FS#4097 - "Fails": setting TxPower to 0,1,2 dBm with mt76 on GL-MT300N-V2 (SoC MT7628N)

[openwrt-bot]

ghmon:

I own a power density meter (and now how to use it) and checked how 0..20 dBm setting and applying with LuCi affects power density.

Surprising not expected result: 0,1,2 dBm result in slightly higher power densities than 20 dBm. As expected: 3 dBm is a very lowe value, increasing with higher settings up to 20 dBm.

So either the driver or the hardware does not support that values, for whatever reason; might be a bug. I found nothing in the mt7628n data sheet for this issue.

Suggestion - LuCi should not allow to set these values, or mt76 (if it's not a bug in mt76) should set 3 dBm for 0,1,2 dBm.

[openwrt-bot]

ghmon:

Additional observation - on a "FRITZ!Box 7360 V2" with lscpu reported "MIPS 34Kc V5.6" (above system has "MIPS 24KEc V5.5"), OpenWrt 21.02.0-rc4.

Setting txpower here to LuCi with 0,1,2 dBm is also accepted. After setting and "Save and apply" LuCi reports 3 dBm is really set. Might be some relation to the case described above.