| Message ID | 20201203052545.2387-1-a-govindraju@ti.com |
|---|---|
| State | Accepted |
| Delegated to: | Simon Glass |
| Headers | show |
| Series | [v3] fdt: Use phandle to distinguish DT nodes with same name | expand |
On Wed, 2 Dec 2020 at 22:26, Aswath Govindraju <a-govindraju@ti.com> wrote: > > 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 U-Boot > 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-govindraju@ti.com> > --- > > Changes since v2: > - changed #ifdef to if(IS_ENABLED()) > - corrected errors in commit description > > 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(+) > Reviewed-by: Simon Glass <sjg@chromium.org>
On Wed, 2 Dec 2020 at 22:26, Aswath Govindraju <a-govindraju@ti.com> wrote: > > 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 U-Boot > 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-govindraju@ti.com> > --- > > Changes since v2: > - changed #ifdef to if(IS_ENABLED()) > - corrected errors in commit description > > 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(+) > Reviewed-by: Simon Glass <sjg@chromium.org> Applied to u-boot-dm/next, thanks!
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..0ab7105fef0d 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 + */ + if (IS_ENABLED(CONFIG_PHANDLE_CHECK_SEQ)) { + if (fdt_get_phandle(blob, offset) != + fdt_get_phandle(blob, fdt_path_offset(blob, prop))) + continue; + } + val = trailing_strtol(name); if (val != -1) { *seqp = val;
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 U-Boot 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-govindraju@ti.com> --- Changes since v2: - changed #ifdef to if(IS_ENABLED()) - corrected errors in commit description 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(+)