[patch] powerpc: add scanning of ebc bus to of_platform

[patch] powerpc: add scanning of ebc bus to of_platform

[Christian Krafft]

Subject: powerpc: add scanning of ebc bus to of_platform

This patch add scanning of ebc bus to of_platform, which is needed
to recognize devices located on that bus.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>

Index: linux-2.6.19-rc6/arch/powerpc/kernel/of_platform.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- linux-2.6.19-rc6.orig/arch/powerpc/kernel/of_platform.c
+++ linux-2.6.19-rc6/arch/powerpc/kernel/of_platform.c
@@ -50,6 +50,7 @@ static struct of_device_id of_default_bu
 	{ .type =3D "plb5", },
 	{ .type =3D "plb4", },
 	{ .type =3D "opb", },
+	{ .type =3D "ebc", },
 	{},
 };
=20


--=20
Mit freundlichen Gr=FCssen,
kind regards,

Christian Krafft
IBM Systems & Technology Group,=20
Linux Kernel Development
IT Specialist

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Benjamin Herrenschmidt]

On Fri, 2006-12-08 at 11:41 +0100, Christian Krafft wrote:
> Subject: powerpc: add scanning of ebc bus to of_platform
> 
> This patch add scanning of ebc bus to of_platform, which is needed
> to recognize devices located on that bus.
> 
> Signed-off-by: Christian Krafft <krafft@de.ibm.com>

I'd like other people opinions here... But I'm tempted to remove the
"default" list of bus types here and have it always be passed by the
platform... just in case.

If you guys prefer to keep it that way, then fine, patch is

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Ben.

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Segher Boessenkool]

> I'd like other people opinions here... But I'm tempted to remove the
> "default" list of bus types here and have it always be passed by the
> platform... just in case.

That's probably best -- no sense in registering devices
on buses that the platform doesn't know how to drive!


Segher

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Arnd Bergmann]

On Saturday 09 December 2006 11:04, Segher Boessenkool wrote:
> 
> > I'd like other people opinions here... But I'm tempted to remove the
> > "default" list of bus types here and have it always be passed by the
> > platform... just in case.

I think for the flat device tree, we often have only type=soc,
or compatible=soc anyway, and there is a limited number of
internal bus types we want to probe on top of that for real
OF implementations.

> That's probably best -- no sense in registering devices
> on buses that the platform doesn't know how to drive!

But the platform doesn't need how to drive them, the device driver
needs to. All the platform needs to know is the fact that it can
deal with SOC devices that are automatically probed.

I'd much prefer to have the list in the same file that drives the
devices in the first place. It's probably also good to register
them as MODULE_DEVICE_TABLE(), for documentation purposes, even
if the driver can't be built as a module yet.

	Arnd <><

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Segher Boessenkool]

>> That's probably best -- no sense in registering devices
>> on buses that the platform doesn't know how to drive!
>
> But the platform doesn't need how to drive them, the device driver
> needs to.

No -- the platform needs to know how to do low-level
bus operations (I/O reads, etc).  For most memory-mapped
buses this is pretty trivial, of course.

Maybe we're just disagreeing over the word "platform"
here?


Segher

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Paul Mackerras]

Arnd Bergmann writes:

> But the platform doesn't need how to drive them, the device driver
> needs to. All the platform needs to know is the fact that it can
> deal with SOC devices that are automatically probed.
> 
> I'd much prefer to have the list in the same file that drives the
> devices in the first place. It's probably also good to register
> them as MODULE_DEVICE_TABLE(), for documentation purposes, even
> if the driver can't be built as a module yet.

So is that an ack or a nack for the patch?  Sounds like a nack to me,
but I'm not sure. :)

Paul.

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Benjamin Herrenschmidt]

On Mon, 2006-12-11 at 13:25 +1100, Paul Mackerras wrote:
> Arnd Bergmann writes:
> 
> > But the platform doesn't need how to drive them, the device driver
> > needs to. All the platform needs to know is the fact that it can
> > deal with SOC devices that are automatically probed.
> > 
> > I'd much prefer to have the list in the same file that drives the
> > devices in the first place. It's probably also good to register
> > them as MODULE_DEVICE_TABLE(), for documentation purposes, even
> > if the driver can't be built as a module yet.
> 
> So is that an ack or a nack for the patch?  Sounds like a nack to me,
> but I'm not sure. :)

Put it in for now.

Ben.

Re: [patch] powerpc: add scanning of ebc bus to of_platform

[Arnd Bergmann]

On Monday 11 December 2006 07:56, Benjamin Herrenschmidt wrote:
>=20
> > an ack or a nack for the patch? =A0Sounds like a nack to me,
> > but I'm not sure. :)
>=20
> Put it in for now.
>=20

Yes, definitely. I was not objecting to Christian's patch anyway,
but to Ben's idea of getting rid of that part of the code, which
is a side-discussion.

	Arnd <><