[PATCH 1/2] powerpc: export ppc_tb_freq so that modules can reference it

Josh Boyer jwboyer at gmail.com
Sun Sep 19 02:56:44 EST 2010

On Sat, Sep 18, 2010 at 11:34 AM, Kumar Gala <kumar.gala at freescale.com> wrote:
> On Sep 18, 2010, at 9:36 AM, Tabi Timur-B04825 wrote:
>> On Sep 17, 2010, at 10:14 PM, "Benjamin Herrenschmidt" <benh at kernel.crashing.org> wrote:
>>> On Fri, 2010-09-17 at 20:20 -0500, Timur Tabi wrote:
>>>> I don't see any reason to limit it to GPL drivers.  Not only that, but
>>>> then we'll have this:
>>> I do
>> Can you elaborate on that, or are you just going to pull rank on me?
>>>> EXPORT_SYMBOL(ppc_proc_freq);
>>>> EXPORT_SYMBOL_GPL(ppc_tb_freq);
>>>> That just looks dumb.
>>> Right, so send a patch to fix the first one too :-)
> I don't think either of these should be EXPORT_SYMBOL_GPL.  Why shouldn't a binary module be allowed to know these frequencies?  My view is why preclude anyone from using this how they want.  If they want to live in the gray area so be it.  Who am I to say they shouldn't have that choice.

It is not, in my opinion, about what is technically possible and what
isn't.  The kernel is licensed under the GPL.  This is a Linux kernel
only symbol.  One would be hard pressed to claim they have a driver
that wasn't written for Linux that happens to need that symbol.  As a
member of the Linux kernel community, I find it important to encourage
the contribution of code back to the kernel, and this is one way to
help that.  This isn't BSD.

Besides, a developer is free to export it however they wish in their
own kernel tree.  They can deviate from mainline if they so choose.


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