On Tue, 12 Sep 2017, Bruce Korb wrote: > Some interesting progress. This time, I tried plugging my mouse > directly into the switch, bypassing the hub. The mouse works. However, > going through *either* of my two 3.0 hubs causes the mouse to *not* > work, despite the fact that other devices work fine going through the > hub. > > So, I unplugged and re-plugged my G400 mouse into that switch. > I then made sure the mouse was still responded to (it was) > and finally unplugged it again. > I did that over a 14 second period from 553.78 thru 566. > > Next, I plugged the hub back in. It has 7 external ports and one more > that is used to cascade the second VIA chip. After loading those up, > it found the G500 mouse that I had left plugged in. These entries > in dmesg are at 577 through 579 seconds. > > At 582.6 seconds, I plugged in the G400 mouse into the hub. > I futzed with it for a while, but it would not work. > > At 595.6 seconds, I removed my keyboard from the back of the computer > and plugged it into the switch. works fine. At 603.7 seconds, the mouse > is now plugged back into the back usb port and all is working (G500 aside). > > While all of this was going on, I was catting /sys/kernel/debug/usb/usbmon/2u > into a file. > > Now, what? :) Thank you!! This raises some questions: Can you eliminate the switch entirely as the cause? What happens if you plug the mouse into the USB-3 hub and plug the hub directly into the computer (bypass the switch)? What happens if you plug the keyboard into the USB-3 hub (either with or without the switch)? It's clear from the usbmon traces that the computer isn't getting any responses to the interrupt URBs (those responses are what the mouse uses to send back data about button clicks and motions). But if the packets were simply lost, it would show up as an error. It would be nice to know what's going on at each side of the hub. No way to do that without special hardware, though. 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
