[PATCH 2/5] Devicetree/PPC: fix devicetree's fixup

[Juergen Borleis]

Currently Barebox fails to boot a kernel/devicetree pair on PowerPC.

With of_find_node_by_path() the framework uses a global variable to find
the root node and fails. With of_find_node_by_path_from() and forwarding
the 'root' parameter it works again as expected.

This fixes the following error message at run-time:

Loading U-Boot uImage '/tmp/tftpcmd/kernel'
Loading devicetree from '/tmp/tftpcmd/oftree'
bootm: No devicetree given.
handler failed with: Invalid argument

Signed-off-by: Juergen Borleis <jbe at pengutronix.de>
---
 arch/ppc/mach-mpc5xxx/cpu.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/ppc/mach-mpc5xxx/cpu.c b/arch/ppc/mach-mpc5xxx/cpu.c
index c860e70..a53af63 100644
--- a/arch/ppc/mach-mpc5xxx/cpu.c
+++ b/arch/ppc/mach-mpc5xxx/cpu.c
@@ -83,17 +83,21 @@ static int of_mpc5200_fixup(struct device_node *root, void *unused)
 
 	int div = in_8((void*)CFG_MBAR + 0x204) & 0x0020 ? 8 : 4;
 
-	node = of_find_node_by_path("/cpus/PowerPC,5200 at 0");
-	if (!node)
+	node = of_find_node_by_path_from(root, "/cpus/PowerPC,5200 at 0");
+	if (!node) {
+		pr_err("Cannot find node '/cpus/PowerPC,5200 at 0' for proper CPU frequency fixup\n");
 		return -EINVAL;
+	}
 
 	of_property_write_u32(node, "timebase-frequency", get_timebase_clock());
 	of_property_write_u32(node, "bus-frequency", get_bus_clock());
 	of_property_write_u32(node, "clock-frequency", get_cpu_clock());
 
-	node = of_find_node_by_path("/soc5200 at f0000000");
-	if (!node)
+	node = of_find_node_by_path_from(root, "/soc5200 at f0000000");
+	if (!node) {
+		pr_err("Cannot find node '/soc5200 at f0000000' for proper SOC frequency fixup\n");
 		return -EINVAL;
+	}
 
 	of_property_write_u32(node, "bus-frequency", get_ipb_clock());
 	of_property_write_u32(node, "system-frequency", get_bus_clock() * div);
-- 
2.1.4