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Intel Rejects Supporting Ubuntu's XMir
An anonymous reader writes "Just days after Intel added XMir support to their Linux graphics driver so it would work with the in-development the X11 compatibility layer to the Mir display server premiering with Ubuntu 13.10, Intel management has rejected the action and had the XMir patch reverted. There's been controversy surrounding Mir with it competing with Wayland and the state of the display server being rather immature and its performance coming up short while it will still debut in Ubuntu 13.10. Intel management had to say, "We do not condone or support Canonical in the course of action they have chosen, and will not carry XMir patches upstream." As a result, Canonical will need to ship their own packaged version of the Intel (and AMD and Nouveau drivers) with out-of-tree patches."
Though Intel will be open to an alternative to X11 they are in no way obliged to carry an immature release just because Canonical wants to push theirs.
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When will Linux finally use standard ABIs and APIs for drivers just like very other OS on the planet?
Why can't you just use one driver written a few years ago and use it universally across all distros due to this? The other free BSDs have this and you can install the extra compat libraries to accomplish this. I guess RMS thinks that is oppressive and wants opensource hardware even though patent holders from the likes of the h.264 consortorium forbid it!
Before I get flamed remember the article mentioned ATI and NVidia drivers as well so Intel is not the asshole here. Rather they different kernels and distros being redone requiring new QA and recompiling with every release.
There is a reason many old time linux users like myself only run CentOS in a VM Now. It is because Redhat provides ABIs and APIs that do not change for 5 years. Unfortunately it also means an out of date distro as well which is not fair to non server users (even a few server users who need a newer app or framework.)
http://saveie6.com/
I trust them more than Canonical, that's for sure.
Mother is the best bet and don't let Satan draw you too fast.
I'm honestly not super clear myself! But the DDX is, as I understand it, the in-Xorg portion of the graphics driver. So I guess it's not unreasonable that that component needs to know it's not got complete control of the hardware, as opposed to the Xorg-only case where it would have. Presumably it needs to proxy some operations through Mir (or Wayland, for XWayland) that it'd normally just set directly.
A *bit* like running X under X using Xnest or Xephyr, though I'd imagine it's less extreme than that (since those, I'd guess, have to issue X-level drawing commands to their host X server, whereas to get graphics under Wayland/Mir they'd just render to a memory buffer like any Wayland/Mir client).
All slightly speculative since I'm not familiar with the in-depth technical details!
So when Ubuntu 13.10 ships, it will force you to use XMir?
If so, thanks for the warning. The last thing I want to do is deal with an unstable graphics driver. It's taken years for X11 with NVidia drivers to get stable, and I don't want to touch XMir with someone else's 10-foot pole for until it's been in use for at least 2-3 years.
I do not fail; I succeed at finding out what does not work.
Canonical decided to write their own Mir display server instead of adopting the existing Wayland. They stated their reasons for doing so, but I'm not convinced they really had to start their own project instead of modifying Wayland.
It seems only fair to me that if Canonical wants to do their own thing, they'll have to put in the effort to maintain it. Because that is what this is about: Intel management decided that they're not going to pay their engineers to maintain code that benefits only Canonical.
I think Mir is a case study in how to correctly identify problems and then going about solving them all wrong.
See, the good thing about Wayland is, it does the right thing in having a limited scope. It aims to do one thing and do it well: provide an API for GUI clients to share buffers with a compositor.
And the problem with Wayland is, of course, that... it has a limited scope. Screen management? Input handling? Buffer allocation? "A modern desktop needs all that!" say the Ubuntu devs, and yeah, that's absolutely correct. "That's a client concern," say the Wayland devs, and guess what? From their point of view, that's correct too. (Although Wayland since started working on an input handling API.)
Now, the important thing to realize is, when the Wayland guys say that something is a client concern, as I understand, they don't necessarily mean the GUI applications, no. They mean the compositor.
Meaning that a whole lot of the stuff desktop shells rely on is, in fact, not provided by Wayland itself.
That's where Weston comes in: it's supposed to be an example (a "reference implementation", to use the designated words) of how to write a compositor. But... not necessarily in a way that meets the higher level needs of desktop shells. Unsurprisingly, both KDE and GNOME will be using their own compositors.
So basically, a whole lot of the desktop integration on top of Wayland will be, as it were, left as an exercise to the reader.
With all that in mind, I think the highest outcome end game is somewhat clear: frame-perfect rendering through the Wayland API of Mir-composited KDE/GNOME/Unity clients.
Or in other words, Mir should probably be a set of APIs to handle all the admittedly important desktop integration -- clipboard, multi-screen layout, input and gestures, systray/notification requests... -- with an optional and replaceable compositor thrown in.
All the points of contention that I know of, mainly that Canonical requires server-side buffer allocation (presumably for mobile ARM platforms) where Wayland does it client-side, could have been resolved with some diplomacy and a mutual willingness to reach a satisfactory compromise.
But instead, it looks like the report card is just going to say, "Doesn't play well with others." As usual. What a sad mess and wasted opportunity.
-- B.
This sig does in fact not have the property it claims not to have.
That was pretty off-topic, there AC. You even left us guessing about which part of hicksville you call home (Georgia perhaps?).
Crimey
More like disinterested third party sees which way the winds are blowing and decides to pull resources away from supporting what is going to be an also-ran. Intel has been a very good citizen where it comes to provided chipset and video driver support to the Linux community. They are still making drivers for X.org ( you know the display server people actually use ) and likely will develop drivers for Wayland.
Why you or anyone else ( who does not run Ubuntu ) would want them dividing their efforts a third way writing software that will only be useful to a tiny segment escapes me. Normally I am not anti-choice but the best outcome here is for MIR to go down in flames.
The one factor that has made desktop UNIX/Linux a reality is the near universality of X11. Despite all the toolkit and desktop environment / window manager fights X11 was something software devs could depend on being there. As far as end users some integration issues aside they could run multiple toolkits and other high level stuff when needed. It would be really hard though for users to efficiently run multiple display servers. The display server is pretty much a core platform component now. I honestly think MIR is a Cononical attempt to create a walled garden for their platform. It isn't about better software for them but control.
I am glad Intel is abandoning the platform; hopeful Cononical's garden will simple become a ghetto.
Then Ubuntu comes along and goes "NOOOO", and decides to do it differently.
yep, this is the way of Linux. You throw many different things at a wall and see which one sticks best. Then you standardise on that thing.
Too many people are just about bitching that one thing is better than another thing without any comprehension that this is the way FOSS systems evolve. I imagine (or would hope) that Wayland and XMir will stand on their own and one will become a dominant player over the other. Politics aside this is the way it should be. Unfortunately, once the politics and the 'my thing is better than yours' attitude gets involved, it makes dropping the poor version for the better one difficult - people try to maintain the poorer one regardless.
You see this in Openoffice v LibreOffice. Surely by now one of these would have their best bits of code migrated to the other so development and evangelism could focus efforts on just one product, but instead we still have the bitching about which one is better. (though maybe its just too soon for this example)
The multitude of audio systems and the failure of the FOSS community to standardize on one is one of the more frustrating failings of desktop Linux in my memory.
I can speculate a bit with things that sound plausible to me given my knowledge of the system - but I might still be a bit off target... Still, maybe it helps a little.
Mir and Wayland both expect their clients to just render into a buffer, which clients might do with direct rendering, in which case the graphics hardware isn't really hidden from the client anyhow. AFAIK it's pretty normal practice that there's effectively in-application code (in the form of libraries that are linked to) that understands how to talk directly to the specific hardware (I think this already happens under Xorg). The protocol you talk to Wayland (and Mir, AFAIK) isn't really an abstraction over the hardware, just a way of providing buffers to be rendered (which might, have just been filled by the hardware using direct rendering).
In this case Xorg is a client of Mir, so it's a provider of buffers which it must render. The X11 client application might use direct rendering to draw its window, anyhow. But the Xserver might also want to access hardware operations directly to accelerate something it's drawing (I suppose)... So the X server needs some hardware-specific DDX, since Mir alone doesn't provide a mechanism to do all the things it wants.
As for why the Intel driver then needs to be modified... I also understand that Mir has all graphics buffers be allocated by the graphics server (i.e. Mir) itself. Presumably Xorg would normally do this allocation (?) In which case, the Intel DDX would need modifying to do the right thing under Mir. The only other reason for modifying the DDX that springs to mind is that perhaps the responsibilities of a "Mir Client" divide between Xorg and *its* client, so this could be necessary to incorporate support for the "Mir protocol" properly. That's just hand-waving on my part, though...
Bonus feature - whilst trying to find out stuff, I found a scary diagram of the Linux graphics stack but my brain is not up to parsing it at this time of day:
http://en.wikipedia.org/wiki/File:Linux_Graphics_Stack_2013.svg