Merge pull request RIOT-OS#20446 from benpicco/net/gnrc/routing/ipv6_…

…auto_subnets-docfix

gnrc/ipv6_auto_subnets: clarify documentation

sys/net/gnrc/routing/ipv6_auto_subnets/gnrc_ipv6_auto_subnets.c

@@ -133,7 +133,7 @@
  * @brief How many bits of a new prefix have to match the old prefix
  * for it to be considered for replacement.
  *
- * Set this if you want to join multiple subnets at the same time.
+ * Set this if you want to join multiple upstream subnets at the same time.
  *
  * If you use `gnrc_ipv6_auto_subnets` instead of `gnrc_ipv6_auto_subnets_simple`
  * make sure to also set CONFIG_GNRC_IPV6_AUTO_SUBNETS_NUMOF accordingly.
@@ -153,7 +153,8 @@
 /**
  * @brief Number of subnets that can be configured.
  *
- * This is not needed when using the `gnrc_ipv6_auto_subnets_simple` module.
+ * This is not needed when using the `gnrc_ipv6_auto_subnets_simple` module
+ * or if only a single upstream subnet is to be partitioned.
  *
  * If this is set to any number higher than 1, make sure to also configure
  * CONFIG_GNRC_IPV6_AUTO_SUBNETS_PREFIX_FIX_LEN to suit your setup.
@@ -166,9 +167,9 @@
  * @brief Enable this if you have a static network that might experience
  * high packet loss under certain conditions.
  * If enabled, this option causes the module to always assume the highest
- * number of subnets it has ever seen.
- * This prevents different/conflicting subnets from being configured if
- * multiple sync packets got lost.
+ * number of downstream routers it has ever seen.
+ * This prevents different/conflicting downstream subnets from being configured
+ * if multiple sync packets got lost.
  */
 #ifndef CONFIG_GNRC_IPV6_AUTO_SUBNETS_STATIC
 #define CONFIG_GNRC_IPV6_AUTO_SUBNETS_STATIC (0)