On Apr 14, 2015, at 5:48 PM, Terry Moore <[email protected]> wrote:
> Some other possibilities also come to mind:
>
> 1) perhaps you're supposed to take the report, combine the bytes, the speed,
> and the frame-rate to get the milliseconds, and then know that the bits on
> your high-speed device are faster than the bits on a full speed device.
The header file defines what GetBandwidthAvailable returns:
If the device is a high or super speed device, it will be the number of bytes
per microframe (125 µsecs). If it is a full
speed device, it will be the number of bytes per frame (1ms)
144 is what you’d expect of a low speed device which is consistent with what it
thinks the port is.
> 2) XHCI can have multiple root ports for different legacy speeds (on the
> physical USB 2 bus) [and some XHCI controllers found in the wild actually
> work that way]. If this particular XHCI for the "problem" port is of that
> kind, you may be getting data about the full speed root port instead of the
> (desired) high-speed root port.
If I’m remembering right all the lower speeds (high/full/low) are all handled
by the same controller for the XHCI this machine uses (built in Intel). Some of
the older machines might hand off high speed to the EHCI instead, but the log
indicates it is attached to the XHCI.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Usb mailing list ([email protected])
Help/Unsubscribe/Update your Subscription:
https://lists.apple.com/mailman/options/usb/archive%40mail-archive.com
This email sent to [email protected]
