-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi,
I filed this as [https://bugs.freedesktop.org/show_bug.cgi?id=80470]. But perhaps worthy of maillist discussion... 1) The Kernel spec says multitouch devices should give ABS_X and ABS_Y events as well as ABS_MT_POSITION_X. [http://lists.x.org/archives/xorg/2013-July/055823.html] [https://bugs.freedesktop.org/show_bug.cgi?id=64029] 2) Many drivers (maybe even most?) for Android devices don't give ABS_X. I've personally played with Note 8 (synaptics_s7301 touchscreen driver), Nexus 5 (synaptics RMI4 drivder). I've looked at several other drivers (various Atmel MaXTouch, there is a mainline atmel_mxt_ts driver which does the right thing but seems devices often use older mxt224 drivers...). 3) Its not clear if many drivers are destined for mainline (Android looks like a fragmented and horrid dev scene compared to GNU/Linux). The device turnover is so fast. 4) The cause here is probably the Android docs: https://source.android.com/devices/tech/input/touch-devices.html#touch-device-classification which suggest (or at least imply) its OK for multitouch to not give ABS_X. 5) Fixing these upstream is a noble goal but difficult to have much impact---I've grabbed the cyanogenmod sources for my Note 8 and Nexus 5 with the thought to to look into doing this. But even if I fix these two drivers, it is not likely to reach many people. 6) Its much easier to compile a new xf86-input-evdev than to recompile and replace an Android OS. For example, I have a standard Fedora 20 in a chroot on my devices, which can talk to the framebuffer, even with (essentially) the out-of-box OS (called "ROM" in Android community)... Pen works great, just no touchscreen b/c of this. - ---------------------- Given the above, I think it might be more pragmatic to work around the the ABS_X issue. We could still give a (WW) warning (instead of an error) pointing out its contrary to kernel spec. I'm hopeful that such a workaround would involve changes only to evdev.c. Please advise if you think that's not the case (so I can decide whether to tackle this or 5) above). thanks, Colin - -- Colin Macdonald University Lecturer in Numerical Methodologies Tutorial Fellow at Oriel College University of Oxford -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJTqUkhAAoJEAzlCRPFMm7lsmEH/2j+Ywed9fH1I9GkBcxgoov+ UuCm+MQGAcTFIvbnZu6ETPehzz5fVRMz5GkU8DGGzPjJFuqE9hzEZ/oanM8jB7Ac ei0CQz3vod7es78lgq1T/fzSS6+fuJBkrz+5Hr4ENXh9OzaAmkVy6bsawRZMAAmX A/Qkpukm4TdnYatkGgcNYGi/VXqRA95pYXG8ocZg5IWifxZuCQGIIsBuTp+cjIFk I7bsFPfRYRMtNzt/aPUtGc4d/MEFmyvSMGNvaKD0SrNnn/qg8Fg9XeSVVMmK2yS5 qm84RswgDdzJY95T+FFF3vV152oTU7RiYX5yCijn+sY3qmWsNli3PWhlWTZ7OeU= =p41R -----END PGP SIGNATURE----- _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel
