Re: Missing ACPI driver for a keyboard button in Xiaomi RedmiBook Pro 16

[Armin Wolf <W_Armin@gmx.de>]

Am 20.07.25 um 01:39 schrieb Nikita Krasnov:

> Hello!
>
> I have a Xiaomi RedmiBook Pro 16 laptop and I suspect it is missing a
> driver.
>
> The laptop has a top row of F1-F12 buttons that can also control volume,
> brightness and many other things. Most of them work fine and produce a
> completely valid output (shown via `acpi_listen` from the `acpid`
> package):
>
>    button/mute MUTE 00000080 00000000
>    button/volumedown VOLDN 00000080 00000000
>    button/volumeup VOLUP 00000080 00000000
>    video/brightnessdown BRTDN 00000087 00000000
>    video/brightnessup BRTUP 00000086 00000000
>
> But then there is a "Mute mic" key (F4 button with an image of a
> crossed-out microphone). It has an LED that lights up and down when the
> button is being pressed, but there is no keycode, no dmesg message and
> no _valid_ ACPI event — the message in `acpi_listen` is always the same,
> no matter the state of the button. Pressing the button multiple times
> produces the same output:
>
>    wmi PNP0C14:00 00000020 00000000
>
> Might be a good time to mention that I nave 0 experience with ACPI, WMI
> and drivers in general... I tried debugging the issue further and got
> some data, but I lack the proper knowledge to interpret it.
>
> Running `acpidump -b` (from `acpica-tools` package) generated some .dat
> files which I then decompiled with `iasl -d` (from the same
> `acpica-tools` package).
>
>    # acpidump -b
>    # iasl -d dsdt.dat
>
> The resulting `dsdt.dsl` file has some code that mentions "PNP0C14".
> I've attached this file with this email.

Hi,

please share the whole output of acpidump as the DSDT contains only two unrelated
WMI devices.

> I also tried restarting the kernel with this configuration (NixOS
> shenanigans; not sure what exactly it does there), but that didn't seem
> to produce any extra files or directories on the system (in /sys and
> /dev).
>
>    boot.initrd.availableKernelModules = [
>      "xhci_pci"
>      "thunderbolt"
>      "nvme"
>      "usb_storage"
>      "sd_mod"
>    ];
>    boot.initrd.kernelModules = [ ];
>    boot.kernelModules = [ "kvm-intel" "wmi-sysfs" "wmi" "acpi_call" ];
>    boot.extraModulePackages = [ ];

Those additional modules will likely not help you, i suspect that we need
to extend the xiaomi-wmi driver a bit to add support for additional keyboard
events.

> Here is some extra info that might be relevant:
>
>    $ ls /dev/wmi
>    ls: cannot access '/dev/wmi': No such file or directory
>
>    $ ls -1 /sys/bus/wmi/devices
>    05901221-D566-11D1-B2F0-00A0C9062910
>    05901221-D566-11D1-B2F0-00A0C9062910-1
>    05901221-D566-11D1-B2F0-00A0C9062910-2
>    05901221-D566-11D1-B2F0-00A0C9062910-3
>    1DCEAF0A-4D63-44BB-BD0C-0D6281BFDDC5
>    1F13AB7F-6220-4210-8F8E-8BB5E71EE969
>    2BC49DEF-7B15-4F05-8BB7-EE37B9547C0B
>    3F9E3C26-B077-4F86-91F5-37FF64D8C7ED
>    46C93E13-EE9B-4262-8488-563BCA757FEF
>    657B6048-310C-4A90-A211-10A17922A0AF
>    A6FEA33E-DABF-46F5-BFC8-460D961BEC9F
>    B60BFB48-3E5B-49E4-A0E9-8CFFE1B3434B
>    F80A5498-23F3-4053-A244-B39067EC476F
>    FA78E245-2C0F-4CA1-91CF-15F34E474850
>
>    $ ls /sys/bus/wmi/devices/2BC49DEF-7B15-4F05-8BB7-EE37B9547C0B/
>    driver_override  expensive  guid  instance_count
>    modalias  object_id  power  subsystem  uevent
>
>    $ uname -a
>    Linux 6.15.5 #1-NixOS SMP PREEMPT_DYNAMIC x86_64 GNU/Linux
>    
>    $ ls /proc/acpi
>    button  wakeup
>
>    $ sudo cat /proc/acpi/button/lid/LID0/state
>    state:      open
>
>    $ sudo cat /proc/acpi/wakeup
>    Device    S-state    Status     Sysfs node
>    AWAC      S4         *enabled   platform:ACPI000E:00
>    XDCI      S4         *disabled
>    XHCI      S4         *enabled   pci:0000:00:14.0
>    HDAS      S4         *disabled  pci:0000:00:1f.3
>    I3C0      S4         *disabled
>    CNVW      S4         *disabled  pci:0000:00:14.3
>    RP01      S4         *disabled
>    PXSX      S4         *disabled
>    RP02      S4         *disabled
>    PXSX      S4         *disabled
>    RP03      S4         *disabled
>    PXSX      S4         *disabled
>    RP04      S4         *disabled
>    PXSX      S4         *disabled
>    RP05      S4         *disabled
>    PXSX      S4         *disabled
>    RP06      S4         *disabled
>    PXSX      S4         *disabled
>    RP07      S4         *disabled
>    PXSX      S4         *disabled
>    RP08      S4         *disabled
>    PXSX      S4         *disabled
>    RP09      S4         *enabled   pci:0000:00:06.0
>    PXSX      S4         *disabled  pci:0000:01:00.0
>    RP10      S4         *disabled
>    PXSX      S4         *disabled
>    RP11      S4         *disabled
>    PXSX      S4         *disabled
>    RP12      S4         *disabled
>    PXSX      S4         *disabled
>    TXHC      S4         *enabled   pci:0000:00:0d.0
>    TDM0      S4         *enabled   pci:0000:00:0d.2
>    TDM1      S4         *disabled
>    TRP0      S4         *disabled
>    PXSX      S4         *disabled
>    TRP1      S4         *enabled   pci:0000:00:07.0
>    PXSX      S4         *disabled
>    TRP2      S4         *disabled
>    PXSX      S4         *disabled
>    TRP3      S4         *disabled
>    PXSX      S4         *disabled
>
> As I said, I don't actually understand what I'm doing here, but I'd
> really like to learn! It would be really cool if I ended up having to
> write and contribute my first driver!
>
> Sorry if I am somehow posting this incorrectly. This is my first time
> communicating here, just trying my best.

You already provided a lot of data, good job :).

I think that we do not need another driver in this case, as the xiaomi-wmi driver
is responsible for handling WMI events on Xiaomi devices. I can check what needs
to be done in order to add support for those additional keyboard events, but for
that i need the full output of acpidump.

Thanks,
Armin Wolf

>
> P.S. CC'ing W_Armin@gmx.de, linux@weissschuh.net and fengwk94@gmail.com
> since I've got the impression you have some experience with this.
>