Re: [RFC]Is usb port number fixed?

From: Wang YanQing
Date: Sat Apr 21 2012 - 01:57:55 EST


On Fri, Apr 20, 2012 at 08:32:37PM -0400, Alan Stern wrote:
> In this particular case, it is guaranteed that the left USB port will
> always be numbered as X-1.1:1.0 and the right port as X-1.2:1.0, where
> the number X may change from one boot to another. But the -1.1:1.0 and
> -1.2:1.0 parts will always be the same.
>
> This is because X is the bus number, which is allowed to change. The
> -1.1:1.0 and -1.2:1.0 values are port, configuration, and interface
> numbers. They will never change, because they come from the hardware.
Yes, configuration and interface come from the hardware,
but I don't know where the port come from, at least I don't think the port
comes from the same hardware with the configuration and interface, do you
mean port come from the hub?
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