Linux – Ignoring other USB devices in a udev rule

linuxudevusb

Is it possible to create a udev rule for an USB device and ignore other USB devices?

I want my system to support HID USB touchscreen (hid.ko) and ignore HID devices such as keyboards, mice, etc.

Best Answer

By the time udev is running to handle creating the device, it's too late—the kernel has already attached the HID driver to the mouse/keyboard/etc.

Instead, you should be able to use the USB authorization framework (I've personally never used this, so I can't vouch it works). Basically, you tell Linux not to authorize new USB devices. Then you individually authorize each one by doing echo 1 > /sys/bus/usb/devices/DEVICE/authorized as root.

You can set the default to not authorized via the usbcore authorized_default=0 module parameter or the usbcore.authorized_default=0 kernel parameter (if USB isn't compiled as a module). Alternatively, you can do it on a per-bus basis, after boot, with echo 0 > /sys/bus/usb/devices/usbX/authorized_default.

Related Solutions

Udev rule for usb attach/detach not triggering

Your rule must give an absolute path for executable:

ACTION=="add", SUBSYSTEMS=="usb", RUN+="/usr/bin/touch /tmp/test"

Edit:

And if you want to execute a script, you must tell what shell will execute it:

ACTION=="add", SUBSYSTEMS=="usb", RUN+="/bin/sh /path/to/your/script"

Ubuntu USB Serial Devices – Udev Rule for Assigning Known Symlinks

This is untested in combination:

Add a udev rule to IMPORT{program}="/usr/local/sbin/unique-num /run/miner-counter 0 MINER_NUM" for your miners.

Then you could use a simple shell script, something like this somewhat tested program:

#!/bin/sh

if [ $# -ne 3 ]; then
    echo "Usage: $0 data-file initial var-name" >&2
    exit 1
fi

datfile="$1"
lockfile="$1.lck"
initial=$2
key="$3"

(
    flock -x 9
    num=$initial
    if [ -e "$datfile" ]; then
        read -r num < "$datfile"
    fi

    next=`expr $num + 1`;
    echo $next > "$datfile"

    echo "$key=$num"
) 9> "$lockfile"

Then you can use that udev environment variable to name your miners.

Best Answer

Related Solutions

Udev rule for usb attach/detach not triggering

Ubuntu USB Serial Devices – Udev Rule for Assigning Known Symlinks

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