Hi all. There's a number of reports for this problem (linux-kernel, "ELAN Touchscreen regression in recent 3.12 rc's? (USB)"; linux-usb, "problem with ELAN touchscreen"). Now, I own Yoga2Pro and can confirm that the bug exists up to 3.14. (confirmed in 3.14 release, 3.14-rc8, 3.13.6) Most of debugging features are off (I'm not sure if I got it right.. must they be on?). Also, the touchscreen is working and is not "electrically damaged" (I double-boot to original Win8.1 using rEFInd; note - I've attempted to forward it into VirtualBox running same Gentoo system, but USB forward failed). dmesg output is: [18036.787230] usb 2-7: new full-speed USB device number 117 using xhci_hcd [18038.800116] usb 2-7: unable to read config index 0 descriptor/start: -71 [18038.800129] usb 2-7: can't read configurations, error -71 [18038.953013] usb 2-7: new full-speed USB device number 118 using xhci_hcd [18038.965746] usb 2-7: ep 0x2 - rounding interval to 64 microframes, ep desc says 80 microframes [18040.966295] usb 2-7: USB disconnect, device number 118 sometimes it gets up for a second: (/var/log/messages excerpt) [201099.861467] usb 2-7: new full-speed USB device number 71 using xhci_hcd [201099.873867] usb 2-7: New USB device found, idVendor=04f3, idProduct=016f [201099.873871] usb 2-7: New USB device strings: Mfr=4, Product=14, SerialNumber=0 [201099.873872] usb 2-7: Product: Touchscreen [201099.873874] usb 2-7: Manufacturer: ELAN Note: I specially picked a quote from that log to ensure that it also doesn't gets up in 55+hour uptime. when its detected, it usually gets reconnected with incremented device ID: lsusb: Bus 002 Device 026: ID 04f3:016f Elan Microelectronics Corp. lsusb: Bus 002 Device 027: ID 04f3:016f Elan Microelectronics Corp. I've cloned Sarah's branch of xhci development kernel 'for-usb-next-2014-03-06' (which seems to be 3.14-rc5 inside) and.. same results! (Now, why I did that: there was a suggestion that change in usb enumeration helps.. It seems that the changes introduced by all 5 patches in Dan William's "[PATCH v2 0/5] usb: xhci: change default enumeration scheme and trivial cleanups" didn't helped here.. (checked that branch's code to see if patch is there, it seems to.. however xhci.c/xhci_address_device is different )) Also, attempts were made to check if removal of xhci-hcd.ko helps - didn't worked for builtin, modular, and modular 'blacklisted' with later load.. usbmon dump is available at http://www.everfall.com/paste/id.php?rxz976u2fz7p Gentoo, x64, udev-206. P.S. Excuse me for so much keywords/references in the post - there are other ppl looking for same references, it may be useful for them. -- Igor -- 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
