see subject, the RMI4 driver now uses that tool type
Created attachment 130366 [details]
large contact on pod
Here is an example of a large contact which the firmware would report as a palm. I just used the side of my palm.
I'm wondering if just fixing bug #94236 is enough rather than handling MT_TOOL_TYPE on top of the other palm detection we need anyway. But there are a few obstacles to that, specically: how is ABS_MT_TOUCH_MAJOR/MINOR used in the driver? Or rather, how am I supposed to use it?
According to the doc it *should* be in surface coordinates but the highest value in this recording is 25. Given 12 u/mm that would be a 2mm contact so you either have very very tiny hands or something is wrong here :)
In addition the axis max is 15, but the tool type palm is set at a major/minor of 13/9, so the max value seems to be a bit random.
As you may have seen ABS_MT_TOUCH_MAJOR/MINOR are set based on values that the firmware reports W/X and W/Y. The W is a representation of width, but it doesn't actually correspond with any sort of units.
Older devices which use RMI4 function 11 report both W values in a single byte. Each value being 4 bits. That's why the max is set to 15. Newer devices which use F12 now have use a byte for each W value. Newer devices should have a larger max.
The device I used to create the log used F12 which is why the actual values exceed the max.
ok, I implemented MT_TOOL_PALM support for now. Can I get you to try this branch please?
as for the major/minor handling, if there's some reliable way to converting from the firmware values to a useful value, that'd be good. I'd rather not use something that relies on DMI-specifics again.
Andrew, any chance you can test the branch I linked to?
Sorry about the delay. I gave it a quick test and it seems to suppress the pointer when I rub my palm on the touchpad. Performance feels similar to that of hid-multitouch which suppressed palms in the kernel. I'll keep testing and update if I find anything.
thanks for the testing. series is on the list now, I'll merge this after a while and we can fix bugs from then if you notice some.
Author: Peter Hutterer <email@example.com>
Date: Mon Apr 3 13:58:42 2017 +1000
touchpad: add MT_TOOL-based palm detection