# How to load a module which is in old kernel version

## pd1986

Hello, due to the fan control, I would like to load a fan control module which is in the kernel 3.8 which control perfectly my laptop fan when I compiled new kernel. How could I do this? Please show me the full details. Thanks in advance.

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## szatox

You can try to `modprobe --force <modulename>' (refer to man modprobe),, but you would do much better if you recompiled your current kernel to have this module avialible in new version.

You know, it is supposed to work this way. Using the dark side of --force is considered dangerous, so while I give you an answer to question you asked, I also say you asked wrong question.

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## pd1986

 *szatox wrote:*   

> You can try to `modprobe --force <modulename>' (refer to man modprobe),, but you would do much better if you recompiled your current kernel to have this module avialible in new version.
> 
> You know, it is supposed to work this way. Using the dark side of --force is considered dangerous, so while I give you an answer to question you asked, I also say you asked wrong question.

 

What I mean is that the fan control module in the new kernel 3.15 (for example) doesn't work well in my laptop. However, the fan module in kernel 3.8 works perfectly. So, I want to use kernel 3.15 but with fan module from kernel 3.8.

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## Hu

We understood that from your first message.  The point from szatox stands though: kernel modules are tightly integrated with the kernel ABI.  There is no guarantee that the v3.8 fan module will load correctly on v3.15 even with --force nor any guarantee that, if it loads, it will not have unwanted side effects.  You should report the problem upstream so that the kernel developers can produce a v3.15 module that works correctly for you.

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## pd1986

 *Hu wrote:*   

> We understood that from your first message.  The point from szatox stands though: kernel modules are tightly integrated with the kernel ABI.  There is no guarantee that the v3.8 fan module will load correctly on v3.15 even with --force nor any guarantee that, if it loads, it will not have unwanted side effects.  You should report the problem upstream so that the kernel developers can produce a v3.15 module that works correctly for you.

 

Thanks, I found an option which support the module loading in different kernel which is called CONFIG_MODVERSIONS in "gentoo-sources" but I just don't know how it works. Does it mean that I only need recompile the fan as module in the kernel 3.8 and modprobe in kernel 3.15?

I have reported many times but this fan problem has been troubling me several years and never been revolved completely. My Toshiba (Portege M901) laptop is so strange. That's why I am always using kernel 3.8 as it works perfectly with my fan control.

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## cwr

Errr, dumb question, but if kernel 3.8 works and 3.15 doesn't, why are you upgrading?

You can update most of the rest of the the system without ever touching the kernel.

Will

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## eccerr0r

I'd highly recommend against using 3.8.x kernels, they have nasty bugs in them.

I still wonder why there's regression.  Where did you report it? It might be something that should go straight to the LKML as suggested.

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## dachschaden

Dude ...

Why don't you vimdiff both kernel sources for your fan control module, and look for something that could make your 3.15 kernel run incorrectly? This is going to be MUCH safer than trying to load a module compiled for a kernel deprecated some time ago.

If you can't read code, then at least tell the kernel team about the problem, and don't try to screw things up.

The best thing that can happen will that everything works like expected - but don't rely on that.

The most probable thing to happen (and the best, since it indicates that the kernel is self-aware enough to shut itself down rather than allowing to damage your hardware) is a kernel panic.

And the worst thing will cause permanent damage to your hardware.

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## pd1986

 *cwr wrote:*   

> Errr, dumb question, but if kernel 3.8 works and 3.15 doesn't, why are you upgrading?
> 
> You can update most of the rest of the the system without ever touching the kernel.
> 
> Will

 

Beeeeecauuuuuuse.....

 *eccerr0r wrote:*   

> I'd highly recommend against using 3.8.x kernels, they have nasty bugs in them.
> 
> I still wonder why there's regression.  Where did you report it? It might be something that should go straight to the LKML as suggested.

 

and 3.8.x have been removed from the portage tree.

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## pd1986

 *eccerr0r wrote:*   

> I'd highly recommend against using 3.8.x kernels, they have nasty bugs in them.
> 
> I still wonder why there's regression.  Where did you report it? It might be something that should go straight to the LKML as suggested.

 

I reported here. https://bugzilla.kernel.org/

I don't know what they have done. I have to admit that my fan control in Toshiba Portege M901 is really so strange. I have tried all the methods that I could find from Google, none of it works. Finally, I found one way to start the fan manually (thanks to the report in bugzilla). then it worked perfectly in my laptop. However, from 3.9.X, this kind to control failed. They upgraded it and the fan could start automatically while the fan could only works at maximum speed......

I am pretty sure that I will change my laptop in the following months, so I don't want to spend so much time in it.

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## pd1986

 *dachschaden wrote:*   

> Dude ...
> 
> Why don't you vimdiff both kernel sources for your fan control module, and look for something that could make your 3.15 kernel run incorrectly? This is going to be MUCH safer than trying to load a module compiled for a kernel deprecated some time ago.
> 
> If you can't read code, then at least tell the kernel team about the problem, and don't try to screw things up.
> ...

 

Thank you. Sorry, I can't read the code. I won't spend much time on it as I will change laptop in the following months. I am just wondering if it is possible to do what I said. If it is not recommended, I will stop thinking of that.

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