How to setup independent screens with the Intel driver?

[Chris Wilson]

On Fri, Oct 30, 2015 at 06:17:50PM +0100, Boszormenyi Zoltan wrote:
> 2015-10-30 18:03 keltezéssel, Chris Wilson írta:
> > On Fri, Oct 30, 2015 at 05:56:35PM +0100, Boszormenyi Zoltan wrote:
> >> 2015-10-30 17:46 keltezéssel, Boszormenyi Zoltan írta:
> >>> 2015-10-30 17:36 keltezéssel, Chris Wilson írta:
> >>>> On Fri, Oct 30, 2015 at 04:58:49PM +0100, Boszormenyi Zoltan wrote:
> >>>>> Section "Device"
> >>>>>         Identifier "Intel0"
> >>>>>         Driver     "intel"
> >>>>>         BusID      "PCI:0:2:0"
> >>>>>         Screen     0
> >>>>>         Option      "AccelMethod"  "sna"
> >>>>>         Option     "Monitor-LVDS1" "LVDS1"
> >>>> Option     "ZaphodHeads" "LVDS1"
> >>>>
> >>>>>         Option     "TearFree" "on"
> >>>>> EndSection
> >>>>>
> >>>>> Section "Device"
> >>>>>         Identifier "Intel1"
> >>>>>         Driver     "intel"
> >>>>>         BusID      "PCI:0:2:0"
> >>>>>         Screen     1
> >>>>>         Option      "AccelMethod"  "sna"
> >>>>>         Option     "Monitor-VGA1" "VGA1"
> >>>> Option     "ZaphodHeads" "VGA1"
> >>>>
> >>>>>         Option     "TearFree" "on"
> >>>>> EndSection
> >>>> -Chris
> >>> I tried adding the ZaphodHeads option to the device sections before.
> >>> It didn't work. The driver throws an error:
> >>>
> >>> [3114226.306] (II) intel(0): Using Kernel Mode Setting driver: i915, version 1.6.0 20150522
> >>> [3114226.307] (II) intel(1): Using Kernel Mode Setting driver: i915, version 1.6.0 20150522
> >>> [3114226.307] (--) intel(0): Integrated Graphics Chipset: Intel(R) Pineview G
> >>> [3114226.308] (--) intel(0): CPU: x86-64, sse2, sse3, ssse3; using a maximum of 2 threads
> >>> [3114226.308] (==) intel(0): Depth 24, (--) framebuffer bpp 32
> >>> [3114226.308] (==) intel(0): RGB weight 888
> >>> [3114226.308] (==) intel(0): Default visual is TrueColor
> >>> [3114226.308] (**) intel(0): Option "AccelMethod" "sna"
> >>> [3114226.308] (**) intel(0): Option "ZaphodHeads" "LVDS1"
> >>> [3114226.308] (**) intel(0): Option "TearFree" "on"
> >>> [3114226.309] (EE) intel(0): LVDS1 is an invalid output for screen (pipe) 0
> >> It seems the device pipe and screen matching doesn't work properly.
> >> The driver seems to be assuming that its pipe numbers always match
> >> the same X screen numbers.
> > Assuming? That's how I documented it.
> > -Chris
> 
> "man intel" on Fedora 22 doesn't says anything like that. Where is it documented?

Apparently in my imagination. I could have sworn that I wrote about the
relationship between the Screen number and the CRTC it was assigned and
how you needed to look at the xrandr output to work out possible
arrangements. Probably lost in some bugzilla.
 
> In my case with this particular POS machine, the intended primary display,
> the built-in LVDS with a touchscreen attached is apparently wired to pipe 1.
> 
> With this driver behaviour, I can't configure it to be kept as the default :0.0 screen
> if an external display is plugged in. Can this behaviour be changed?

It would need another user parameter. There are several technical
limitations that make automatic assignment difficult. So try

commit 94d271b239d358f71ae0bcfcc31422a569d73d41
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Fri Oct 30 18:07:37 2015 +0000

    sna: Allow pipes to be manually assigned to ZaphodHead
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre