#11543 NORM 1.75-so: Keyboard input out of sync / queued

Zarro Boogs per Child bugtracker at laptop.org
Tue Dec 13 13:06:20 EST 2011


#11543: Keyboard input out of sync / queued
-----------------------------+----------------------------------------------
 Reporter:  martin.langhoff  |                 Owner:  pgf          
     Type:  defect           |                Status:  new          
 Priority:  normal           |             Milestone:  1.75-software
Component:  keyboards        |               Version:  not specified
 Keywords:                   |           Next_action:  diagnose     
 Verified:  0                |   Deployment_affected:               
Blockedby:                   |              Blocking:               
-----------------------------+----------------------------------------------
 Just got OS19 + Q4C07, SKU 202, into a very strange condition.

 Booted to Sugar, opened Terminal, and discovered that by pressing up-arrow
 twice, with about .5 between key presses, I would get: first one step back
 in bash history (on first keypress), then a fast scroll up over a dozen or
 so bash history entries on the second keypress.

 With echo 9 >  /proc/sys/kernel/printk ; echo 1 >
 /sys/module/olpc_keyboard/parameters/debug and dsd's help looking at this,
 we found that we'd get E0 48 (up arrow key down) on first keypress, then
 e0 C8 (up arrow key up) on the second one. So the host thinks the key is
 down.

 Once in that state, something seemed to be buffering keys, and releasing
 them after a few more keystrokes. We say up to around 8 key presses
 buffered.

 We saw the same effect in a VT.

 CC'ing Mitch, because this could be related buffering at the SP.

 There is no "preserve wakeup keypress ECO" on this unit.

-- 
Ticket URL: <http://dev.laptop.org/ticket/11543>
One Laptop Per Child <http://laptop.org/>
OLPC bug tracking system


More information about the Bugs mailing list