Re: [BUG] xhci_hcd: no USB3 SuperSpeed on IvyBridge Macbook

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On Thu, Apr 23, 2015 at 09:50:14PM +0100, Chris Bainbridge wrote:
> Hardware: IvyBridge Macbook (Panther Point PCH), 2 external USB3 ports
> Verified in kernels: 4.0.0+ (1fc1499), Debian 3.16.4
> 
> All USB3 devices appear as USB2 high-speed (480mbps) rather than USB3
> super-speed (5000mbps).

Are you sure you actually have a device that runs at that speed?  A USB
3 device can run at "low speed" and still be USB 3 compliant (backwards
compatibility issues ensure this.)

> Booting with nothing plugged in to the USB3 ports and then plugging in a single
> Sandisk Extreme USB3 flash drive shows the same behaviour, no "super-speed".
> The drive is capable of SuperSpeed:
> 
> # lsusb -v -d 0781:5580 | grep peed
>   SuperSpeed USB Device Capability:
>     wSpeedsSupported   0x000e
>       Device can operate at Full Speed (12Mbps)
>       Device can operate at High Speed (480Mbps)
>       Device can operate at SuperSpeed (5Gbps)
>       Lowest fully-functional device speed is Full Speed (12Mbps)

That's interesting, does it show up as a SuperSpeed device plugged into
any other machine?

thanks,

greg k-h
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