Notes: This touch screen reports itself as a Wacom USB device. This should be handled by the wacom_wac.c driver in the kernel. The 0x5010 Product ID is still not explicitly listed in wacom_wac.c as of the latest Linux kernel v4.0-rc4. However, it appears that a catch-all entry, USB_DEVICE_WACOM(HID_ANY_ID), was added to wacom_wac.c beginning in Linux kernel v3.18. This catch-all entry allows for basic touch support.
Solution Needed: In order to get full support (e.g., multitouch), the wacom_wac.c needs to be updated with a description of the ThinkPad T550's Wacom device with Product ID 0x5010. Semi-functional workaround: Use a 3.18 or newer kernel. I used a v4.0-rc4 mainline kernel (https://wiki.ubuntu.com/Kernel/MainlineBuilds; http://kernel.ubuntu.com /~kernel-ppa/mainline/v4.0-rc4-vivid/) to workaround the issue on my Thinkpad T550, but I believe a kernel as early as 3.18 would work. My T550's screen accepts basic touches at least. Each touch is treated the same way it would be if it was a mouse cursor left-clicking at that spot (or left-button dragging if I do a drag). Workaround Note for Thinkpad T550 users: When I first booted the v4.0-rc4 kernel, my Wi-Fi stopped working. The newer kernel was looking for a newer iwlwifi-7065D-*.ucode firmware binary than what was installed in /lib/firmware in 14.04. To resolve this, I downloaded https://wireless.wiki.kernel.org/_media/en/users/drivers/iwlwifi-7265-ucode-23.15.10.0.tgz, unpacked it, and copied the iwlwifi*.ucode files into /lib/firmware. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-lts-utopic in Ubuntu. https://bugs.launchpad.net/bugs/1433444 Title: Thinkpad T550 touchscreen does not work Status in linux-lts-utopic package in Ubuntu: Confirmed Bug description: T: Bus=02 Lev=01 Prnt=01 Port=04 Cnt=02 Dev#= 7 Spd=12 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=056a ProdID=5010 Rev=00.14 S: Manufacturer=Wacom Co.,Ltd. S: Product=MultiTouch Sensor C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=16mA I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=00 Prot=00 Driver=(none) Bus 002 Device 007: ID 056a:5010 Wacom Co., Ltd Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x056a Wacom Co., Ltd idProduct 0x5010 bcdDevice 0.14 iManufacturer 1 iProduct 2 iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 34 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xe0 Self Powered Remote Wakeup MaxPower 16mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 0 No Subclass bInterfaceProtocol 0 None iInterface 3 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.11 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 537 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 2 ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.16.0-31-generic 3.16.0-31.43~14.04.1 ProcVersionSignature: Ubuntu 3.16.0-31.43~14.04.1-generic 3.16.7-ckt5 Uname: Linux 3.16.0-31-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.7 Architecture: amd64 CurrentDesktop: XFCE Date: Tue Mar 17 23:18:03 2015 InstallationDate: Installed on 2015-03-05 (13 days ago) InstallationMedia: Xubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1) SourcePackage: linux-lts-utopic UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-utopic/+bug/1433444/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
