On Mon, 18 Jul 2016, Bruce Korb wrote: > On Mon, Jul 18, 2016 at 2:24 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > This is not surprising, because the problem probably stems from the > > xHCI host controller in your computer, not from the hub. > > Gigabyte is supposed to make reliable motherboards. > Haven't been trying to use USB3 until now, but still.... > > Given the repeatability, maybe I can dig into where stuff is going awry. > Maybe I can trace down how the bogus speed information is derived. If my guess was correct, there is no bogus speed information. > I do not believe "Link Power Management" is enabled, but don't know > exactly how to tell, either. It would not be terribly hard to make xhci_hcd > more noisy. LPM is enabled by default. You can turn it off in later kernels by adding a quirk entry, but I believe 4.1 doesn't include the LPM quirk. On the other hand, you can turn off all LPM in 4.1 very easily by editing the usb_device_supports_lpm() routine in drivers/usb/core/hub.c. Make it return 0 immediately. That will be an easy way to tell whether my guess was right. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
