent wrote:
> > Hi Bruno, thank you for getting back to me. That's frustrating to hear
> that
> > integrated nVidia can't be handled in the same way as Intel. Will
> bbswitch
> > work to turn off the discrete card, however? Or should I use the
> acpi_call
> > module with the call I mentioned (described here:
> >
> http://luizfar.wordpress.com/2010/06/29/how-to-switch-off-xps1340-discrete-v
> > ideo-card-on-linux/ )?
> You'd better not use acpi_call if bbswitch works, acpi_call does not
> surivive
> suspend for example.
>
> > Also, are there known ways to force X to use the discrete card full-time
> > rather than the integrated chip? Do you know if there's some way I can
> > research ACPI calls or whatever it may take to do this? I'm not quite
> sure
> > where to begin.
> **Some** machines have an ACPI method for switching card for the next boot,
> for example, the ASUS Eee PC 1015PN:
>
> https://wiki.archlinux.org/index.php/ASUS_Eee_PC_1015pn#nVidia_ION_2_with_Optimus
>
> These are, however, very rare cases. More often, you will find a BIOS
> option on
> enterprise laptops (Lenovo ones) for selecting a card. but the majority of
> the
> people won't have any option at because it saves the manufacturer costs.
>
> So, you may dig in your ACPI tables, but there is a little chance that you
> are
> really that lucky to find something that allows you to use the discrete
> card
> only. (I am ignoring PRIME in this story for now as you cannot use it with
> the
> proprietary nvidia driver and besides that, it is not ready).
>
> Regards,
> Peter
>