Debugging touch input problem
daniel.dandrada at canonical.com
Thu Sep 26 13:32:25 UTC 2013
On 26/09/13 02:52, Neal Peacock wrote:
> I'm running down a touch screen input problem and I'm trying to figure
> out the right place to look. I am porting ubuntu touch and the using
> mir. My last issue is the touch screen input. I was getting some
> very erratic results and I'm trying to figure out where it breaks.
> The screen will react a little to touches but not accurately and most
> of the gestures do not work, the few that will are sporadic. I have
> dumped out the touch results from the kernel and all the x,y and id
> values looks correct as far as I can tell. This driver works under
> LXDE and Android. lsof seems to show unity is the only process
> watching these events and it looks like the mir library might be what
> actually handles input.
> Is the mir server what handles touch input?
Yes, it has android-input inside it.
> I've been checking through the source and I see a references to the
> Android touch input code. I tried to enable the input report log but
> I don't seem to see any output with the upstart logs or in logcat.
> Where does that report go?
> Does the Android container need to have some touch input service
> running for it to work? I can't see a service an obvious name.
> Any help or thoughts appreciated, thank you.
So, if I understood you correctly you're trying it out on a new device?
If that's the case it might be that you didn't provide a .idc file for
your touchscreen (I guess idc stands for "input device configuration").
Take a look at InputDevice.cpp and its log messages.
Running mir_demo_standalone_inputfilter as root is the best way to
diagnose input issues. If you're using the latest mir (from bzr repo),
to get log messages from android-input you will also have to set a
ANDROID_LOG_TAGS environment variable appropriately. Set it to "*:v" to
get the most verbose log.
More information about the Mir-devel