Re: Correct use of __init and __devinit

[Sam Ravnborg]

On Sun, Dec 23, 2007 at 04:56:14PM +0000, Adrian McMenamin wrote:
> Could someone here help settle this argument?
> 
> I have written a driver (for the CD Rom on the Sega Dreamcast). I have
> marked various initialisation functions - including probe() and the
> functions that it, and only it, calls, as __init.
> 
> Other developers tell me I should mark them as __devinit.
> 
> However I think this is wrong as:
> 
> * The CD on the Dreamcast is not and will never be a hotpluggable device
> 
> * The Dreamcast is a limited memory device and if marking various
> functions as __init helps save memory that is A Good Thing
> 
> It has been put to me that while the use case (not hotpluggable) is
> correct, it is still better practice to use __devinit
If you use the register* functions of the driver model then
you are no longer in 100% control when your functions are
called.
So of the principle of least suprise it is best to use __devinit
for the probe function as most other drivers do. And if
the driver model happens to call your probe function after
init time then we will not oops.

So wit other words - use same pattern a other drivers and accept
that we could have saved a few hundred bytes extra but we do not do so.

	Sam
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/