Hi Alan, On Mon, Jul 18, 2016 at 6:09 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: >> 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. OK. >> 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. Nope. Looked for it. > 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. I've disabled it now and rebuilt the kernel. Yesterday was a replace-the-kitchen-faucet day, so I will be trying out the new usbcore module later today. I didn't vanish :) I'd do it now, but I'm in class: https://www.creativelive.com/courses/creating-painterly-photographs-kathleen-clemons -- 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
