Dropping compat from master-compat

Dropping compat from master-compat

[Pekka Paalanen]

Hi,

the master-compat branch in nouveau/linux-2.6 kernel tree has got a
little bit out of hand. Distributions are packaging that, and I
cannot know if they warn their users well enough about the hazards
of using backported DRM (see:
http://nouveau.freedesktop.org/wiki/UpstreamKernelIssues ).

I originally intended master-compat as an easy way of installing
the Nouveau flavour of DRM modules even on older kernels, because
I felt I should share my helper scripts and patches. However, I
never intended to do real kernel bug tracking, that was the users'
responsiblity. I didn't bring that fact forward well enough and
I'm sorry about that. Now I know why no-one else has done this
for any of the other drivers. It's drm.git all over again.

Also, running the Nouveau DRM with an older kernel is of questionable
value when it comes to testing. Why support something you do not
really support?

Therefore, I will drop compatibility code from master-compat branch,
and I will add a compile time check for the kernel version. The
master-compat branch will be just like the master branch, except it
contains the out-of-tree build scripts. This will force users to
follow very closely the official RC and release kernels.

If you want to use the latest Nouveau DRM with an older kernel,
you get to do the backporting and kernel bug tracking yourself.
This is the distributions' responsibility in general.

Couple of things to remember:
- there still are no releases of any Nouveau code
- the recommended way to build Nouveau DRM is to build the
whole kernel from the same tree.

Sorry for the trouble, but we need to look forward.

-- 
Pekka Paalanen
http://www.iki.fi/pq/

Re: Dropping compat from master-compat

[Andreas Radke]

Am Wed, 9 Sep 2009 20:51:36 +0300
schrieb Pekka Paalanen <pq-X3B1VOXEql0@public.gmane.org>:

> Hi,
> 
> the master-compat branch in nouveau/linux-2.6 kernel tree has got a
> little bit out of hand. Distributions are packaging that, and I
> cannot know if they warn their users well enough about the hazards
> of using backported DRM (see:
> http://nouveau.freedesktop.org/wiki/UpstreamKernelIssues ).
> 
> I originally intended master-compat as an easy way of installing
> the Nouveau flavour of DRM modules even on older kernels, because
> I felt I should share my helper scripts and patches. However, I
> never intended to do real kernel bug tracking, that was the users'
> responsiblity. I didn't bring that fact forward well enough and
> I'm sorry about that. Now I know why no-one else has done this
> for any of the other drivers. It's drm.git all over again.
> 
> Also, running the Nouveau DRM with an older kernel is of questionable
> value when it comes to testing. Why support something you do not
> really support?
> 
> Therefore, I will drop compatibility code from master-compat branch,
> and I will add a compile time check for the kernel version. The
> master-compat branch will be just like the master branch, except it
> contains the out-of-tree build scripts. This will force users to
> follow very closely the official RC and release kernels.
> 
> If you want to use the latest Nouveau DRM with an older kernel,
> you get to do the backporting and kernel bug tracking yourself.
> This is the distributions' responsibility in general.
> 
> Couple of things to remember:
> - there still are no releases of any Nouveau code
> - the recommended way to build Nouveau DRM is to build the
> whole kernel from the same tree.
> 
> Sorry for the trouble, but we need to look forward.
> 

Sorry to hear that. 

My distribution does not allow any backports to the main packages
(e.g libdrm and kernel) . We ship almost everything in the latest stable
released version plain vanilla. If you want us to keep shipping nouveau
driver please make sure we can always build against the latest stable
released kernel and libdrm.

I know there's no released nouveau driver out so far but if you want a
wide user range make sure it can be build on top of the latest stable
stuff distributions have in their repos.

-Andreas Radke
Arch Linux package maintainer

Re: Dropping compat from master-compat

[Pekka Paalanen]

On Wed, 9 Sep 2009 22:02:13 +0200
Andreas Radke <a.radke-KvP5wT2u2U0@public.gmane.org> wrote:

> Am Wed, 9 Sep 2009 20:51:36 +0300
> schrieb Pekka Paalanen <pq-X3B1VOXEql0@public.gmane.org>:
> 
> > Therefore, I will drop compatibility code from master-compat branch,
> > and I will add a compile time check for the kernel version. The
> > master-compat branch will be just like the master branch, except it
> > contains the out-of-tree build scripts. This will force users to
> > follow very closely the official RC and release kernels.
> > 
> > If you want to use the latest Nouveau DRM with an older kernel,
> > you get to do the backporting and kernel bug tracking yourself.
> > This is the distributions' responsibility in general.
> 
> My distribution does not allow any backports to the main packages
> (e.g libdrm and kernel) . We ship almost everything in the latest stable
> released version plain vanilla. If you want us to keep shipping nouveau
> driver please make sure we can always build against the latest stable
> released kernel and libdrm.

But you were already using a backport. What is the difference here?
Because up to now master-compat was just that, a backport.

The kernel bugs I referred to made using Nouveau with 2.6.30.x, x < 5
kernels quite dangerous, and 2.6.31 is not out yet. How did you manage
that before 2.6.30.5 came out?

And with libdrm, you were just lucky. There have been times when no
released libdrm contained the required Nouveau code, and no libdrm
releases will be made due to Nouveau until the DRM driver has been
officially released in a Linux kernel. It may still bite you one
day. Nouveau code should not even be a part of libdrm releases yet,
that is why the --enable-nouveau-experimental-api switch exists,
so that libdrm packagers would not need to delete the files while
packaging.

It is not in any way friendly to those who want to distribute
Nouveau, but that can't be helped, really.

> I know there's no released nouveau driver out so far but if you want a
> wide user range make sure it can be build on top of the latest stable
> stuff distributions have in their repos.

That requires a dedicated person for watching kernel bugs. To my
understanding distributions have to do this routinely. Nouveau
developers certainly do not have the time to do that. And it
wasn't really done for master-compat. Other people had to come in
and poke me and say I suck.

It would be nice, if you shipped nouveau, because it means more
testing. But if you are testing with "bad" kernels, it is not
really that useful.

All that this change of master-compat really means, is that *I*
will not maintain backwards compatibility anymore. I have other
plans. If someone else wants to step up, he or she can. But
developers will always be prejudiced against bug reports
from backported modules, since that is not supported.

Sorry, but I do not see an easy solution. Sometimes I wonder
myself how testing needs distribution which depends on a release
which depends on testing it first. Apparently we just have to
settle with less testing before a release. A universal problem.

-- 
Pekka Paalanen
http://www.iki.fi/pq/

Re: Dropping compat from master-compat

[Pekka Paalanen]

On Wed, 9 Sep 2009 20:51:36 +0300
Pekka Paalanen <pq-X3B1VOXEql0@public.gmane.org> wrote:

> Therefore, I will drop compatibility code from master-compat branch,
> and I will add a compile time check for the kernel version. The
> master-compat branch will be just like the master branch, except it
> contains the out-of-tree build scripts. This will force users to
> follow very closely the official RC and release kernels.

It is done. The snapshot is updated.

I did not put any deliberate kernel version checks in place yet.
That may follow later.

$ git diff --stat master..master-compat
 README-nouveau   |   17 +++++++++
 nouveau/DEPENDS  |   25 +++++++++++++
 nouveau/Makefile |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 142 insertions(+), 0 deletions(-)

-- 
Pekka Paalanen
http://www.iki.fi/pq/