On 9/1/20 10:36 AM, Alan Stern wrote: > On Tue, Sep 01, 2020 at 09:15:46AM -0700, Khalid Aziz wrote: >> On 8/31/20 8:31 PM, Alan Stern wrote: >>> Can you collect a usbmon trace showing an example of this problem? >>> >> >> I have attached usbmon traces for when USB hub with keyboards and mouse >> is plugged into USB 2.0 port and when it is plugged into the NEC USB 3.0 >> port. > > The usbmon traces show lots of errors, but no Clear-TT events. The > large number of errors suggests that you've got a hardware problem; > either a bad hub or bad USB connections.
That is what I thought initially which is why I got additional hubs and a USB 2.0 PCI card to test. I am seeing errors across 3 USB controllers, 4 USB hubs and 4 slow/full speed devices. All of the hubs and slow/full devices work with zero errors on my laptop. My keyboard/mouse devices and 2 of my USB hubs predate motherboard update and they all worked flawlessly before the motherboard upgrade. Some combinations of these also works with no errors on my desktop with new motherboard that I had listed in my original email: 2. USB 2.0 controller - WORKS 5. USB 3.0/3.1 controller -> Bus powered USB 2.0 hub - WORKS I am not seeing a common failure here that would point to any specific hardware being bad. Besides, that one code change (which I still can't say is the right code change) in ehci-q.c makes USB 2.0 controller work reliably with all my devices. -- Khalid
