Zaphod mode with the Open Source Driver?

[daveh]

Firstly, sorry if this is covered somewhere and I've missed it.

Has anyone had success configuring any of the the recent open source ATI drivers for Zaphod (dual independent head) mode?

If so - any pointers?

[duby229]

Firstly, sorry if this is covered somewhere and I've missed it.

Has anyone had success configuring any of the the recent open source ATI drivers for Zaphod (dual independent head) mode?

If so - any pointers?

It was working a while ago, but it hasnt worked in at least 4 months for me. I wish some developers would try to spend some time cleaning up that code and making it work well again. In my opinion it has every benefit over every other multimonitor mode. The only drawback I can think of is that you cant drag a window from one screen to the other, short of that it does everything I want better and simpler.

[Chewi]

It was working a while ago, but it hasnt worked in at least 4 months for me. I wish some developers would try to spend some time cleaning up that code and making it work well again. In my opinion it has every benefit over every other multimonitor mode. The only drawback I can think of is that you cant drag a window from one screen to the other, short of that it does everything I want better and simpler.

I totally echo that. It's the one damn thing that's holding me back from switching. I tried it again just now with linux-next-20091202 and the latest from drm-radeon-testing. Still no dice. I have a bug report about it here.

https://bugs.freedesktop.org/show_bug.cgi?id=24523

[Luzipher]

Hm, for me Zaphod mode is working almost flawlessly on two rv770's (HD4870) with 3 screens. The only bug I encounter sometimes is #25311, but I'm not even sure it's radeon specific ...


As you ask for pointers ... well, i have two device sections in my xorg.conf ... that's pretty much all I did. I'm running on KMS on a drm-next kernel (about 2 weeks old, 2.6.32-rc8) with VGA Arbitration enabled and recent git DDX (xf86-video-ati).

You can find my somewhat cluttered xorg.conf here: http://pastebin.com/f5fdad007

[xeros]

Firstly, sorry if this is covered somewhere and I've missed it.

Has anyone had success configuring any of the the recent open source ATI drivers for Zaphod (dual independent head) mode?

If so - any pointers?

Could you tell something more about this mode?
Can it be used to start two Xservers for one card or just to separate screens on one Xserver?

I'm using dual seat with two (R3xx) graphic cards (AGP Radeon 9600 and PCI-E Radeon x300) on two Xservers stared by KDM - everything working perfectly on Kubuntu 9.04 and 9.10 but there's one screen for one card.

[Chewi]

It's for separate screens on one server. Thinking about how the configuration is laid out, it may work across more than one card but I'm not sure.

Luzipher, I noticed that bug while replying to this thread and it did get me wondering. I haven't enabled the VGA Arbitration stuff, maybe that's what I need. Otherwise I suspect a bug in the output enumeration of some cards. My bug report gives a rather confusing account of how it seems to mix up the DIN output with my DVI outputs.

[Chewi]

Hmm seems VGA Abitration is already enabled in the kernel but I think it needs xorg-server-1.7. I've stuck with 1.6 because fglrx doesn't support 1.7 yet and downgrading (if it doesn't work out) would be a total bitch.

[agd5f]

My bug report gives a rather confusing account of how it seems to mix up the DIN output with my DVI outputs.

It's not mixing it up, the DIN port is a valid output. This is one of the problems with zaphod, how do you pick which outputs get assigned to which instances of the driver if you have more than two outputs but only two display controllers. There's not a good way.

[Chewi]

Just tried with xorg/server-1.7.3 anyway. Still no joy. And downgrading was indeed a total bitch.

I didn't notice till I tried it that Luzipher actually has two cards. That's probably why it works for him.

It's not mixing it up, the DIN port is a valid output. This is one of the problems with zaphod, how do you pick which outputs get assigned to which instances of the driver if you have more than two outputs but only two display controllers. There's not a good way.

I didn't mean that DIN wasn't a valid output but shouldn't the names you give in xorg.conf be used to determine which outputs you're actually talking about? I have found that the order you specify them in at least seems to make some difference. But even when the log shows that it is correctly matching up each output with each monitor section, it still doesn't work.

[agd5f]

I didn't mean that DIN wasn't a valid output but shouldn't the names you give in xorg.conf be used to determine which outputs you're actually talking about? I have found that the order you specify them in at least seems to make some difference. But even when the log shows that it is correctly matching up each output with each monitor section, it still doesn't work.

zaphod doesn't work like xrandr. You can't pick arbitrary outputs. The driver just grabs the first two outputs and assigns one to each instance of the driver. If you have more than two outputs the remaining outputs are unavailable with zaphod.