HID: usbhid: Insert USB bus/device ID into HID name #7061

6by9 · 2025-09-22T15:47:17Z

libinput/wlroots/Wayfire/labwc match input device by the device name only. If you add 2 identical USB connected touch devices, you can't select between them.

Add the usb bus&device name to the start of the name so that the names end up being unique,

Supercedes #6356
Addresses raspberrypi/bookworm-feedback#446
https://forums.raspberrypi.com/viewtopic.php?t=376569

P33M · 2025-09-22T15:57:43Z

Nit: trailing comma in the commit message. Otherwise, lgtm.

libinput/wlroots/Wayfire/labwc match input device by the device name only. If you add 2 identical USB connected touch devices, you can't select between them. Add the usb bus&device name to the start of the name so that the names end up being unique. Signed-off-by: Dave Stevenson <[email protected]>

6by9 · 2025-09-22T16:04:42Z

Nit: trailing comma in the commit message. Otherwise, lgtm.

Fixed.

HiassofT · 2025-09-22T18:15:57Z

Please don't fiddle around with the name, this breaks name-based udev/hwdb matches and likely other programs, too.

Connect eg a Logitech M100 mouse and observe that the MOUSE_DPI= setting will be missing in udevadm info output, because the hwdb entry https://github.com/systemd/systemd/blob/v258/hwdb.d/70-mouse.hwdb#L694-L696 no longer matches.

udevadm info output with plain 6.12.48 RPi kernel:

P: /devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001/input/input2/event2
M: event2
R: 2
J: c13:66
U: input
D: c 13:66
N: input/event2
L: 0
S: input/by-path/platform-xhci-hcd.1-usb-0:1:1.0-event-mouse
S: input/by-path/platform-xhci-hcd.1-usbv2-0:1:1.0-event-mouse
S: input/by-id/usb-Logitech_USB_Optical_Mouse-event-mouse
E: DEVPATH=/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001/input/input2/event2
E: DEVNAME=/dev/input/event2
E: MAJOR=13
E: MINOR=66
E: SUBSYSTEM=input
E: USEC_INITIALIZED=11747040
E: ID_INPUT=1
E: ID_INPUT_MOUSE=1
E: ID_BUS=usb
E: ID_MODEL=USB_Optical_Mouse
E: ID_MODEL_ENC=USB\x20Optical\x20Mouse
E: ID_MODEL_ID=c05a
E: ID_SERIAL=Logitech_USB_Optical_Mouse
E: ID_VENDOR=Logitech
E: ID_VENDOR_ENC=Logitech
E: ID_VENDOR_ID=046d
E: ID_REVISION=6300
E: ID_TYPE=hid
E: ID_USB_MODEL=USB_Optical_Mouse
E: ID_USB_MODEL_ENC=USB\x20Optical\x20Mouse
E: ID_USB_MODEL_ID=c05a
E: ID_USB_SERIAL=Logitech_USB_Optical_Mouse
E: ID_USB_VENDOR=Logitech
E: ID_USB_VENDOR_ENC=Logitech
E: ID_USB_VENDOR_ID=046d
E: ID_USB_REVISION=6300
E: ID_USB_TYPE=hid
E: ID_USB_INTERFACES=:030102:
E: ID_USB_INTERFACE_NUM=00
E: ID_USB_DRIVER=usbhid
E: ID_PATH_WITH_USB_REVISION=platform-xhci-hcd.1-usbv2-0:1:1.0
E: ID_PATH=platform-xhci-hcd.1-usb-0:1:1.0
E: ID_PATH_TAG=platform-xhci-hcd_1-usb-0_1_1_0
E: KEY=70000 0 0 0 0
E: MOUSE_DPI=1000@125
E: LIBINPUT_DEVICE_GROUP=3/46d/c05a:usb-xhci-hcd.1-1
E: DEVLINKS=/dev/input/by-path/platform-xhci-hcd.1-usb-0:1:1.0-event-mouse /dev/input/by-path/platform-xhci-hcd.1-usbv2-0:1:1.0-event-mouse /dev/input/by-id/usb-Logitech_USB_Optical_Mouse-event-mouse

udevadm info output with this PR:

P: /devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001/input/input2/event2
M: event2
R: 2
J: c13:66
U: input
D: c 13:66
N: input/event2
L: 0
S: input/by-id/usb-Logitech_USB_Optical_Mouse-event-mouse
S: input/by-path/platform-xhci-hcd.1-usb-0:1:1.0-event-mouse
S: input/by-path/platform-xhci-hcd.1-usbv2-0:1:1.0-event-mouse
E: DEVPATH=/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001/input/input2/event2
E: DEVNAME=/dev/input/event2
E: MAJOR=13
E: MINOR=66
E: SUBSYSTEM=input
E: USEC_INITIALIZED=9187506
E: ID_INPUT=1
E: ID_INPUT_MOUSE=1
E: ID_BUS=usb
E: ID_MODEL=USB_Optical_Mouse
E: ID_MODEL_ENC=USB\x20Optical\x20Mouse
E: ID_MODEL_ID=c05a
E: ID_SERIAL=Logitech_USB_Optical_Mouse
E: ID_VENDOR=Logitech
E: ID_VENDOR_ENC=Logitech
E: ID_VENDOR_ID=046d
E: ID_REVISION=6300
E: ID_TYPE=hid
E: ID_USB_MODEL=USB_Optical_Mouse
E: ID_USB_MODEL_ENC=USB\x20Optical\x20Mouse
E: ID_USB_MODEL_ID=c05a
E: ID_USB_SERIAL=Logitech_USB_Optical_Mouse
E: ID_USB_VENDOR=Logitech
E: ID_USB_VENDOR_ENC=Logitech
E: ID_USB_VENDOR_ID=046d
E: ID_USB_REVISION=6300
E: ID_USB_TYPE=hid
E: ID_USB_INTERFACES=:030102:
E: ID_USB_INTERFACE_NUM=00
E: ID_USB_DRIVER=usbhid
E: ID_PATH_WITH_USB_REVISION=platform-xhci-hcd.1-usbv2-0:1:1.0
E: ID_PATH=platform-xhci-hcd.1-usb-0:1:1.0
E: ID_PATH_TAG=platform-xhci-hcd_1-usb-0_1_1_0
E: KEY=70000 0 0 0 0
E: LIBINPUT_DEVICE_GROUP=3/46d/c05a:usb-xhci-hcd.1-1
E: DEVLINKS=/dev/input/by-id/usb-Logitech_USB_Optical_Mouse-event-mouse /dev/input/by-path/platform-xhci-hcd.1-usb-0:1:1.0-event-mouse /dev/input/by-path/platform-xhci-hcd.1-usbv2-0:1:1.0-event-mouse

If you have issues with labwc please fix it there.

pelwell · 2025-09-22T20:01:20Z

If you have issues with labwc please fix it there.

Are you saying that, with the unmodified kernel, labwc already has enough information to be able to distinguish between multiple instances of identical USB devices?

HiassofT · 2025-09-22T20:28:43Z

I'm not familiar with labwc but all the needed seems to be available from udev.

Looking at udevadm info -a the info from the added usb-x-y string in the name is available as KERNEL(S) info 3 parent nodes up:

  looking at device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001/input/input2/event2':
    KERNEL=="event2"
    SUBSYSTEM=="input"
    DRIVER==""
    ATTR{power/control}=="auto"
    ATTR{power/runtime_active_time}=="0"
    ATTR{power/runtime_status}=="unsupported"
    ATTR{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001/input/input2':
    KERNELS=="input2"
    SUBSYSTEMS=="input"
    DRIVERS==""
    ATTRS{capabilities/abs}=="0"
    ATTRS{capabilities/ev}=="17"
    ATTRS{capabilities/ff}=="0"
    ATTRS{capabilities/key}=="70000 0 0 0 0"
    ATTRS{capabilities/led}=="0"
    ATTRS{capabilities/msc}=="10"
    ATTRS{capabilities/rel}=="903"
    ATTRS{capabilities/snd}=="0"
    ATTRS{capabilities/sw}=="0"
    ATTRS{id/bustype}=="0003"
    ATTRS{id/product}=="c05a"
    ATTRS{id/vendor}=="046d"
    ATTRS{id/version}=="0111"
    ATTRS{inhibited}=="0"
    ATTRS{name}=="usb-3-1 Logitech USB Optical Mouse"
    ATTRS{phys}=="usb-xhci-hcd.1-1/input0"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{properties}=="0"
    ATTRS{uniq}==""

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0/0003:046D:C05A.0001':
    KERNELS=="0003:046D:C05A.0001"
    SUBSYSTEMS=="hid"
    DRIVERS=="hid-generic"
    ATTRS{country}=="00"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1/3-1:1.0':
    KERNELS=="3-1:1.0"
    SUBSYSTEMS=="usb"
    DRIVERS=="usbhid"
    ATTRS{authorized}=="1"
    ATTRS{bAlternateSetting}==" 0"
    ATTRS{bInterfaceClass}=="03"
    ATTRS{bInterfaceNumber}=="00"
    ATTRS{bInterfaceProtocol}=="02"
    ATTRS{bInterfaceSubClass}=="01"
    ATTRS{bNumEndpoints}=="01"
    ATTRS{supports_autosuspend}=="1"

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3/3-1':
    KERNELS=="3-1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{authorized}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bDeviceClass}=="00"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bMaxPacketSize0}=="8"
    ATTRS{bMaxPower}=="100mA"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bcdDevice}=="6300"
    ATTRS{bmAttributes}=="a0"
    ATTRS{busnum}=="3"
    ATTRS{configuration}==""
    ATTRS{devnum}=="2"
    ATTRS{devpath}=="1"
    ATTRS{devspec}=="(null)"
    ATTRS{idProduct}=="c05a"
    ATTRS{idVendor}=="046d"
    ATTRS{ltm_capable}=="no"
    ATTRS{manufacturer}=="Logitech"
    ATTRS{maxchild}=="0"
    ATTRS{power/active_duration}=="39310"
    ATTRS{power/autosuspend}=="2"
    ATTRS{power/autosuspend_delay_ms}=="2000"
    ATTRS{power/connected_duration}=="39310"
    ATTRS{power/control}=="on"
    ATTRS{power/level}=="on"
    ATTRS{power/persist}=="1"
    ATTRS{power/runtime_active_time}=="39050"
    ATTRS{power/runtime_status}=="active"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{product}=="USB Optical Mouse"
    ATTRS{quirks}=="0x0"
    ATTRS{removable}=="unknown"
    ATTRS{remove}=="(not readable)"
    ATTRS{rx_lanes}=="1"
    ATTRS{speed}=="1.5"
    ATTRS{tx_lanes}=="1"
    ATTRS{urbnum}=="11"
    ATTRS{version}==" 2.00"

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1/usb3':
    KERNELS=="usb3"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{authorized}=="1"
    ATTRS{authorized_default}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bDeviceClass}=="09"
    ATTRS{bDeviceProtocol}=="01"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{bMaxPower}=="0mA"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bcdDevice}=="0612"
    ATTRS{bmAttributes}=="e0"
    ATTRS{busnum}=="3"
    ATTRS{configuration}==""
    ATTRS{devnum}=="1"
    ATTRS{devpath}=="0"
    ATTRS{idProduct}=="0002"
    ATTRS{idVendor}=="1d6b"
    ATTRS{interface_authorized_default}=="1"
    ATTRS{ltm_capable}=="no"
    ATTRS{manufacturer}=="Linux 6.12.48 xhci-hcd"
    ATTRS{maxchild}=="2"
    ATTRS{power/active_duration}=="39530"
    ATTRS{power/autosuspend}=="0"
    ATTRS{power/autosuspend_delay_ms}=="0"
    ATTRS{power/connected_duration}=="39530"
    ATTRS{power/control}=="auto"
    ATTRS{power/level}=="auto"
    ATTRS{power/runtime_active_time}=="39489"
    ATTRS{power/runtime_status}=="active"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{product}=="xHCI Host Controller"
    ATTRS{quirks}=="0x0"
    ATTRS{removable}=="unknown"
    ATTRS{remove}=="(not readable)"
    ATTRS{rx_lanes}=="1"
    ATTRS{serial}=="xhci-hcd.1"
    ATTRS{speed}=="480"
    ATTRS{tx_lanes}=="1"
    ATTRS{urbnum}=="28"
    ATTRS{version}==" 2.00"

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb/xhci-hcd.1':
    KERNELS=="xhci-hcd.1"
    SUBSYSTEMS=="platform"
    DRIVERS=="xhci-hcd"
    ATTRS{driver_override}=="(null)"
    ATTRS{power/control}=="on"
    ATTRS{power/runtime_active_time}=="39544"
    ATTRS{power/runtime_status}=="active"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/axi/1000120000.pcie/1f00300000.usb':
    KERNELS=="1f00300000.usb"
    SUBSYSTEMS=="platform"
    DRIVERS=="dwc3"
    ATTRS{driver_override}=="(null)"
    ATTRS{power/autosuspend_delay_ms}=="5000"
    ATTRS{power/control}=="on"
    ATTRS{power/runtime_active_time}=="39544"
    ATTRS{power/runtime_status}=="active"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/axi/1000120000.pcie':
    KERNELS=="1000120000.pcie"
    SUBSYSTEMS=="platform"
    DRIVERS=="brcm-pcie"
    ATTRS{driver_override}=="(null)"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/axi':
    KERNELS=="axi"
    SUBSYSTEMS=="platform"
    DRIVERS=="simple-pm-bus"
    ATTRS{driver_override}=="(null)"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform':
    KERNELS=="platform"
    SUBSYSTEMS==""
    DRIVERS==""
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

Making use of the info in libinput/lavwc, maybe extending their matchers or adding custom udev rules might help

6by9 · 2025-09-23T17:46:57Z

Touch devices are fairly unique in the input subsystem in that you need to know which one is which in order to associate it with the appropriate display device. Plug in two mice or two keyboards and they normally apply to the entire desktop seat.

I must confess to having hoped initially to make this more contained in input subsystems that it touched, but USB HID device descriptors don't lend themselves to it.
The InterfaceProtocol has values defined for mice (2) and keyboards (1), but my keyboard registers two extra devices with type (0) as it appears the media and power controls don't fall within a keyboard definition. Trying to intercept just InterfaceProtocol 0 therefore still doesn't work.

Having talked to @cillian64 about it, it does appear that libinput can do something similar, thereby avoiding the maintenance hell of having to have device specific udev rules for every USB touch screen out there.

6by9 requested a review from P33M September 22, 2025 15:47

6by9 mentioned this pull request Sep 22, 2025

HID: usbhid: Insert USB bus/device ID into HID name #6356

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pelwell approved these changes Sep 22, 2025

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6by9 force-pushed the rpi-6.12.y-usbhid branch from a8d63bd to 18da0e8 Compare September 22, 2025 16:04

6by9 closed this Sep 23, 2025

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HID: usbhid: Insert USB bus/device ID into HID name #7061

HID: usbhid: Insert USB bus/device ID into HID name #7061

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HID: usbhid: Insert USB bus/device ID into HID name #7061

HID: usbhid: Insert USB bus/device ID into HID name #7061

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