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

From: Greg KH
Date: Mon Nov 05 2012 - 05:39:44 EST


On Sun, Nov 04, 2012 at 05:35:06PM +0000, Matt Fleming wrote:
> From: Matt Fleming <matt.fleming@xxxxxxxxx>
>
> We've started getting reports of users seeing Machine Check Exceptions
> when booting their Samsung laptops in UEFI mode,
>
> https://bugzilla.kernel.org/show_bug.cgi?id=47121
>
> This module seems to be the culprit as it's grovelling around in the
> 0xf0000 region which has no mapping in either the e820 or EFI memory
> maps on the affected machines.

So, does this mean that if we try to ioremap a memory location in the
kernel, like this driver is, it will not fail, but, when accessing the
memory, bad things happen?

That's not good, shouldn't the call to ioremap_nocache() have failed
originally? That sounds like a core EFI/platform bug here, and one that
you might run into other places.

Shouldn't fixing that be the real fix?


thanks,

greg k-h
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