[PATCH] powerpc: #address-cells & #size-cells properties not inherited

[PATCH] powerpc: #address-cells & #size-cells properties not inherited

[Mark A. Greer]

From: Mark A. Greer <mgreer@mvista.com>

Fix error in booting-without-of.txt that indicates that a node can inherit
its #address-cells and #size-cells definitions from its parent's parent.
This is not correct and the latest dtc enforces it.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
---
 Documentation/powerpc/booting-without-of.txt |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index ee0209a..58db5ea 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -671,10 +671,10 @@ device or bus to be described by the device tree.
 
 In general, the format of an address for a device is defined by the
 parent bus type, based on the #address-cells and #size-cells
-property. In the absence of such a property, the parent's parent
-values are used, etc... The kernel requires the root node to have
-those properties defining addresses format for devices directly mapped
-on the processor bus.
+properties.  Note that the parent's parent definitions of #address-cells
+and #size-cells are not inhereted so every node with children must specify
+them.  The kernel requires the root node to have those properties defining
+addresses format for devices directly mapped on the processor bus.
 
 Those 2 properties define 'cells' for representing an address and a
 size. A "cell" is a 32-bit number. For example, if both contain 2

Re: [PATCH] powerpc: #address-cells & #size-cells properties not inherited

[Josh Boyer]

On Wed, 2 Jan 2008 17:07:50 -0700
"Mark A. Greer" <mgreer@mvista.com> wrote:

> From: Mark A. Greer <mgreer@mvista.com>
> 
> Fix error in booting-without-of.txt that indicates that a node can inherit
> its #address-cells and #size-cells definitions from its parent's parent.
> This is not correct and the latest dtc enforces it.

I'm lazy so I haven't checked myself, but by "latest dtc" does that
mean the DTC that's in the kernel now?

Things are going to be fun when we start saying generic things like
"latest DTC".  And when upstream DTC gets new features or enforcements,
we'll have to have all the in-kernel DTS files patched up when that
version of DTC gets merged in-kernel.  Just something to keep in mind
as we move along.

josh

Re: [PATCH] powerpc: #address-cells & #size-cells properties not inherited

[David Gibson]

On Wed, Jan 02, 2008 at 05:07:50PM -0700, Mark A. Greer wrote:
> From: Mark A. Greer <mgreer@mvista.com>
> 
> Fix error in booting-without-of.txt that indicates that a node can inherit
> its #address-cells and #size-cells definitions from its parent's parent.
> This is not correct and the latest dtc enforces it.

For small values of "enforce"; it's a warning only.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [PATCH] powerpc: #address-cells & #size-cells properties not inherited

[Mark A. Greer]

On Wed, Jan 02, 2008 at 07:46:40PM -0600, Josh Boyer wrote:
> On Wed, 2 Jan 2008 17:07:50 -0700
> "Mark A. Greer" <mgreer@mvista.com> wrote:
> 
> > From: Mark A. Greer <mgreer@mvista.com>
> > 
> > Fix error in booting-without-of.txt that indicates that a node can inherit
> > its #address-cells and #size-cells definitions from its parent's parent.
> > This is not correct and the latest dtc enforces it.
> 
> I'm lazy so I haven't checked myself, but by "latest dtc" does that
> mean the DTC that's in the kernel now?
> 
> Things are going to be fun when we start saying generic things like
> "latest DTC".  And when upstream DTC gets new features or enforcements,
> we'll have to have all the in-kernel DTS files patched up when that
> version of DTC gets merged in-kernel.  Just something to keep in mind
> as we move along.

Yeah, I thought about that last night, actually.
I think I'll just change that sentence to "This is not correct."

Avoid the issue :)

Mark

[PATCH v2] powerpc: #address-cells & #size-cells properties not inherited

[Mark A. Greer]

From: Mark A. Greer <mgreer@mvista.com>

Fix error in booting-without-of.txt that indicates that a node can inherit
its #address-cells and #size-cells definitions from its parent's parent.
This is not correct.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
---
 Documentation/powerpc/booting-without-of.txt |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index ee0209a..58db5ea 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -671,10 +671,10 @@ device or bus to be described by the device tree.
 
 In general, the format of an address for a device is defined by the
 parent bus type, based on the #address-cells and #size-cells
-property. In the absence of such a property, the parent's parent
-values are used, etc... The kernel requires the root node to have
-those properties defining addresses format for devices directly mapped
-on the processor bus.
+properties.  Note that the parent's parent definitions of #address-cells
+and #size-cells are not inhereted so every node with children must specify
+them.  The kernel requires the root node to have those properties defining
+addresses format for devices directly mapped on the processor bus.
 
 Those 2 properties define 'cells' for representing an address and a
 size. A "cell" is a 32-bit number. For example, if both contain 2

Re: [PATCH] powerpc: #address-cells & #size-cells properties not inherited

[Josh Boyer]

On Thu, 3 Jan 2008 08:32:56 -0700
"Mark A. Greer" <mgreer@mvista.com> wrote:

> On Wed, Jan 02, 2008 at 07:46:40PM -0600, Josh Boyer wrote:
> > On Wed, 2 Jan 2008 17:07:50 -0700
> > "Mark A. Greer" <mgreer@mvista.com> wrote:
> > 
> > > From: Mark A. Greer <mgreer@mvista.com>
> > > 
> > > Fix error in booting-without-of.txt that indicates that a node can inherit
> > > its #address-cells and #size-cells definitions from its parent's parent.
> > > This is not correct and the latest dtc enforces it.
> > 
> > I'm lazy so I haven't checked myself, but by "latest dtc" does that
> > mean the DTC that's in the kernel now?
> > 
> > Things are going to be fun when we start saying generic things like
> > "latest DTC".  And when upstream DTC gets new features or enforcements,
> > we'll have to have all the in-kernel DTS files patched up when that
> > version of DTC gets merged in-kernel.  Just something to keep in mind
> > as we move along.
> 
> Yeah, I thought about that last night, actually.
> I think I'll just change that sentence to "This is not correct."
> 
> Avoid the issue :)

Lazy!  I like it ;)

josh