Re: [PATCH] RFC: platform/x86: wmi: Fix check for method instance number

From: Andy Shevchenko
Date: Sun Aug 06 2017 - 12:10:55 EST


On Sun, Aug 6, 2017 at 6:35 PM, Pali RohÃr <pali.rohar@xxxxxxxxx> wrote:
> On Wednesday 05 July 2017 22:24:20 Pali RohÃr wrote:
>> On Wednesday 05 July 2017 21:30:35 David Airlie wrote:

>> > > On Saturday 17 June 2017 18:47:54 Pali RohÃr wrote:
>> > > > > So problematic drivers which use instance=1 without any
>> > > > > comments
>> > > > > are:
>> > > > > acer-wmi
>> > > > > asus-wmi
>> > > > > mxm-wmi


> Hi! For mxm-wmi I found this document:
> https://lekensteyn.nl/files/docs/mxm-2.1-software-spec.pdf
>
> On page numbered 26 (resp. in PDF page 31) is information about WMI
> GUID {F6CB5C3C-9CAE-4EBD-B577-931EA32A2CC0} interface and there is
> written that instance count = 1.
>
> // Methods GUID {F6CB5C3C-9CAE-4ebd-B577-931EA32A2CC0}
> 0x3C, 0x5C, 0xCB, 0xF6, 0xAE, 0x9C, 0xbd, 0x4e, 0xB5, 0x77, 0x93,
> 0x1E, 0xA3, 0x2A, 0x2C, 0xC0,
> 0x4D, 0x58, // Object ID âMXâ = method âWMMXâ
> 1, // Instance Count
> 0x02, // Flags (WMIACPI_REGFLAG_METHOD)
>
> And ACPI method for handling this WMI call does not check Arg0 and Arg1
> at all.
>
> So... Andy, Darren, any objections for following patch which changes
> instance number from one to zero?

No objections from me! Just put enough explanation into commit message.

--
With Best Regards,
Andy Shevchenko