#10857 NORM Opportu: XO-1 touchpad spews

[Zarro Boogs per Child]

#10857: XO-1 touchpad spews
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 Reporter:  mavrothal           |                 Owner:  wad                              
     Type:  defect              |                Status:  new                              
 Priority:  normal              |             Milestone:  Opportunity                      
Component:  hardware            |               Version:  Development build as of this date
 Keywords:  touchpad ALPS HGPK  |           Next_action:  diagnose                         
 Verified:  0                   |   Deployment_affected:  everyone!                        
Blockedby:                      |              Blocking:                                   
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 The XO-1 ALPS HGPK touchpad is known for its soft and hard packet spews
 and "big jumps". Although there are a couple of relevant open tickets
 #1407, #10373 that parts of this ticket could go to, I thought it might be
 better to open a new one.

 Post os802 builds and in-spite of the automatic re-calibration feature,
 appear to have more often issues.
 I'm Monitoring serio1 kernel messages over a period of time in 2 XO-1s
 running F11-os860, F14-os15/18 and XOpup-2.1

 For monitoring i trigger this script from rc.local
 {{{
 #!/bin/sh
 # get cpu load free memory and recalibration events every 5 minutes
 while [ 1 ] ; do
 sleep 300
 cat /home/olpc/.olpc-active-desktop >> /home/olpc/touchpad_full.log
 uptime >> /home/olpc/touchpad_full.log
 free >> /home/olpc/touchpad_full.log
 dmesg -c | grep "psmouse\ serio1\:" >> /home/olpc/touchpad_full.log
 echo " " >> /home/olpc/touchpad_full.log
 done
 }}}

 In a nutshell what I find is:[[BR]]
 a) that the spewing pattern may not be random[[BR]]
 b) that quite often spews are repetitive[[BR]]
 c) that re-calibration only remedies the issue for very short time and at
 times not at all[[BR]]
 d) that powering off the touchpad at regular intervals improves its
 behavior[[BR]]
 e) that spewing can be triggered.[[BR]]
 f) that adding clear tape over the touchpad area does not affect the
 frequency of the events[[BR]]
 g) renice-ing the touchpad to lower priority might have some effect.[[BR]]

 The logs suggest that on "normal use" it usually takes 5-10 minutes before
 any spews are detected. After that time one or more erratic events are
 appearing in almost every 5-min segment that there is some touchpad
 use.[[BR]]
 It would appear that CPU load or memory use is unrelated to the events and
 that spewing is proportional and cumulative of the touchpad use,
 particularly click-and-drag actions. [[BR]]
 Automatic re-calibration has little effect in the appearance of the next
 packet spew that very often comes in bunches. I have seen up to 8 re-
 calibration events in a 5 minutes segment.[[BR]]
 In contrast power-cycling the touchpad by echo-ing 0/1 to
 /sys/devices/platform/i8042/serio1/powered quenches spews for 5-10
 minutes.[[BR]]
 I used clear tape over the touchpad of one of my XO-1s, as the grapevine
 goes, but I could not see any significant difference in the frequency of
 the events.
 In contrast might be some improvement renicing kseriod and kpsmoused to
 the lowest priority but nothing dramatic.

 At any point erratic behavior can be triggered after 30-90 seconds of
 continuos click-and-drag action like drawing with small deliberate strokes
 in Paint or scratch or playing a game. I have seen packet spews as early
 as 87 seconds after boot started. Barely enough to open paint and start
 drawing.

 I'm not sure if this info can help in anyway to improve the driver or
 further diagnose the issue, but one idea may be to role back to the 2.6.25
 driver.
 It does not have the auto-recalibration feature but it would appear that
 has less frequent spews (though this should be verified).

-- 
Ticket URL: <http://dev.laptop.org/ticket/10857>
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