Re: [PATCH 2/2] dtc: libfdt: Introduce a can_assume check in fdt_check_full

[Rasmus Villemoes <rv@rasmusvillemoes.dk>]

On Tue, May 26 2026, Tom Rini <trini@konsulko.com> wrote:

> The current upstream method of having a function omit various tests is
> to use the can_assume macro. Take the logic we had previously been using
> and instead make it a can_assume(PERFECT) check within fdt_check_full
> itself.
>
> Signed-off-by: Tom Rini <trini@konsulko.com>
> ---
> I will be submitting this change upstream and will follow up if needed
> here.
> ---
>  scripts/dtc/libfdt/fdt_check.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/scripts/dtc/libfdt/fdt_check.c b/scripts/dtc/libfdt/fdt_check.c
> index a21ebbc9239f..7509c11d8580 100644
> --- a/scripts/dtc/libfdt/fdt_check.c
> +++ b/scripts/dtc/libfdt/fdt_check.c
> @@ -21,6 +21,8 @@ int fdt_check_full(const void *fdt, size_t bufsize)
>  	const char *propname;
>  	bool expect_end = false;
>  
> +	if (can_assume(PERFECT))
> +		return 0;

Is this right? I think that would require changing can_assume() to test
if the given mask is a subset of FDT_ASSUME_MASK, not merely intersects
it. When called with a single-bit mask, those are of course the same
thing.

Because as-is, can_assume(PERFECT) is true if FDT_ASSUME_MASK has any
non-zero value, but I don't think FDT_ASSUME_MASK=ASSUME_LATEST, for
example, should imply "perfect".

Rasmus