如果 USB 设备不兼容 USB 2.0,可能会出现什么问题?
我有一个全速设备,将最大数据包大小指定为 256 字节。这不符合 USB 标准,因为全速设备的最大数据包大小应为 64 字节。我可以很好地读取(ReadFile)和写入(WriteFile)到设备,但我想知道是否可能会出现一些我没有看到的问题,除了跨多个 USB 帧写入可能会影响性能( 1毫秒)?我不是一个真正的 USB 专家,所以任何建议将不胜感激。
I have a Full Speed device that specifies the max packet size as 256 bytes. This is not USB compliant since the maxiumum packet size for a Full Speed Device should be 64 bytes. I can read (ReadFile) and write (WriteFile) to the device just fine, but I'm wondering if there could be issues that could arise that I'm just not seeing other than maybe a performance hit from writing across multiple usb frames (1ms)? I'm not really a USB expert, so any advice will be appreciated.
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这就是所谓的“希望合规”策略。
根据经验,我可以告诉您,您的设备将使各种嵌入式主机崩溃并导致其他主机损坏。 (大多数控制器上的缓冲区溢出,预期数据包大小为 64,并且使用了较差的软件。
这些包括不同的设置盒、电话等
。此外,像这样的与 Nec hcd 配合使用的 hack 可能不适用于 Intel 控制器。
This is whats called the "compliant by hope" strategy.
From experience I can tell you that your device will crash a wide range of embedded hosts and cause corruption on others. (buffer overflows on most controllers where expected packet size is 64 and poor software is used.
These include different setup boxes, phones, etc.
Also, hacks like these, that work with a Nec hcd, might not work with an Intel one.