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Translation(s): none

Models covered
Lenovo ThinkPad Tablet 8

- Screen: 8.4" Full HD touchscreen
- CPU: Intel Atom BayTrail Z3770 or Z3795
- RAM: 2GB or 4GB (LPDDR3 1067 onboard)
- Storage: 64GB or 128GB eMMC
- Video card: integrated Intel HD Graphics
- Wi-Fi: Broadcom BCM43241 rev B5 chipset (SDIO)
- Bluetooth: same Broadcom BCM43241 rev B5 (UART)
- GPS and Wireless LAN on some models

Overall Status

Legend :
= OK ; Unsupported(No Driver) ; = Error (Couldn't get it working); [?] Unknown, Not Test ; [-] Not-applicable
= Configuration Required; = Only works with a non-free driver and or firmware

Important Note

none

System

Feedback based on running a custom Linux Kernel 4.5 (4.5.0-rc6).

Display

The built-in display and the micro-HDMI output are automatically detected and are working properly out-of-the-box. However, hotplugging an external screen crashes the Gnome session and in fact the whole system if running with Wayland currently in Debian Stretch (March 7, 2016). The solution is to fallback to the X.org backend instead of Wayland for the moment, by editing the GDM configuration file:

 # vi /etc/gdm3/daemon.conf
 [daemon]
 # Uncoment the line below to force the login screen to use Xorg
 WaylandEnable=false

The session must then be restarted, the easiest way being to reboot the tablet.

Audio

• (not covered yet)

Mouse

• (not covered yet)

Power Management

• (not covered yet)

WiFi

• (not covered yet)

Bluetooth

Bluetooth is provided by an on-board SDIO Broadcom chipset BCM43241 rev B5. It requires a binary firmware file to be enabled. This chipset is supported starting with Linux kernel 4.6 but it still requires the upstream BlueZ stack, which is not (yet) packaged in Debian for the time being (early August 2016).

Support for the BCM43241 rev B5 chipset was added in early March 2016 in the bluetooth-next kernel development tree with the following commit: Add BCM2E55 ACPI ID used in Lenovo ThinkPad Tablet 8. It has been integrated officially in Linux kernel version 4.6.

Enabling this Bluetooth chipset is done via the new btattach command, released in BlueZ version 5.37. Until this version is packaged in Debian, instructions about how to build it can be found here Building Bluez 5.37 on Debian Jessie. Once compiled, the btattach command is found in "debian/tmp/usr/bin/". A first experimental package is being uploaded based on version 5.40, as of August 2016..

Then the binary firmware file must be copied in /lib/firmware/brcm/BCM.hcd and can be found on the original Windows partition. It has the following format "BCM4324B5_vvv.www.xxx.yyyy.zzzz.hcd" with the current version being BCM4324B5_002.006.006.0601.1170.hcd .

 # cp ./BCM4324B5_002.006.006.0601.1170.hcd /lib/firmware/brcm/BCM.hcd

Finally, Bluetooth can be enabled with btattach (built previously), with the parameter /dev/ttySx possibly varying (in my case /dev/ttyS1 is the proper one working):

# btattach --bredr /dev/ttyS1 -P bcm &
Attaching BR/EDR controller to /dev/ttyS1
Switched line discipline from 0 to 15
Device index 0 attached

Upon each reboot, btattach will have to be entered once again until btattach is fully supported by the Debian boot scripts.

For some reasons I can't explain, I have to keep the Gnome Bluetooth settings window open for Bluetooth to remain active properly. If I close the window, Bluetooth will disable itself after a short amount of time, this is really annoying and I would need to dig deeper to understand what's going on...

The hciconfig command can be used to check that the chipset is properly enabled:

$ hciconfig -a
hci0:   Type: BR/EDR  Bus: UART
        BD Address: B0:10:41:B8:16:6C  ACL MTU: 1021:8  SCO MTU: 64:1
        UP RUNNING PSCAN ISCAN 
        RX bytes:1251925 acl:41541 sco:0 events:1191 errors:0
        TX bytes:39965 acl:56 sco:0 commands:804 errors:0
        Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
        Link policy: RSWITCH SNIFF 
        Link mode: SLAVE ACCEPT 
        Name: 'thinkpad8'
        Class: 0x10011c
        Service Classes: Object Transfer
        Device Class: Computer, Unknown (reserved) minor device class
        HCI Version: 4.0 (0x6)  Revision: 0x3492
        LMP Version: 4.0 (0x6)  Subversion: 0x4606
        Manufacturer: Broadcom Corporation (15)

and other information can be checked with dmesg:

$ dmesg | grep Bluetooth
 Bluetooth: Core ver 2.21
 Bluetooth: HCI device and connection manager initialized
 Bluetooth: HCI socket layer initialized
 Bluetooth: L2CAP socket layer initialized
 Bluetooth: SCO socket layer initialized
 Bluetooth: HCI UART driver ver 2.3
 Bluetooth: HCI UART protocol BCM registered
 Bluetooth: HCI UART protocol QCA registered
 Bluetooth: hci0: BCM: chip id 90
 Bluetooth: hci0: BCM (002.006.006) build 0000
 Bluetooth: hci0: BCM (002.006.006) build 1170

System Summary

lspci

00:00.0 Host bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series SoC Transaction Register (rev 0d)
00:02.0 VGA compatible controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display (rev 0d)
00:14.0 USB controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series USB xHCI (rev 0d)
00:1a.0 Encryption controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Trusted Execution Engine (rev 0d)
00:1f.0 ISA bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Power Control Unit (rev 0d)

lsusb

lsusb -v | grep -E '\<(Bus|iProduct|bDeviceClass|bDeviceProtocol)' 2>/dev/null

USB Host controllers entries (without OHCI, UHCI, EHCI) are removed too.

Resources

Attachments

Some configuration files and sample outputs.

Useful Links

Credits