We need adaptive communication speed!

[Antecer]

My device is compatible with HS and FS communication. It works in HS by default. When the HS handshake fails, it will automatically switch to the FS handshake. I hope usb-sniffer can work in HS mode by default and be backward compatible with FS communication capture. If working at a fixed communication speed, it will not meet my work needs in this case.

[ataradov]

There is no way to automatically switch the speed. First of all, there is no reliable way of doing this. The speed negotiation is a process that can be interpreted one way by the tool and the other way by the devices.

And the more important thing - it is no the goal of this tool. This is a debugging tool that is supposed to be used in a controlled environment.

When debugging a device that is capable of operating at a multiple speeds, debug operation at each speed separately with a host that you know can do HS or FS. This way you know what speed is expected to be negotiated and you can set it up ahead of time.

If you need to understand why the speed detection failed, you can use either speed, since all of that happens with line-state changes, which are the same regardless of the configured speed.

If you can describe a legitimate scenario where this is necessary, I'll be glad to hear it. But I pretty much guarantee that I won't do auto speed switch.