[Nouveau] regression? no more separate xscreens

[Ilia Mirkin]

On Wed, May 10, 2017 at 4:20 AM, Sampsa Riikonen <sampsa.riikonen at iki.fi> wrote:
> Dear Devs,
>
> The support for multiple xscreens (i.e. no xinerama, just separate :0.0 and
> :0.1 displays) in nouveau is broken.

Here's a free piece of advice - before declaring things as broken,
consider the possibility, remote though it might be, that you're doing
something that's off. It would definitely avoid me having an
unpleasant taste in my mouth as I still attempt to help you.

> https://nouveau.freedesktop.org/wiki/MultiMonitorDesktop/
>
> *** xorg.conf ***
>
> Section "ServerLayout"
>     Identifier  "Layout0"
>     # Option      "Xinerama" "off"  # tried commenting & uncommenting this
> one
>     # Option      "Clone"    "off"
>     # You would need one screen for each monitor
>     Screen   0  "Screen0"
>     Screen   1  "Screen1"  RightOf "Screen0"
> EndSection
>
> Section "Device"
>     Identifier  "Device0"
>     Driver      "nouveau"
>     # Actual PCI location of first card/gpu
>     BusID       "PCI:1:0:0"
>     # Actual connector - as reported by /sys/class/drm/card0-xx (except
> HDMI, which is HDMI-x instead of HDMI-A-x)
>     Option      "ZaphodHeads" "DVI-I-1"
>     # Screen number for that PCI device, i.e. 0, 1, etc.
>     Screen      0
> EndSection
>
> Section "Device"
>     Identifier  "Device1"
>     Driver      "nouveau"
>     # Actual PCI location of second card/gpu
>     BusID       "PCI:2:0:0"
>     # Actual connector - as reported by /sys/class/drm/card0-xx (except
> HDMI, which is HDMI-x instead of HDMI-A-x)
>     Option      "ZaphodHeads" "DVI-I-2"
>     # Screen number for that PCI device, i.e. 0, 1, etc.
>     Screen      1

You probably wanted 0 here, not 1. It should be 1 for the second
screen *of the gpu*, not overall.

> EndSection
>
> Section "Screen"
>     Identifier  "Screen0"
>     Device      "Device0"
> EndSection
>
> Section "Screen"
>     Identifier  "Screen1"
>     Device      "Device1"
> EndSection
>
> *** Xorg.0.log ***
>

[...]

> [     6.947] (II) LoadModule: "nouveau"
> [     6.947] (II) Loading /usr/lib/xorg/modules/drivers/nouveau_drv.so
> [     6.947] (II) Module nouveau: vendor="X.Org Foundation"
> [     6.947]    compiled for 1.18.1, module version = 1.0.12
> [     6.947]    Module class: X.Org Video Driver
> [     6.947]    ABI class: X.Org Video Driver, version 20.0

[...]

> [     6.950] (II) [drm] nouveau interface version: 1.3.1
> [     6.950] (EE) Unknown chipset: NV117
> [     6.950] (II) [drm] nouveau interface version: 1.3.1
> [     6.950] (EE) Unknown chipset: NV117
> [     6.950] (II) [drm] nouveau interface version: 1.3.1
> [     6.950] (EE) Unknown chipset: NV117
> [     6.950] (II) [drm] nouveau interface version: 1.3.1
> [     6.950] (EE) Unknown chipset: NV117
> [     6.950] (II) [drm] nouveau interface version: 1.3.1
> [     6.951] (EE) Unknown chipset: NV117
> [     6.951] (II) [drm] nouveau interface version: 1.3.1
> [     6.951] (EE) Unknown chipset: NV117
> [     6.951] (II) [drm] nouveau interface version: 1.3.1
> [     6.951] (EE) Unknown chipset: NV117
> [     6.951] (II) [drm] nouveau interface version: 1.3.1
> [     6.951] (EE) Unknown chipset: NV117

This really didn't seem to you like a hint that something in your
configuration was off?

> [     6.951] (II) intel(G0): Using Kernel Mode Setting driver: i915_bpo,
> version 1.6.0 20160425
> [     6.951] (II) intel(G0): SNA compiled: xserver-xorg-video-intel
> 2:2.99.917+git20160325-1ubuntu1.2 (Timo Aaltonen <tjaalton at debian.org>)
> [     6.951] (II) intel(G0): SNA compiled for use with valgrind
> [     6.952] (II) modeset(0): using drv /dev/dri/card0
> [     6.952] (II) modeset(G1): using drv /dev/dri/card2
> [     6.952] (WW) Falling back to old probe method for fbdev
> [     6.952] (II) Loading sub module "fbdevhw"
> [     6.952] (II) LoadModule: "fbdevhw"
> [     6.952] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
> [     6.952] (II) Module fbdevhw: vendor="X.Org Foundation"
> [     6.952]    compiled for 1.18.4, module version = 0.0.2
> [     6.952]    ABI class: X.Org Video Driver, version 20.0
> [     6.952] (WW) Falling back to old probe method for vesa
> [     6.965] (II) modeset(0): Creating default Display subsection in Screen
> section
>         "Screen0" for depth/fbbpp 24/32

So ... you see that the modesetting driver is being used for the
nvidia gpu, and yet no alarm bells go off, "maybe something is wrong"?

The issue is that you're trying to use nouveau 1.0.12 with a GM107
GPU, while support in the DDX for such GPUs was only added in 1.0.14.