While assigning the sequence number to subsystem instances by reading the
aliases property, only DT nodes names are compared and not the complete
path. This causes a problem when there are two DT nodes with same name but
have different paths.
In arch/arm/dts/k3-am65-main.dtsi there are two USB controllers with the
same device tree node name but different path. When aliases are defined for
these USB controllers then fdtdec_get_alias_seq() fails to pick the correct
instance for a given index.
fdt_path_offset() function is slow and this would effect the uboot startup.
To avert the time penalty on all boards, apply this extra check only when
required by using a config option.
Fix it by comparing the phandles of DT nodes after the node names match,
under a config option.
Signed-off-by: Aswath Govindraju <a-govindr...@ti.com>
---
Changes since v1:
- Added a config option as fdt_path_offset() slows down the u-boot start
up and would be better to be enabled only when required
- Added an example case in commit message where the following fix is
required.
lib/Kconfig | 8 ++++++++
lib/fdtdec.c | 11 +++++++++++
2 files changed, 19 insertions(+)
diff --git a/lib/Kconfig b/lib/Kconfig
index 8efb154f7344..9813a3a5e0ba 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -685,3 +685,11 @@ config LIB_ELF
This supports fir 32 bit and 64 bit versions.
endmenu
+
+config PHANDLE_CHECK_SEQ
+ bool "Enable phandle check while getting sequence number"
+ default n
+ help
+ When there are multiple device tree nodes with same name,
+ enable this config option to distinguish them using
+ phandles in fdtdec_get_alias_seq() function.
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index ee1bd41b0818..60aa1bd8cf1b 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -500,6 +500,17 @@ int fdtdec_get_alias_seq(const void *blob, const char
*base, int offset,
slash = strrchr(prop, '/');
if (strcmp(slash + 1, find_name))
continue;
+
+ /*
+ * Adding an extra check to distinguish DT nodes with
+ * same name
+ */
+ #ifdef CONFIG_PHANDLE_CHECK_SEQ
+ if (fdt_get_phandle(blob, offset) !=
+ fdt_get_phandle(blob, fdt_path_offset(blob, prop)))
+ continue;
+ #endif
+
val = trailing_strtol(name);
if (val != -1) {
*seqp = val;
--
2.17.1
