Chromium only shows proper touchscreen behavior when the supplied ID argument is 7 in the case of the below devices. Note that the xinput IDs are subject to change during a reboot, so I can't just use 7 all the time.
I understand I can whitelist manufacturer strings but I would like something reliable that always works and doesn't depend on manufacturer strings staying the same. DEVICE 1: Touchscreen Hardware on device 1 (reported by xinput): ? Virtual core pointer id=2 [master pointer (3)] ? ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? ? ADS7846 Touchscreen id=9 [slave pointer (2)] ? ? NHD Newhaven Display id=7 [slave pointer (2)] ? Virtual core keyboard id=3 [master keyboard (2)] ? Virtual core XTEST keyboard id=5 [slave keyboard (3)] ? 30370000.snvs:snvs-powerkey id=6 [slave keyboard (3)] ? Dell Dell USB Entry Keyboard id=8 [slave keyboard (3)] /dev/input/touchscreen0 -> /dev/input/event1 udevadm info --query=property --name=/dev/input/event1 DEVLINKS=/dev/input/by-id/usb-NHD_Newhaven_Display-event-if00 /dev/input/by-path/platform-ci_hdrc.0-usb-0:1:1.0-event /dev/input/touchscreen0 DEVNAME=/dev/input/event1 DEVPATH=/devices/soc0/soc/30800000.aips-bus/30b10000.usb/ci_hdrc.0/usb1/1-1/1-1:1.0/0003:0461:0022.005C/input/input93/event1 ID_BUS=usb ID_INPUT=1 ID_INPUT_TOUCHSCREEN=1 ID_MODEL=Newhaven_Display ID_MODEL_ENC=Newhavenx20Displayx20 ID_MODEL_ID=0022 ID_PATH=platform-ci_hdrc.0-usb-0:1:1.0 ID_PATH_TAG=platform-ci_hdrc_0-usb-0_1_1_0 ID_REVISION=0100 ID_SERIAL=NHD_Newhaven_Display ID_TYPE=hid ID_USB_DRIVER=usbhid ID_USB_INTERFACES=:030102: ID_USB_INTERFACE_NUM=00 ID_VENDOR=NHD ID_VENDOR_ENC=NHD ID_VENDOR_ID=0461 LIBINPUT_CALIBRATION_MATRIX=1.066870 -0.005907 -0.026620 0.007245 -1.136364 1.046200 LIBINPUT_DEVICE_GROUP=3/461/22:usb-ci_hdrc.0-1 MAJOR=13 MINOR=65 SUBSYSTEM=input USEC_INITIALIZED=514876494495 DEVICE 2: Touchscreen Hardware on device 2 (reported by xinput): ? Virtual core pointer id=2 [master pointer (3)] ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? Silicon Integrated System Co. SiS HID Touch Controller Mouse id=8 [slave pointer (2)] ? Silicon Integrated System Co. SiS HID Touch Controller Touchscreen id=7 [slave pointer (2)] ? ADS7846 Touchscreen id=9 [slave pointer (2)] ? Virtual core keyboard id=3 [master keyboard (2)] ? Virtual core XTEST keyboard id=5 [slave keyboard (3)] ? 30370000.snvs:snvs-powerkey id=6 [slave keyboard (3)] /dev/input/touchscreen0 -> /dev/input/event3 (event1 seems like the correct touchscreen though, based on the udevadm output) udevadm info --query=property --name=/dev/input/event1 DEVLINKS=/dev/input/by-path/platform-ci_hdrc.0-usb-0:1:1.0-event /dev/input/touchscreen0 /dev/input/by-id/usb-Silicon_Integrated_System_Co._SiS_HID_Touch_Controller-event-if00 DEVNAME=/dev/input/event1 DEVPATH=/devices/soc0/soc/30800000.aips-bus/30b10000.usb/ci_hdrc.0/usb1/1-1/1-1:1.0/0003:04E7:1080.0001/input/input1/event1 ID_BUS=usb ID_INPUT=1 ID_INPUT_HEIGHT_MM=136 ID_INPUT_TOUCHSCREEN=1 ID_INPUT_WIDTH_MM=215 ID_MODEL=SiS_HID_Touch_Controller ID_MODEL_ENC=SiSx20HIDx20Touchx20Controller ID_MODEL_ID=1080 ID_PATH=platform-ci_hdrc.0-usb-0:1:1.0 ID_PATH_TAG=platform-ci_hdrc_0-usb-0_1_1_0 ID_REVISION=0100 ID_SERIAL=Silicon_Integrated_System_Co._SiS_HID_Touch_Controller ID_TYPE=hid ID_USB_DRIVER=usbhid ID_USB_INTERFACES=:030000: ID_USB_INTERFACE_NUM=00 ID_VENDOR=Silicon_Integrated_System_Co. ID_VENDOR_ENC=Siliconx20Integratedx20Systemx20Co. ID_VENDOR_ID=04e7 LIBINPUT_CALIBRATION_MATRIX=1.066870 -0.005907 -0.026620 0.007245 -1.136364 1.046200 LIBINPUT_DEVICE_GROUP=3/4e7/1080:usb-ci_hdrc.0-1 MAJOR=13 MINOR=65 SUBSYSTEM=input USEC_INITIALIZED=8612683
