想知道 libusb_bulk_transfer 错误代码 [英] wondering about libusb_bulk_transfer error code

问题描述

libusb_open(device, &deviceHandle);

<块引用>

返回 0

但是

libusb_bulk_transfer(deviceHandle, 0x81, data1, 512, &len, 0);

<块引用>

返回-5

所以我尝试使用 printf

查找错误 code -5

LIBUSB_ERROR_TIMEOUTLIBUSB_ERROR_PIPELIBUSB_ERROR_OVERFLOWLIBUSB_ERROR_NO_DEVICELIBUSB_ERROR_IOLIBUSB_TRANSFER_ERRORLIBUSB_ERROR_INTERRUPTEDLIBUSB_ERROR_ACCESSLIBUSB_ERROR_BUSYLIBUSB_ERROR_NO_MEMLIBUSB_ERROR_COUNTLIBUSB_ERROR_INVALID_PARAM

但是没有...而且在谷歌找不到任何地方...

libusb_bulk_transfer中的error code -5是什么意思?

帮帮我！

解决方案

LibUSB 错误代码可在 libusb 文档中找到，该文档可在线获取 这里.

函数libusb_error_name 和libusb_strerror 也可用于获取与错误代码对应的字符串.-5 是 LIBUSB_ERROR_NOT_FOUND :未找到实体.

Google 建议检查您是否已成功声明接口(您必须声明要使用的接口，使用 libusb_claim_interface 在做 IO 之前).

libusb_open(device, &deviceHandle);

returns 0

but

libusb_bulk_transfer(deviceHandle, 0x81, data1, 512, &len, 0);

return -5

so I try to find error code -5 using printf

LIBUSB_ERROR_TIMEOUT
LIBUSB_ERROR_PIPE
LIBUSB_ERROR_OVERFLOW
LIBUSB_ERROR_NO_DEVICE
LIBUSB_ERROR_IO
LIBUSB_TRANSFER_ERROR
LIBUSB_ERROR_INTERRUPTED
LIBUSB_ERROR_ACCESS
LIBUSB_ERROR_BUSY
LIBUSB_ERROR_NO_MEM
LIBUSB_ERROR_COUNT
LIBUSB_ERROR_INVALID_PARAM

But none... and can't find anywhere in google...

What's the meaning of error code -5 in libusb_bulk_transfer?

Help me!

解决方案

LibUSB error codes can be found in the libusb documentation, which is available online here.

The functions libusb_error_name and libusb_strerror can also be used to get a string corresponding to the error code. -5 is LIBUSB_ERROR_NOT_FOUND : Entity not found.

Google suggest checking that you have successfully claimed the interface (you must claim the interface you want to use, with libusb_claim_interface before doing IO).

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