[PATCH 2/2] wrapper: Treat NULL as root node in devp_offset; add devp_offset_find().

[PATCH 2/2] wrapper: Treat NULL as root node in devp_offset; add devp_offset_find().

[Scott Wood]

Many operations, as currently used in the wrapper, assume they can
pass NULL and have it be treated as the root node.  However, libfdt-wrapper
converts NULL to -1, which is only appropriate when searching for nodes,
and will cause an error otherwise.

Signed-off-by: Scott Wood <scottwood@freescale.com>
---
 arch/powerpc/boot/libfdt-wrapper.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/boot/libfdt-wrapper.c b/arch/powerpc/boot/libfdt-wrapper.c
index 868c504..97af36c 100644
--- a/arch/powerpc/boot/libfdt-wrapper.c
+++ b/arch/powerpc/boot/libfdt-wrapper.c
@@ -48,7 +48,8 @@
 		check_err(_offset) ? NULL : (void *)(_offset+1); \
 	})
 
-#define devp_offset(devp)	(((int)(devp))-1)
+#define devp_offset_find(devp)	(((int)(devp))-1)
+#define devp_offset(devp)	(devp ? ((int)(devp))-1 : 0)
 
 static void *fdt;
 static void *buf; /* = NULL */
@@ -127,8 +128,9 @@ static void *fdt_wrapper_find_node_by_prop_value(const void *prev,
 						 const char *val,
 						 int len)
 {
-	return offset_devp(fdt_node_offset_by_prop_value(fdt, devp_offset(prev),
-							 name, val, len));
+	int offset = fdt_node_offset_by_prop_value(fdt, devp_offset_find(prev),
+	                                           name, val, len);
+	return offset_devp(offset);
 }
 
 static char *fdt_wrapper_get_path(const void *devp, char *buf, int len)
-- 
1.5.3.7

Re: [PATCH 2/2] wrapper: Treat NULL as root node in devp_offset; add devp_offset_find().

[David Gibson]

On Tue, Dec 11, 2007 at 03:23:05PM -0600, Scott Wood wrote:
> Many operations, as currently used in the wrapper, assume they can
> pass NULL and have it be treated as the root node.  However, libfdt-wrapper
> converts NULL to -1, which is only appropriate when searching for nodes,
> and will cause an error otherwise.

Hrm.  AFAICT "many" in this case, means three (being calls to
create_node() in devtree.c, main.c and planetcore.c).

Still I guess this patch is ok for now.  I futgure I'd like to shrink
the wrapper down and make the general interface be as close as
possible to the native libfdt interface.

> Signed-off-by: Scott Wood <scottwood@freescale.com>

Acked-by: David Gibson <david@gibson.dropbear.id.au>

-- 
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