Why Are Vega 64 Fans Idle With Some 4.18+ Kernels But Not Others?

Operating Systems & Open Source Linux
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The fans on the AMD Vega 64 card in this machine should be idle below 60C.

They are idle with a shipping 4.18-or-above Fedora or Ubuntu kernel.

They are not idle with a 4.18-or-above mainline kernel from Canonical’s kernel PPA.

Results are mixed with a 4.18-or-above kernel on other distributions.

My memory says this AMD Vega idle fan business was introduced in 4.18. But, I can’t find anything that verifies that.

So… is this a compile-time option? Can I set a boot parameter to trigger this behavior?

1 Like
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From what I’m reading you are saying that fan behavior for the Vega 64 card varies between the 4.18 kernel versions across distributions.

Fedora and Ubuntu are checking out ok, as the fans Idle.

It may be that other distributions don’t have the code checked in or added yet for whatever reason. Each distro has its own code base and reviewers… not sure how that all works with drivers for cards and stuff.

Was there a particular issue you are trying to solve?

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I don’t want the Vega 64 fans to spin below 60C, as designed.

I recall that code enabling this was introduced in the 4.18 series. Obviously, some 4.18+ kernels packaged by distributions do not enable it. For those kernels, I’d like to know if there is anything I, as a user, can do to enable the feature, short of building my own kernel.

This feature kicks in early in the boot process and, at least on my hardware, the silencing of the fans is very obvious and welcome. I won’t use distributions that do not enable it.

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If you have the AMDGPU driver installed, the open source one, you can edit the fan speed directly without dependency of the kernel.

cat /sys/class/drm/card0/device/hwmon/hwmon1/pwm1

will show how fast the fans are going. to edit you can

echo "[speed]" > /sys/class/drm/card0/device/hwmon/hwmon1/pwm1

(obviously the amdgpu driver depends on a kernel version 4.XX not sure tbh)

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Right. I don’t game so the fan’s default behavior – idle below 60C – is what I want. I don’t really need to manually set fan speeds, or even read them.

I’m looking for the specific difference between 4.18+ kernels that enable this and 4.18+ kernels that don’t and hoping there’s some boot-time kernel option that does enable it on the latter.

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I’m interested in your findings.

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If that is your prime concern, use the distributions that implements it correctly

If the distribution you want to use does not implement it correctly and you cannot mitigate the problem, maybe try an Arch kernel or Clear Linux/Solus?

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You’ve misunderstood my question.

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You want other to do the work you don’t want to do for you.

You got several people commenting on your question and even giving you tips on how to fix it.

Then tell: What EXACTLY is your question? Try to state it as precise and specific as possible.

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I quoted what i thought you were seeking as a solution

I do not intend to stand under any of the other questions about kernels because it appears to be the actions of what is known on Linux forums as a ‘help vampire’

best of luck resolving your problem

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in my first post:

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I’m interested in your findings.

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use radeon-profile GUI to get consistent fan control.