Fix OF_finddevice error return value in case of FDT.

According to the open firmware standard, finddevice call has to return
a phandle with value of -1 in case of error.

This commit is to:
- Fix the FDT implementation of this interface (ofw_fdt_finddevice) to
  return (phandle_t)-1 in case of error, instead of 0 as it does now.
- Fix up the callers of OF_finddevice() to compare the return value with
  -1 instead of 0 to check for errors.
- Since phandle_t is unsigned, the return value of OF_finddevice should
  be checked with '== -1' rather than '<= 0' or '> 0', fix up these cases
  as well.

Reported by:	nwhitehorn

Reviewed by:	raj
Approved by:	raj, nwhitehorn

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/dev/fdt/fdt_powerpc.c b/sys/dev/fdt/fdt_powerpc.c
index ea614db..ac81c08 100644
--- a/sys/dev/fdt/fdt_powerpc.c
+++ b/sys/dev/fdt/fdt_powerpc.c
@@ -62,7 +62,7 @@ fdt_fixup_busfreq(phandle_t root)
 	 * This fixup uses /cpus/ bus-frequency prop value to set simple-bus
 	 * bus-frequency property.
 	 */
-	if ((cpus = OF_finddevice("/cpus")) == 0)
+	if ((cpus = OF_finddevice("/cpus")) == -1)
 		return;
 
 	if ((child = OF_child(cpus)) == 0)