Which -mtune (for GL AR150)?

I am just having look at LEDE (GitHub - lede-project/source: Mirror of https://git.lede-project.org/?p=source.git Please send your PRs against this tree. They will be merged via staging trees and appear in this tree once the staging trees get merged back into source.git) and found out that they’ve provided different -mtune flags for the AR150…

openwrt/.config:CONFIG_TARGET_OPTIMIZATION=“-Os -pipe -mno-branch-likely -mips32r2 -mtune=34kc”
lede-project/.config:CONFIG_TARGET_OPTIMIZATION=“-Os -pipe -mno-branch-likely -mips32r2 -mtune=24kc”

Which is better? I have been running OpenWRT/DD with -mtune=24kc no issues so far.

I couldn’t find how those flags are (auto)configured, any pointers?

I don’t know this. Can you ask in LEDE and find out, also let us know?