Making sense of i2c

Colin McKinnon colin.mckinnon at
Sun Jan 29 00:59:05 UTC 2017

Hi all,

I've now got everything working - albeit on an older version of Ubuntu...

Story so far:

- Fedora 25 (4.8 and 4.9 kernels) - no touchscreen, everything else OK (and
very impressed with Wayland

- Ubuntu 14.04 (4.4 kernel) - touchscreen works, bit no wifi :(

Fedora decided to crash corrupting both / and /home filesystems. So I
decided to have another go with Ubuntu. A slight hiccup along the way as I
did not want to use LVM, and the ubuntu installer would not touch the
volume group Fedora had created. A quick `vgremove fedora` at the command
line fixed that. So install was relatively painless (but OMG - the
installer take a ridiculous amount of time to go back to a previous page or
to quit while not apparently waiting for anything!). I used a cable
connection to my LAN to get internet access during the install.

Checking the logs, I could see that the ath10k_pci driver was loading, but
reporting failures "could not fetch firmware file

So the kernel module was loading OK - I just needed newer firmware. This is
already available, packaged up for Ubuntu/Debian/Mint at

Installed these - and bingo - Wifi!

I did not want the ever helpful package manager to upgrade the kernel (and
thereby break the touch screen - which I had already determined failed in
16.04 when scanning the i2c bus, just like Fedora 25), hence I got a list
of the kernel packages from `dpkg --list | grep kernel`, and told dpkg to
'hold' then. I'm not sure if that will prevent the kernel update, but I'm
keeping my fingers crossed.
Since I've now posted on Redhat's bugzilla (and will eventually want to
upgrade this) I'll have a play around to see if I can narrow down which
kernel introduced the problem - but that's enough excitement for one week.


On 15 January 2017 at 11:58, Colin McKinnon <colin.mckinnon at>

> Hi all,
> I bought my daughter a Lenovo Yoga 510-14AST for Christmas. Everything
> works in Linux (Fedora 25) except for the touchscreen.
> Its not appearing as a USB device. At startup there is an error as it
> scans the i2c bus (which seems a likely place to find the device).
> Its currently running dual-boot with MSWindows. There I can see that the
> synaptic.sys driver is loaded, but I don't know how to divine any further
> details on how it is plumbed.
> C.

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