On Thu, Jun 12, 2025 at 05:13:34PM +0000, James Morse wrote:
> acpi_count_levels() passes the number of levels back via a pointer argument.
> It also passes this to acpi_find_cache_level() as the starting_level, and
> preserves this value as it walks up the cpu_node tree counting the levels.
>
> The only caller acpi_get_cache_info() happens to have already initialised
> levels to zero, which acpi_count_levels() depends on to get the correct
> result.
>
> Explicitly zero the levels variable, so the count always starts at zero.
> This saves any additional callers having to work out they need to do this.
>
> Signed-off-by: James Morse <james.morse@xxxxxxx>
> ---
> drivers/acpi/pptt.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
> index aaf9b5a26d07..72e6bfc1e358 100644
> --- a/drivers/acpi/pptt.c
> +++ b/drivers/acpi/pptt.c
> @@ -183,7 +183,7 @@ acpi_find_cache_level(struct acpi_table_header *table_hdr,
> * @cpu_node: processor node we wish to count caches for
> * @levels: Number of levels if success.
> * @split_levels: Number of split cache levels (data/instruction) if
> - * success. Can by NULL.
> + * success. Can be NULL.
> *
> * Given a processor node containing a processing unit, walk into it and count
> * how many levels exist solely for it, and then walk up each level until we hit
> @@ -196,6 +196,8 @@ static void acpi_count_levels(struct acpi_table_header *table_hdr,
> struct acpi_pptt_processor *cpu_node,
> unsigned int *levels, unsigned int *split_levels)
> {
> + *levels = 0;
> +
Does it make sense to drop similar reset to 0 in acpi_get_cache_info(), just
to be consistent across all callers of acpi_count_levels().
Otherwise, LGTM:
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
--
Regards,
Sudeep
