Help? Xinerama with two cards

[David Iannucci]

Thanks for the responses Felix and Dave.  I will rearrange the
quotations below a bit:

> I find config files easier to work with than xrandr. You might
> want to try. My last dual head session with Intel and Radeon left
> these behind:

Thanks... checked these out. I took your advice and did my best to
craft an xorg.conf based on your examples and other documentation I
found, but nothing is happening on my second monitor (this doesn't
surprise me much).

I have read a few times now that Xorg is not supposed to need config
files any more - that it's mostly self-configuring, and xrandr is the
way to go to manipulate your display if you need to, and this appeals to
me a lot..... I never was very comfortable with xorg.conf :-)

Please recall that what I'm trying to do is drive two heads off of
_two different_ GPUs. I was told a few years ago by someone who
seemed to know what he was talking about that X just doesn't DO that
(at the time). My understanding was that recent changes in xrandr 1.4
would allow it.

> KDE 4.11 has KScreen, which is supposed to provide easy management of
> multi screen configuration.

Trying to go more minimalist, not more bloatist :-) :-)

So here's the nutshell of what I'm left with:

Xrandr shows me 3 outputs: VGA1, HDMI2, and DP1 (with only VGA1
"connected", even though 2nd monitor is plugged into DVI port of
Radeon). This DP1 original fooled me into thinking that the 2nd port on
my Radeon card was a DisplayPort, but close examination shows it to be
HDMI. So "DP1" is confusing. Between the 2 GPUs there are 4 output ports
(two on each), so the fact that xrandr shows me 3 is a hint that my
kernel is.... ok? But why not four?

Finally, perhaps I failed to mention before that sometimes partial
chunks of output (system boot messages), or a "distortion pattern" (?)
appear on monitor 2. This is encouraging to me, but I don't know if it's
really good news.

Anyone who missed my original post can look below to see that
xrandr --listproviders gives a sensible output.

Hoping that this, my last post on the topic before giving up and
probably buying an HDMI-VGA adaptor, will attract the attention of
someone who knows how to troubleshoot it.

At the very least, I would really like to know the truth about
(1) whether X.org has never, historically, been able to drive a
dual-head setup off of two GPUs, and (2) whether xrandr 1.4 is really
supposed to remedy this. Thanks a lot.

Dave



On Tue, Jul 2, 2013, at 13:52, Felix Miata wrote:
> On 2013-07-02 13:21 (GMT-1000) David Iannucci composed:
> 
> > David Iannucci wrote:
> 
> >> I'm trying to set up a xinerama arrangement over two graphics cards
> >> (Intel + Radeon), taking advantage of xrandr 1.4's features which
> >> (I understand, perhaps mistakenly, to) support this configuration.
> >> I'm running xorg server 1.13.4 on Gentoo. It might be useful for
> >> you to know in addition that I'm running a barebones KDE 3.5.10
> >> desktop on it.
> 
> >> If I do --listproviders, I get both cards listed:
> 
> >> # xrandr --listproviders
> >> Providers: number : 2
> >> Provider 0: id: 0x87 cap: 0xb, Source Output, Sink Output, Sink
> >> Offload crtcs: 3 outputs: 3 associated providers: 0 name:Intel
> >> Provider 1: id: 0x57 cap: 0xd, Source Output, Source Offload, Sink
> >> Offload crtcs: 6 outputs: 2 associated providers: 0 name:radeon
> 
> >> However no use of --setprovideroutputsource or
> >> --setprovideroffloadsink (with arguments "0 1" or "1 0") will do
> >> what I want.  Am I completely misunderstanding this?
> 
> >> One monitor is connected to VGA output of integrated Intel GPU, and
> >> the other to DVI output of Radeon (HD 7570) PCI card.  I think kernel
> >> stuff is set up properly:
> 
> >> # lsmod | grep radeon
> >> radeon                858404  1
> >> cfbfillrect             3714  2 i915,radeon
> >> cfbimgblt               2039  2 i915,radeon
> >> ttm                    58739  1 radeon
> >> cfbcopyarea             3350  2 i915,radeon
> >> drm_kms_helper         26569  2 i915,radeon
> >> fb                     33637  6
> >> i915,fbcon,drm_kms_helper,radeon,softcursor,bitblit
> >> backlight               4248  2 video,radeon
> 
> >> Please document this functionality more clearly! Any help with this
> >> will be much appreciated. I can try to end-run the problem by asking
> >> my boss to buy me an HDMI-capable monitor, to plug into the second
> >> port of Intel card, but I've already got the Radeon, and I'd rather
> >> try to figure this out before throwing money at it :-) Thx.
> 
> > So.... I've left this sit for a while and it doesn't look like there's
> > anyone here able to help.
> 
> > Is there a better place to ask for help with xrandr? Have I left out
> > some crucial information?
>