[Impact]
* libdrm versioning is a mess, and lying about the version will lead to all kinds of problems.
* Changes between 2.4.39 in precise/quantal and 2.4.43:
- some tiling changes for radeon SI and multisampled surfaces (SI support is not available on precise xserver, so this is harmless.)
- Adding PCI ID's for newer chipsets on radeon.
- Some fixes for intel, and adding support for newer chipsets.
- A few small nouveau fixes, and adding support for selecting kepler engines
- manpages no longer formatted with troff, using xml instead
- adding support for freedreno (disabled in our package)
- Exynos fixes (disabled too)
- A small omap fix, which the pandaboard ppa already included.
* Renaming libdrm hasn't worked correctly, it has been attempted before in LP #1086345
* Lying about version numbers will break, there is a version in x-updates ppa that's the same version as quantal, so doing an upload with a version that's lower than what's available in quantal will break for anyone that followed the steam install instructions.
* libdrm-nouveau1a should be patched in again, and re-enabled for precise and quantal.
- plymouth needs this on quantal and precise
- precise xserver and mesa require this, too
[Test Case]
* Testing should be performed on quantal, precise lts-quantal, and precise original stack, with intel, radeon and nouveau.
* Plymouth should still work correctly on precise and quantal with all the 3 kinds of cards
* system should boot correctly, xserver, compiz and opengl applications must still work.
[Regression Potential]
* I believe the regression potential is low, raring has been mostly on a stack similar to quantal for most of the release, with the bump to new mesa 9.1 only happening right
before final freeze, so a lot of testing has already been done.
* Old nouveau abi has not been tested however, with the plymouth update finally using the 'dumb' kms api instead of nouveau/intel/radeon directly.
* The core libdrm api hasn't been changed however, libdrm-nouveau1a was only using that subset.
* So if something breaks, it's likely going to be in a form similar to #1086345
* It would be very unlikely to introduce new crashes in opengl applications, or xserver
[Other Info]
* Provisional MRE granted, for updating libdrm in quantal and precise to the raring version.
[Original bug report]
For the lts-raring backports stack libdrm needs to be backported to quantal and precise. While the API is stable and I haven't noticed any new bugs being introduced, I fear that bumping the version number to beyond what quantal provides will make upgrading to quantal harder. Unfortunately, I think this is the only solution.
The ubuntu-x-swat/x-updates ppa was recommended to be enabled for steam, and was already providing a newer libdrm:
https://launchpad.net/~ubuntu-x-swat/+archive/x-updates/+packages
The only way out I see is removing libdrm from that ppa, pushing a newer libdrm version to precise, removing libdrm from that ppa, and make update-manager downgrade libdrm during an upgrade to quantal.
It seems that dh-exec is not actually used during llvm-3.2 build, so I dropped it as build-depends.