Re: [PATCH v10] HID: steelseries: Add MSI Raider A18 HX A9WJG RGB support

[Jiri Kosina]

On Fri, 5 Jun 2026, David Glushkov wrote:

> The MSI Raider A18 HX A9WJG exposes two internal SteelSeries USB HID
> devices for RGB lighting: KLC (1038:1122) for the keyboard and ALC
> (1038:1161) for the lightbar/logo zones.
> 
> Add DMI-gated support for these devices and expose them as multicolor
> LED class devices. The driver sends the same HID class SET_REPORT
> control transfer as the tested userspace implementation for this
> machine and writes a uniform RGB value to all known keyboard keys or
> ALC zones.
> 
> The ALC payload uses sparse LED IDs on this chassis: 0x00, 0x01,
> 0x02 and 0x03 are physical zones, while 0x04 and 0x05 do not appear
> to map to physical LEDs. Unused payload LED ID slots are initialized
> to 0xff so they are ignored by the controller instead of defaulting
> to LED ID 0x00.
> 
> Limit RGB support to USB interface 0 and the tested DMI system because
> the KLC product ID is shared across MSI laptop designs and the key
> layout mapping is model-specific. If the DMI or interface check does
> not match, keep the device bound as a regular HID device instead of
> failing probe.
> 
> Also make the existing Arctis 9 vendor usage-page check defensive by
> returning false for report descriptors shorter than three bytes before
> inspecting hdev->rdesc[0..2].
> 
> Tested on MSI Raider A18 HX A9WJG. Both internal SteelSeries ALC
> (1038:1161) and KLC (1038:1122) HID devices bind on interface 0 and
> create steelseries::lightbar and steelseries::kbd_backlight. Setting
> multi_intensity and brightness changes the keyboard and lightbar
> colors.
> 
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202606010709.X0QYNjFZ-lkp@xxxxxxxxx/
> Signed-off-by: David Glushkov <david.glushkov@xxxxxxxxx>

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs