#12221 NORM 4-softw: xo-4 touchscreen sometimes misses touch releases

[Zarro Boogs per Child]

#12221: xo-4 touchscreen sometimes misses touch releases
-------------------------+--------------------------------------------------
 Reporter:  pgf          |                 Owner:  pgf                              
     Type:  defect       |                Status:  new                              
 Priority:  normal       |             Milestone:  4-software                       
Component:  touchscreen  |               Version:  Development build as of this date
 Keywords:               |           Next_action:  diagnose                         
 Verified:  0            |   Deployment_affected:                                   
Blockedby:               |              Blocking:                                   
-------------------------+--------------------------------------------------
 it is possible to demonstrate that sometimes the touchscreen misses
 reporting ZF_TOUCHSTATE_UP events.

 turn on debug output in the touchscreen driver:
 {{{
 echo 1 > /sys/modules/zforce/parameters/debug
 }}}

  when the problem happens, the correct number of "zforce: s 0/1 up"
 messages won't be seen.

 to reproduce, tap two or three fingers on the screen at almost exactly the
 same time. i haven't yet determined the necessary conditions:  how many
 fingers, or whether it's related to the application of release.

 here's an example of a correct case:
 {{{
 [ 2613.921091] zforce: mt x 1163 y 702 p 100 s 1
 [ 2613.925466] zforce: new tid 725 s 1
 [ 2613.959140] zforce: mt x 1163 y 704 p 100 s 1
 [ 2613.975635] zforce: mt x 959 y 708 p 80 s 0
 [ 2613.982905] zforce: new tid 726 s 0
 [ 2613.992291] zforce: mt x 1163 y 705 p 100 s 1
 [ 2614.003388] zforce: mt x 959 y 707 p 80 s 0
 [ 2614.021323] zforce: mt x 957 y 734 p 80 s 0
 [ 2614.029693] zforce: s 1 up
 [ 2614.034830] zforce: s 0 up

 }}}

 here's an example of a failure:
 {{{
 [ 2743.300835] zforce: mt x 589 y 632 p 100 s 0
 [ 2743.305097] zforce: new tid 741 s 0
 [ 2743.326992] zforce: mt x 590 y 633 p 100 s 0
 [ 2743.358512] zforce: mt x 590 y 682 p 110 s 0
 [ 2743.362786] zforce: mt x 746 y 692 p 110 s 1
 [ 2743.368368] zforce: new tid 742 s 1
 [ 2743.377862] zforce: mt x 590 y 681 p 110 s 0
 [ 2743.385408] zforce: mt x 746 y 687 p 110 s 1

 }}}

 in this case, both "s 0 up" and "s 1 up" are missing, but sometimes only
 one is missed.

-- 
Ticket URL: <http://dev.laptop.org/ticket/12221>
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