[freber]

What

The 15-inch M3 MacBook Air (J615) has no entry in the macsmc-hwmon board table, so it never gets a macsmc_soc_die thermal zone. Without that zone the M3 GPU thermal limit has nothing to read. This line is logged every 30 seconds after boot.

asahi 292400000.gpu: M3: thermal: no SoC die temperature (no SoC die temperature zone), runtime cap 2 (618 MHz) of 2..=2

The J615 uses the same T8122 as the J613, which got its keys in 8fd1bf4. This PR gives the J615 the same twelve die keys. I left out pressure_key because I haven't checked that the J615's SMC has mTPL.

Testing

• MacBook Air (15-inch, M3, 2024), apple,j615 / apple,t8122, 10 active GPU cores
• linux-aurora 7.2.11.aurora16-1, m1n1-aurora 1.6.1.aurora23-2, mesa-aurora 26.3.0_devel.20261107, Hyprland 0.57.2
• OS firmware 14.7, system firmware 26.6.2

I tested the keys without rebuilding the kernel, by reloading the packaged module with them as a parameter.

modprobe macsmc_hwmon soc_die_keys=Tg0D,Tg0P,Tg0X,Tg0b,Tg0j,Tg0v,Te05,Te0P,Tp05,Tp0L,Tp0b,Tp0r

macsmc-hwmon macsmc-hwmon: SoC die temperature zone macsmc_soc_die: hottest of Tg0D Tg0P Tg0X Tg0b Tg0j Tg0v Te05 Te0P Tp05 Tp0L Tp0b Tp0r (12 of 12 listed keys present)
asahi 292400000.gpu: M3: thermal: SoC die temperature 67.3 C from zones: macsmc_soc_die (SMC die sensors)

After that I put the same option in /etc/modprobe.d and booted with asahi.t8122_pstate_cap=5. The zone comes up at boot and reads 58 to 70 C at idle and with light desktop use. The governor uses it (runtime cap 5 (1056 MHz), firmware peak state 5).

Not tested:

• A kernel built from this branch. I only loaded the packaged module with the parameter.
• How each Tg key responds under GPU-only load on the J615. I had no GPU benchmark on the machine, so the key choice rests on the J613 measurements in 8fd1bf4.
• mTPL on the J615.

#164 notes that the J615 isn't qualified for states 6 to 8. This zone is the first thing that work needs. I'll add a comment on that issue.

🤖 Generated with Claude Code