2011-02-02 18:59:54

by H. Peter Anvin

[permalink] [raw]
Subject: Re: [sodaville] [PATCH v2 01/15] x86/e820: remove conditional early mapping in parse_e820_ext

On 01/27/2011 11:54 AM, Daniel Drake wrote:
>
> This patch will indeed cause problems for OLPC. Thanks for bringing it
> to our attention.
>
> On OLPC, the device tree is not used as a source of devices like on
> other platforms, it is simply used to present information to the
> kernel and userspace (in read-only fashion).
>
> If I understand it correctly, the above patch is saying: if we have a
> device tree, don't add the standard x86 RTC device.
>
> However, what we need it to say is: if we have a device tree *and* the
> device tree is being used as a source of devices, don't add the
> standard x86 RTC device.
>
> Therefore in the OLPC case, this particular bail-out condition will
> never be met, because the device tree is not being used as a source of
> devices.
>
> Does that make sense?
>

It makes sense in the abstract, but it sounds like OLPC is a total WTF
in this sense...

-hpa