Hello, After switching to a newer laptop my USB MIDI keyboard didn't work anymore. Other USB devices that I have (memory stick and mouse) work well. 2 out of 3 USB ports couldn't keep keyboard turned on (keyboard turns on for a second and then turns off). Only one USB port was able to keep keyboard powered correctly. When playing half of the midi events were not recorded due to some kind of lag. For example "note on" skipped and nothing was played or "note off" skipped and note keeped playing after releasing the key. I found out that when I disable USB 3.0 controller in BIOS then my MIDI USB keyboard works perfectly in any of the USB port that my Dell Latitude E7440 has. System log when connected to USB port that can't turn keyboard on: 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 40.375963] usb 2-2: new full-speed USB device number 3 using xhci_hcd 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 40.531185] usb 2-2: Device not responding to setup address. 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 40.738066] usb 2-2: Device not responding to setup address. 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 40.945350] usb 2-2: device not accepting address 3, error -71 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 41.100182] usb 2-2: new full-speed USB device number 4 using xhci_hcd 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 41.255220] usb 2-2: device descriptor read/64, error -71 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 41.513405] usb 2-2: device descriptor read/64, error -71 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 41.774971] usb 2-2: new full-speed USB device number 5 using xhci_hcd 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 41.775242] usb 2-2: Device not responding to setup address. 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 41.977570] usb 2-2: Device not responding to setup address. 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 42.184720] usb 2-2: device not accepting address 5, error -71 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 42.339716] usb 2-2: new full-speed USB device number 6 using xhci_hcd 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 42.351882] usb 2-2: device descriptor read/8, error -71 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 42.467194] usb 2-2: device descriptor read/8, error -71 02.01.17 0:41 karmo-Latitude-E7440 kernel [ 42.574581] usb usb2-port2: unable to enumerate USB device System log when connected to only USB port that can turn keyboard on but skips half of the events: 02.01.17 0:44 karmo-Latitude-E7440 kernel [ 225.570976] usb 2-1: new full-speed USB device number 8 using xhci_hcd 02.01.17 0:44 karmo-Latitude-E7440 kernel [ 225.740251] usb 2-1: New USB device found, idVendor=1235, idProduct=001b 02.01.17 0:44 karmo-Latitude-E7440 kernel [ 225.740253] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 02.01.17 0:44 karmo-Latitude-E7440 kernel [ 225.740254] usb 2-1: Product: Impulse 02.01.17 0:44 karmo-Latitude-E7440 kernel [ 225.740739] usb 2-1: can't set config #1, error -71 02.01.17 0:44 karmo-Latitude-E7440 mtp-probe checking bus 2, device 8: "/sys/devices/pci0000:00/0000:00:14.0/usb2/2-1" 02.01.17 0:44 karmo-Latitude-E7440 mtp-probe bus: 2, device: 8 was not an MTP device BR, Karmo -- 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
