Udev规则不适用于Ubuntu 12.04上的libusb [英] Udev rules are not working for libusb on Ubuntu 12.04

问题描述

我使用的是Ubuntu 12.04.5 LTS x86_64.

I'm on Ubuntu 12.04.5 LTS, x86_64.

我有一个使用libusb与计算机通信的USB设备. 将其插入计算机并运行通信程序后，出现以下错误:

I've a usb device that uses libusb to communicate with the computer. Once I plug it into the computer and run the communication program I get the following error:

libusb couldn't open USB device /dev/bus/usb/008/004: Permission denied.
libusb requires write access to USB device nodes.
libusb failed to find the Optotrak USB device.  Are you sure you have set the udev permissions correctly?

因此，如果我按如下所示对/dev/bus/usb/008/004进行chmod修改:

So if I chmod the /dev/bus/usb/008/004 as follows:

sudo chmod 777 /dev/bus/usb/008/004

，然后再次运行通信程序，则设备可以正常运行. 问题在于，每次插入设备时，最后一个数字都会更改，因此每次USB总线时我都必须使用chmod，但是由于并非所有用户都知道管理员密码，所以这是一个问题.

and run the communication program again, then the device works perfectly. The problem is that every time I plug the device, the last number changes, so I should have to chmod every time the usb bus, but since not all users know the administrator password this is a problem.

因此，制造商建议如下编辑udev规则.在/etc/udev/rules.d内创建一个12-ndi-rules:

So the manufacturer suggest to edit the udev rules as follows. Create a 12-ndi-rules inside /etc/udev/rules.d :

BUS=="usb", SYSFS{idVendor}=="0403", SYSFS{idProduct}=="da77", GROUP="plugdev"

(我已经与lsusb确认SYSFS是正确的)

(I've checked with lsusb that SYSFS are correct)

lsusb 

Bus 008 Device 004: ID 0403:da77 Future Technology Devices International, Ltd 

，然后重新加载规则:

sudo udevadm control --reload-rules

但仍然未正确设置总线008/004的权限.

but still the permissions for bus 008/004 are not correctly set.

如何在每次重新启动时使这些规则保持不变?如果更改USB设备的端口，我也希望使它们永久化.

How do I make these rules permament at every reboot? I would also like to get make them permanent also if I change the port of the usb device.

推荐答案

除非您拥有真正的udev，否则规则是错误的，应该是:

Unless you have a really old udev, the rule is wrong, it should be :

SUBSYSTEM=="usb", ATTR{idVendor}=="0403", ATTR{idProduct}=="da77", GROUP="plugdev"

将规则放入/etc/udev/rules.d/中的文件是使其永久化的正确方法.

Putting the rule in a file in /etc/udev/rules.d/ is the correct way to make it permanent.

您可以在规则文件中添加的其他内容是在手册页中.

Other things you can put in a rule file are in the man page.

这篇关于Udev规则不适用于Ubuntu 12.04上的libusb的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！