After looking thru the ACPI tables of various people having issues
with the bitland-mifs-wmi driver, i came to the following conclusions:

1. There seem to be multiple flavors of the Mifs interface,
distinguishable by small changes inside their WMI MOF definitions

2. The buffer format used to communicate with the ACPI-WMI firmware
operates differently than previously thought.

This patch series addresses the second point I am aware that there
exist multiple outstanding patch series that partially overlap with
this one. All of those patch series still rely on the incorrect buffer
format currently being used by the driver, so i suggest that this
patch series be used as a new base for future patches.

All patches have been tested by a user on his Redmi Book Pro 16 2024.

Armin Wolf (2):
  platform/x86: bitland-mifs-wmi: Detect failed function calls
  platform/x86: bitland-mifs-wmi: Treat WMI_FN_SYSTEM_AC_TYPE as
    optional

 .../wmi/devices/bitland-mifs-wmi.rst          |  64 +++++---
 drivers/platform/x86/bitland-mifs-wmi.c       | 146 +++++++++---------
 2 files changed, 117 insertions(+), 93 deletions(-)

-- 
2.39.5

On Sat, 05 Sep 2026 00:45:14 +0200, Armin Wolf wrote:

> After looking thru the ACPI tables of various people having issues
> with the bitland-mifs-wmi driver, i came to the following conclusions:
> 
> 1. There seem to be multiple flavors of the Mifs interface,
> distinguishable by small changes inside their WMI MOF definitions
> 
> 2. The buffer format used to communicate with the ACPI-WMI firmware
> operates differently than previously thought.
> 
> [...]

Thank you for your contribution, it has been applied to my local
review-ilpo-next branch. Note it will show up in the public
platform-drivers-x86/review-ilpo-next branch only once I've pushed my
local branch there, which might take a while.

FYI [if applicable to your patch], as per Linus' policy change, also
fixes are mostly routed through for-next unless the fix is for a
commit introduced in the most recent cycle or is clearly a regression
fix.

The list of commits applied:
[1/2] platform/x86: bitland-mifs-wmi: Detect failed function calls
      commit: 437954f921dc60a5a988f0a6b343e9e5734b872a
[2/2] platform/x86: bitland-mifs-wmi: Treat WMI_FN_SYSTEM_AC_TYPE as optional
      commit: 46482926cce834fa6cb3b08246f10455a0694b03

--
 i.

Am 15.09.26 um 13:32 schrieb Ilpo Järvinen:

> On Sat, 05 Sep 2026 00:45:14 +0200, Armin Wolf wrote:
>
>> After looking thru the ACPI tables of various people having issues
>> with the bitland-mifs-wmi driver, i came to the following conclusions:
>>
>> 1. There seem to be multiple flavors of the Mifs interface,
>> distinguishable by small changes inside their WMI MOF definitions
>>
>> 2. The buffer format used to communicate with the ACPI-WMI firmware
>> operates differently than previously thought.
>>
>> [...]
> Thank you for your contribution, it has been applied to my local
> review-ilpo-next branch. Note it will show up in the public
> platform-drivers-x86/review-ilpo-next branch only once I've pushed my
> local branch there, which might take a while.

Thank you :)

Armin Wolf

> FYI [if applicable to your patch], as per Linus' policy change, also
> fixes are mostly routed through for-next unless the fix is for a
> commit introduced in the most recent cycle or is clearly a regression
> fix.
>
> The list of commits applied:
> [1/2] platform/x86: bitland-mifs-wmi: Detect failed function calls
>        commit: 437954f921dc60a5a988f0a6b343e9e5734b872a
> [2/2] platform/x86: bitland-mifs-wmi: Treat WMI_FN_SYSTEM_AC_TYPE as optional
>        commit: 46482926cce834fa6cb3b08246f10455a0694b03
>
> --
>   i.
>
>