RE: [PATCH v2] platform/x86: wmi-bmof: New driver to expose embedded Binary WMI MOF metadata

From: Mario.Limonciello
Date: Mon Jun 19 2017 - 12:13:57 EST


> -----Original Message-----
> From: Pali RohÃr [mailto:pali.rohar@xxxxxxxxx]
> Sent: Monday, June 19, 2017 11:08 AM
> To: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: platform-driver-x86@xxxxxxxxxxxxxxx; Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx>; Andy Lutomirski <luto@xxxxxxxxxxxxxx>;
> Limonciello, Mario <Mario_Limonciello@xxxxxxxx>; Rafael Wysocki
> <rjw@xxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2] platform/x86: wmi-bmof: New driver to expose embedded
> Binary WMI MOF metadata
>
> On Tuesday 06 June 2017 05:16:44 Andy Lutomirski wrote:
> > Many laptops (and maybe servers?) have embedded WMI Binary MOF
> > metadata. We do not yet have open-source tools for processing the
> > data, although one is in the works thanks to Pali:
> >
> > https://github.com/pali/bmfdec
> >
> > There is currently no interface to get the data in the first place.
> > By exposing it, we facilitate the development of new tools.
> >
> > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> > Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> > Cc: Mario Limonciello <mario_limonciello@xxxxxxxx>
> > Cc: Pali RohÃr <pali.rohar@xxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: platform-driver-x86@xxxxxxxxxxxxxxx
> > Cc: linux-acpi@xxxxxxxxxxxxxxx
> > [dvhart: make sysfs mof binary read only, fixup comment block format]
> > [dvhart: use bmof terminology and dev_err instead of dev_warn]
> > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > Signed-off-by: Darren Hart (VMware) <dvhart@xxxxxxxxxxxxx>
> > ---
> > since-v1:
> > * address Pali's comments:
> > * update the cover letter for clarity and accuracy
> > * update mof->bmof and MOF to Binary MOF throughout the patch
> > * use dev_err instead of dev_warn in wmi_bmof_probe
> >
> >
> > drivers/platform/x86/Kconfig | 12 ++++
> > drivers/platform/x86/Makefile | 1 +
> > drivers/platform/x86/wmi-bmof.c | 125
>
> Another suggestion (unrelated to this patch): For working with ACPI-WMI,
> this binary MOF buffer is not enough. It is needed also content of _WDG
> buffer. What about exporting it too via sysfs? Probably not part of of
> wmi-bmof driver, but wmi driver itself.
>

I think this depends upon how the userspace access to WMI methods gets
implemented, no? If userpsace access to WMI methods show up as
/dev/wmi-$GUID-$INSTANCE and those internally to the kernel map to
the proper ASL methods for example, what you get from wmi-bmof
should be enough shouldn't it?