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我想与 USB 设备通信并将数据发送到 USB 设备。我能够找到该设备，但是在将设备与它提供的内核驱动程序连接时USB Error: Resource Busy。以下是我的代码：

import usb

dev = usb.core.find(idVendor=0x0403, idProduct=0x6001)
dev.set_configuration()

cfg = dev.get_active_configuration()

dev.attach_kernel_driver(interface)

interface_number = cfg[(0, 0)].bInterfaceNumber
alternate_settting = usb.control.get_interface(interface_number)
intf = usb.util.find_descriptor(
    cfg, bInterfaceNumber=interface_number,
    bAlternateSetting=alternate_setting)

ep = usb.util.find_descriptor(
    intf, custom_match=lambda e:
    usb.util.endpoint_direction(e.bEndpointAddress) == usb.util.ENDPOINT_OUT)

dev.detach_kernel_driver(interface)

ep.write("\r" + linea1[:19] + "\n\r" + " " * (20 - len(linea2)) + linea2)
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1 回答 1

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假设您使用 Linux 并libusb-1.0作为PyUSB的后端库。

根据libusb 文档：

// Detach a kernel driver from an interface.
// If successful, you will then be able to claim the interface and perform I/O.
int libusb_detach_kernel_driver (libusb_device_handle *dev, 
                                 int interface_number)  

// Re-attach an interface's kernel driver, which was previously 
// detached using libusb_detach_kernel_driver().
int libusb_attach_kernel_driver(libusb_device_handle *dev,
                                int interface_number)

因此，基本上，您需要先调用detach_kernel_driver 以从设备接口中分离已连接的内核驱动程序（如果有），以便您可以在代码中与它通信（它是您的代码或某些内核驱动程序与设备接口通信）。完成后，您可能需要再次调用attach_kernel_driver重新附加内核驱动程序。

如果您可以确保没有为给定设备加载内核驱动程序（或在运行代码之前手动卸载它），我相信没有必要调用任何这些 C 函数/Python 方法。

编辑：

我刚刚得到了这段代码（基于你的示例）工作。注意：为简单起见，我将 0 硬编码为detach_kernel_driver和的接口编号attach_kernel_driver- 我想你应该让它更聪明。

import usb

dev = usb.core.find(idVendor=0x0403, idProduct=0x6001)

reattach = False
if dev.is_kernel_driver_active(0):
    reattach = True
    dev.detach_kernel_driver(0)

dev.set_configuration() 
cfg = dev.get_active_configuration() 

interface_number = cfg[(0,0)].bInterfaceNumber 
alternate_settting = usb.control.get_interface(dev, interface_number) 
intf = usb.util.find_descriptor(cfg, bInterfaceNumber = interface_number, 
                            bAlternateSetting = alternate_settting) 

ep = usb.util.find_descriptor(intf,custom_match = \
      lambda e: \
    usb.util.endpoint_direction(e.bEndpointAddress) == \
    usb.util.ENDPOINT_OUT) 
ep.write("test\n\r")

# This is needed to release interface, otherwise attach_kernel_driver fails 
# due to "Resource busy"
usb.util.dispose_resources(dev)

# It may raise USBError if there's e.g. no kernel driver loaded at all
if reattach:
    dev.attach_kernel_driver(0)
于 2012-09-22T10:59:01.853 回答