SK-AM62A-LP: PMIC Thermal shutdown overrides VTM thermal shutdown limit?

Shreyash Yadav

Prodigy 30 points

Part Number: SK-AM62A-LP

Tool/software:

HW- SK-AM62A-LP

SW: 11.01.07.05\

As mentioned in the post AM625: Linux thermal management question

I tried to disable the thermal management on the board for debug purpose as mentioned in the above post by modifying the thermal.dtsi file to temp = 190C and type=hot.
I have rebuild the kernel and verified that my new build has the appropriate changes where they should be.

But still the board undergoes thermal shutdown as soon as it reaches 121-122C ,the SoC temperature measured via the /sys/class/thermal.....

Is it that the PMIC is triggering a hardware based thermal shutdown? Is there any way to determine this or modify this?

Thanks and regards,

2 days ago

0 Anshu Madwesh 1 day ago

TI__Genius 17950 points

Hello,

The Linux VTM driver defines thermal shutdown at 123C as defined by the MAX_TEMP global variable.

https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/thermal/k3_j72xx_bandgap.c?h=ti-linux-6.12.y#n45

https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/thermal/k3_j72xx_bandgap.c?h=ti-linux-6.12.y#n363

When you reach this thermal shutdown, what does dmesg last print?

Thanks,

Anshu

0 Shreyash Yadav 1 day ago in reply to Anshu Madwesh

Prodigy 30 points

After modifying the DTSI file, there is nothing printed on the dmesg print and the processor just power cycles. I guess that is because the file you mentioned configures the VTM registers which sends interrupt below the linux level.

Also the file you mentioned is based on J72xx family SoCs. Can you tell me where is the MAX_TEMP global variable defined for the AM62A in the SDK?

0 Anshu Madwesh 15 hours ago in reply to Shreyash Yadav

TI__Genius 17950 points

Hello,

If nothing was printed, then it was likely caused at the hardware level.

AM62A uses the same driver: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm64/boot/dts/ti/k3-am62a-wakeup.dtsi?h=ti-linux-6.12.y#n145

https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/thermal/k3_j72xx_bandgap.c?h=ti-linux-6.12.y#n582

Thanks,

Anshu

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SK-AM62A-LP: PMIC Thermal shutdown overrides VTM thermal shutdown limit?