[enhancement] Mir lacks a software rendering backend

Reported by Daniel van Vugt on 2013-02-08
62
This bug affects 9 people
Affects Status Importance Assigned to Milestone
Mir
High
Unassigned
Unity System Compositor
Medium
Unassigned
XMir
Medium
Chris Halse Rogers

Bug Description

As always, it's a critical requirement for Ubuntu to be able to render the same thing on any machine, regardless of the availability of hardware acceleration. Would this mean fbdev?

Daniel van Vugt (vanvugt) wrote :

See also: bug 1118909

Chris Halse Rogers (raof) wrote :

I'm not sure if we actually *do* need to be able to run without hardware acceleration.

We certainly need, *in Ubuntu*, to handle the case where there's a problem with the graphics driver configuration or whatever. It's less clear to me that the solution to this is for Mir to handle it.

Daniel van Vugt (vanvugt) wrote :

I think being able to run Ubuntu in a VM is important. It would be a big call to drop that ability.

Daniel van Vugt (vanvugt) wrote :

Please note: It would probably be a bad idea to resolve this bug before bug 1118909 is addressed.

information type: Proprietary → Public
Changed in mir:
status: New → Confirmed
Robert Ancell (robert-ancell) wrote :

Setting to wishlist - there is not a requirement to run without EGL support that I know of.

Changed in mir:
status: Confirmed → Triaged
importance: High → Wishlist
Daniel van Vugt (vanvugt) wrote :

I think Medium is a better compromise. You can't make the unity system compositor the default one for Ubuntu unless it works in VMs too. So it's critical in the long run, but only medium now because the Mir-based system compositor won't be default for a while.

Changed in mir:
importance: Wishlist → Medium
kevin gunn (kgunn72) wrote :

just bumping priority on this.

Changed in mir:
importance: Medium → High
assignee: nobody → Daniel van Vugt (vanvugt)
summary: - System compositor lacks a software rendering backend
+ Mir lacks a software rendering backend
Changed in unity-system-compositor:
status: New → Triaged
importance: Undecided → Medium

I don't see anything specific to unity-system-compositor here... ?

Changed in unity-system-compositor:
status: Triaged → Incomplete
Robert Ancell (robert-ancell) wrote :

The requirement is both unity-system-compositor and XMir can run with software rendering. The solution is for Mir to implement this and both u-s-c and XMir to make use of this functionality.

Changed in unity-system-compositor:
status: Incomplete → Triaged
Daniel van Vugt (vanvugt) wrote :

OK, but no change whatsoever is required in unity-system-compositor, AFAIK.

Some change will be required in XMir though. We now have the XMir project for that.

Changed in xmir:
status: New → Triaged
assignee: nobody → Chris Halse Rogers (raof)
Kai Mast (kai-mast) wrote :

What about LLVMpipe? This should really be handled by mesa.

Daniel van Vugt (vanvugt) wrote :

Yes, using LLVMpipe is the plan. But LLVMpipe needs a screen to render to. So Mir needs to be modified to provide that.

kevin gunn (kgunn72) wrote :

not critical for 13.10

Changed in xmir:
importance: Undecided → Medium
Bryan Quigley (bryanquigley) wrote :

Please not fbdev. Most recent article I could find on this: http://www.phoronix.com/scan.php?page=news_item&px=MTM5MDc

Ideally we would be moving to a KMS based VESA/EUFI driver.

Daniel van Vugt (vanvugt) wrote :

Bryan,

Thanks for pointing that out. It led me to find this, which would certainly be preferable if it's mature enough;
http://lists.freedesktop.org/archives/dri-devel/2013-January/034058.html

Not sure. I'm not working on this task yet.

Daniel van Vugt (vanvugt) wrote :

It seems KMS support for VBE is effectively non-existent (never landed and was never finished anyway). Red Hat too, are planning for vesa/fbdev being their fallback:

https://lists.fedoraproject.org/pipermail/devel/2013-August/188429.html

No one wants to use fbdev, but it is apparently still the only software rendering interface to that works /everywhere/. I hope to be proven wrong :(

Bryan Quigley (bryanquigley) wrote :

Seems like it's still being worked on (or at least something similar, by the same author), and maybe pushing for mainline in 3.12.
http://www.phoronix.com/scan.php?page=news_item&px=MTQ1MTM
http://lists.freedesktop.org/archives/dri-devel/2013-September/044638.html

summary: - Mir lacks a software rendering backend
+ [feature] Mir lacks a software rendering backend
tags: added: feature
summary: - [feature] Mir lacks a software rendering backend
+ [enhancement] Mir lacks a software rendering backend
tags: added: enhancement
removed: feature
kevin gunn (kgunn72) wrote :

QA is still interested in rendering without gpu

kevin gunn (kgunn72) wrote :

hint, this would be a great community contribution

Changed in mir:
assignee: Daniel van Vugt (vanvugt) → nobody
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