Hi,

On Sat, Jan 31, 2015 at 10:01 AM, Sebastien Bourdeauducq [off-list ref] wrote:

Hi,

among the many problems that the Baytrail-based Thinkpad Tablet 10 has under
Linux, the built-in Wacom digitizer does not work. I get the following
messages in the kernel log (with i2c_hid.debug=1):

[  593.224249] i2c_hid i2c-WCOM0008:00: Fetching the HID descriptor
[  593.224259] i2c_hid i2c-WCOM0008:00: __i2c_hid_command: cmd=01 00
[  593.243080] i2c_hid i2c-WCOM0008:00: HID Descriptor: 1e 00 00 01 ee 00 02
00 03 00 0a 00 00 00 00 00 04 00 05 00 6a 05 14 01 02 03 00 00 00 00
[  593.243110] i2c_hid i2c-WCOM0008:00: Could not register for WCOM0008:00
interrupt, irq = -1, ret = -22

That means that your tablet is the first one we (maybe only I) see
that uses a GPIO as an interrupt :)

Mika sent a patch recently which should solve your problem.
Can you give a try to the following patch?
https://patchwork.kernel.org/patch/5709961/

[  593.253422] i2c_hid: probe of i2c-WCOM0008:00 failed with error -22

What should I look at?

So if you can test the above patch, that would help. If it does not
work, we will need to check the DSDT of your tablet.

Cheers,
Benjamin