On Wed, 01 Apr 2015 21:23:15 +0200 Ulf Brosziewski <ulf.brosziew...@t-online.de> wrote: > Yes, without some refactoring there won't be an elegant way. > pms_sync_elantech_v2 encodes some sync state in the 'flags' field > (ELANTECH_F_2FINGER_PACKET), but doing the same in the v3/CRC case might > be ugly.
Admittedly I am biased because I don't want to refactor ~2400 LOC to get my touchpad working but I don't think that crc enabled v3 touchpads use the debounce packet. I just installed Ubuntu and compiled the 3.19.3 linux kernel with added printk statements in the elantech_packet_check_v3 function on my laptop. In the linux kernel documentation [0] for elantech touchpads it says about the debounce packet: "Note on debounce: In case the box has unstable power supply or other electricity issues, or when number of finger changes, F/W would send "debounce packet" to inform driver that the hardware is in debounce status." I could not reproduce the unstable power supply but when switching the number of fingers on the touchpad no debounce packet is issued. Instead just the head and tail packets are registered and processed (unlike the OpenBSD driver which ignores the tail packet). This leads me to belief that v3/crc does not use debounce packets. Do you think this is possible/likely? There doesn't appear to be any official documentation in regard to elantech touchpads, hence I can't be certain. Nonetheless a refactor would obviously be beneficial but in the interim the patch might do a sufficient job. [0] https://www.kernel.org/doc/Documentation/input/elantech.txt
