Hi Simon, On 03/12/20 3:51 am, Simon Glass wrote: > Hi Aswath, > > On Wed, 2 Dec 2020 at 08:42, Aswath Govindraju <a-govindr...@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 uboot startup. > > U-Boot >
Corrected this. >> 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 (IS_ENABLED(CONFIG... > Corrected this. > (did you not get a warning from patman on that?) No, I am not getting it. Thank you for the comments. I made the changes that you suggested and I posted a respin. Thanks, Aswath > >> + 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 >> > > Regards, > SImon >