Re: [PATCH v14 RESEND 0/6] Merge redmi-wmi into bitland-mifs-wmi

[Chris Taraszka]

On Mon, 26 Oct 2026, Hans de Goede wrote:
> 1) This assumes the event indicates a platform-profile-change has happened, if
> it is a request for a platform-profile-change then platform_profile_cycle();
> should be used instead.

Hi,

Some data for this and for Mingyou's KBD_BRIGHTNESS question, from the
Xiaomi Book Pro 14 (TM2424, BIOS XMAPT4B0P0A0A), traced with a kprobe
on bitland_mifs_wmi_notify() with v13 on v7.3 (v14 has the same event
handling):

- Fn+Space (keyboard backlight) sends no WMI event at all, neither 0x05
  nor anything else, and does not change the backlight under Linux. So
  this model cannot tell whether the firmware handles KBD_BRIGHTNESS.

- Fn+K sends event 0x28 with value_low 0x01 on every press (01 28 01 00),
  not 0x16. The firmware does not change the mode by itself: the
  SystemPerMode value (EC 0x68) stays the same across the presses. If
  0x28 is the performance mode key on this model, it is a request rather
  than a notification, so platform_profile_cycle() would fit. 0x28 is
  currently logged as "Unknown WMI event".

- On Windows on the same machine, with Xiaomi PC Manager not running
  (it fails to start on this install), neither Fn+K nor Fn+Space does
  anything either. So Fn+K looks like a request that Xiaomi's software
  normally acts on, not a mode change made by the firmware.

- Mic mute sends 0x21 with value_low 1 and 0 and is reported as
  KEY_MICMUTE, as expected.

Thanks,
Chris