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authorRob Herring <robh@kernel.org>2017-10-03 11:07:55 -0500
committerRob Herring <robh@kernel.org>2017-10-16 13:43:29 -0500
commit77ea8a68c54ede3fd60dadb6a49b597f6eb5aee7 (patch)
tree38a0e128b10134641f114f87dac9ed6d88ec4d3d
parentecc8a96e251dc43d13841bac44fbfa34ec20fc52 (diff)
downloadlinux-next-77ea8a68c54ede3fd60dadb6a49b597f6eb5aee7.tar.gz
of/fdt: skip unflattening of disabled nodes
For static DT usecases, we don't need the disabled nodes and can skip unflattening. This saves a significant amount of RAM in memory constrained cases. In one example on STM32F469, the RAM usage goes from 118K to 26K. There are a few cases in the kernel that modify the status property dynamically. These all are changes from enabled to disabled, depend on OF_DYNAMIC or are not FDT based (PDT based). Tested-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Rob Herring <robh@kernel.org>
-rw-r--r--drivers/of/fdt.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index f8c39705418b..2d515b85a198 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -396,6 +396,10 @@ static int unflatten_dt_nodes(const void *blob,
if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
continue;
+ if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
+ !of_fdt_device_is_available(blob, offset))
+ continue;
+
if (!populate_node(blob, offset, &mem, nps[depth],
&nps[depth+1], dryrun))
return mem - base;