Bug#396193: [Yaird-devel] Bug#396193: Patch to recognize openfirmware drivers

[Sven Luther]

On Fri, Mar 30, 2007 at 10:53:37PM +0200, Jonas Smedegaard wrote:
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> Sven Luther wrote:
> > On Fri, Mar 30, 2007 at 09:24:25PM +0200, Jonas Smedegaard wrote:
> 
> >> Bernhard R. Link wrote:
> >>
> >>> Attached patch teaches yaird to recognize openfirmware devices,
> >>> as they appear in linux 2.6.18.
> >>>
> >>> This makes my sparc with sbus devices work again with yaird and in
> >>> theory it should also make it not choke on ebus devices the bugreport
> >>> I'm sending this to is about.
> >> Thanks alot for your work - and sorry for my late response.
> >>
> >> Unfortunately, it seems to me that your patch will interfere with
> >> PowerPC machines, that also use OpenFirmware. Looking briefly on a
> >> Macintosh at hand, it contains devspec files in sysfs too, but not the
> >> modules.ofmap that your patch seems to rely on.
> >>
> >> Could anyone check if I am right - and perhaps figure out a sane way to
> >> deal with the different openfirmware implementations?
> > 
> > The future of powerpc plateform drivers, with the move to arch=powerpc, and
> > everything relying on an openfirmware-like device tree, is to go the
> > plateform_of way. This does include the powermacs, which is the primary
> > development plateform of benjamin herrenschmidt, among others, who was
> > involved in the openfirmware driver move.
> > 
> > As thus, adding support for the openfirmware plateform devices is needed to
> > continue to have hotplug support for those devices, and vital for yaird.
> 
> Thanks for the detailed info, Sven.
> 
> I did notice shortly after firing off that email that indeed the ofmap
> file is present for a 2.6.18 kernel, only not for that ancient 2.6.8
> kernel I was looking at at first.
> 
> This raises another question: It seems to me that this patch will fail
> for kernels that offers devspec in sysfs but does not ship with a
> modules.ofmap file.
> 
> If so, applying this patch will cause yaird to stop working on older
> kernels that worked before.

Well, you may disagree, and we almosted fighted in erkelenz over this, but if
someone is using an ancient kernel not in current etch or lenny, then he
should use the version of yaird which goes with it, namely the sarge version.

It is very probably that the absence of this patch will break yaird in lenny
even, or also the etch upgrade kernel at mid-live we have planned.

Furthermore, ancient kernels are no more supported in debian/etch anyway, due
to udev if nothing else, and the upgrade path does recomend upgrading the
kernel early on.

So, if you want to use a pre-etch kernel, then you should use the accompanying
pre-etch yaird.

Friendly,

Sven Luther