Re: [PATCH] samsung-laptop: Disable if CONFIG_EFI=y

From: Matt Fleming
Date: Sun Nov 04 2012 - 15:58:51 EST


On Sun, 2012-11-04 at 09:47 -0800, Jonathan Nieder wrote:
> Matt Fleming wrote:
>
> > --- a/drivers/platform/x86/Kconfig
> > +++ b/drivers/platform/x86/Kconfig
> > @@ -717,7 +717,7 @@ config XO15_EBOOK
> >
> > config SAMSUNG_LAPTOP
> > tristate "Samsung Laptop driver"
> > - depends on X86
> > + depends on X86 && !EFI
>
> That means distros would just not get the samsung-laptop driver.
> Is there a runtime check that could be used instead?

Well, the closest thing we have at the moment is the 'efi_enabled'
variable, but that doesn't actually mean "We were booted from EFI?", it
means "Do we have EFI runtime services?", and that's not a broad enough
check for this case. We don't have access to the EFI runtime services
when a 64-bit kernel is booted from 32-bit EFI firmware or vice-versa.
Notably the chromebooks use this scheme. And seeing as Samsung make
chromebooks, I'm not convinced we won't hit that case.

But yeah, you've got a valid point. Clearly we need a way to check this
at runtime. I'll repsin this patch.

--
Matt Fleming, Intel Open Source Technology Center

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