From 8c237cd0ccb570d13158758af02e11359a4a5b1c Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 9 Jun 2016 15:50:49 +1000 Subject: drivers/of: Fix depth for sub-tree blob in unflatten_dt_nodes() The function is unflattening device sub-tree blob if @dad passed to the function is valid. Currently, this functionality is used by PPC PowerNV PCI hotplug driver only. There are possibly multiple nodes in the first level of depth, fdt_next_node() bails immediately when @depth becomes negative before the second device node can be probed successfully. It leads to the device nodes except the first one won't be unflattened successfully. This fixes the issue by setting the initial depth (@inital_depth) to 1 when this function is called to unflatten device sub-tree blob. No logic changes when this function is used to unflatten non-sub-tree blob. Cc: Rhyland Klein Fixes: 78c44d910 ("drivers/of: Fix depth when unflattening devicetree") Signed-off-by: Gavin Shan Tested-by: Rhyland Klein Tested-by: Andrew Donnellan Signed-off-by: Rob Herring --- drivers/of/fdt.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 14f2f8c7c260..33daffc4392c 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -395,7 +395,7 @@ static int unflatten_dt_nodes(const void *blob, struct device_node **nodepp) { struct device_node *root; - int offset = 0, depth = 0; + int offset = 0, depth = 0, initial_depth = 0; #define FDT_MAX_DEPTH 64 unsigned int fpsizes[FDT_MAX_DEPTH]; struct device_node *nps[FDT_MAX_DEPTH]; @@ -405,11 +405,22 @@ static int unflatten_dt_nodes(const void *blob, if (nodepp) *nodepp = NULL; + /* + * We're unflattening device sub-tree if @dad is valid. There are + * possibly multiple nodes in the first level of depth. We need + * set @depth to 1 to make fdt_next_node() happy as it bails + * immediately when negative @depth is found. Otherwise, the device + * nodes except the first one won't be unflattened successfully. + */ + if (dad) + depth = initial_depth = 1; + root = dad; fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0; nps[depth] = dad; + for (offset = 0; - offset >= 0 && depth >= 0; + offset >= 0 && depth >= initial_depth; offset = fdt_next_node(blob, offset, &depth)) { if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH)) continue; -- cgit v1.2.3-58-ga151