Touchpad Bugs

Michael Stone michael at
Fri May 2 01:28:49 EDT 2008

Based on feedback from Carla, Bryan, and Kim, I recently undertook a
general review of touchpad, glide-sensor, and pen-tablet related
tickets. My grim results are listed in some detail in my post-script.
Here are some general observations:

1) The four major touchpad bug owners are jg, bernie, mlj, and dilinger.
Only jg and dilinger are presently regularly available.

2) Many touchpad bugs are closed as "fixed" or "duplicate" without solid
resolution comments. This is a problem since I'm concerned about both
software regressions and manufacturing variability.

3) Most of these bugs have not been updated in 3-6 months.

In conclusion, it seems that we have some work to do. [If you find
important tickets that I missed, please reply to this mail, CC me on the
ticket, and add the "touchpad" keyword to the bug.]



Relevant tickets

=== Sensitivity Problems

#4055     DBG    ???         (kernel's "touchpad magic numbers" may be wrong) 
                                [and are certainly hardware specific]

#4211     DBG    jg          (some [G1G1?] touchpads are _extremely_ sensitive)

#1875     ???    ???         (tap-to-click is too sensitive)
                                [resolution unclear; perhaps fixed by disabling tap-to-click?]

#1440     ???    jg          (hypersensitive CL-1 B3 touchpad)
                                [closed by jg with no resolution comment]

#1536     ???    ???         (touchpad needs calibration if it was touched during power-on)
                                [relnote; falsely marked as a dup of #1407]

#1407     PKG    dilinger    (automatic touchpad recalibration)
                                [cjb needs an updated kernel from dilinger]

#4032     DBG    dilinger    (Kids find touchpad hard to use)    !!!
                                [falsely closed as a dup of #4063]

#4063     FIN    cscott      (choose appropriate touchpad acceleration)

#3592     DBG    jg          (pencil on touchpad is hard to control)

=== Dielectric / Environmental Problems

#1068     ESC    ???         (trackpad doesn't like sweat)
                                [relnote; gen2]

#4183     ESC    ???         (touchpad doesn't like water/humidity[/saliva])
                                [inherent problem of capacitive sensors; partially ameliorated by addign a steel plate to the keyboard]

#5793     DBG    ???         (touch causes cursor to jump to screen edge _when sensor is cold_)

=== Non-specific Tickets

#5773     ???    holt        (unhappy G1G1 customer w/ non-specific touchpad failure)

#6011     DBG    quanta      (unprocessed field returns with touchpad problems)

=== Unexpected Cursor Motion

#2425     ???    ???         (rebound after fingerup on a B2)
                                [closed by mlj since B3 touchpads are "improved"]
#2804b    ???    dilinger    (mouse rebound)
                                [this _might_ be fixed, but the comments aren't convincing]

#743      FIN?   ???         (touchpad generates spurious coordinates)
                                [main issue fixed with a mylar sheet; status of sub-issues is unclear]
#2804a    PKG    dilinger    (spurious packets with (0,0) coordinates)

#2804c    ???    dilinger    (cursor jumps on finger-up)
                                [#2804 MNCharity suggested some excellent work-arounds]

#1949     ???    ???         (B2 with anisotropic touchpad; [i.e. touchpad axes are not equally sensitive])
#5575     ???    ???         (G1G1 MPs with anisotropic touchpad)
                                [#1949 closed as wontfix by mlj]
                                [#5575 Quanta and C. Setlow have found broken cables connecting the touchpad to its controller]
                                [Carla reported a machine whose touchpad problems disappeared after one of the resistive sensor cables was disconnected]

#4554     ESC    ???         (transitions from resistive to capacitive area cause jumps)
                                [pushed out by bernie]

#5761     DBG    dilinger    (mouse jumps to the top-left)

#5951     DBG    ???         (cursor flies off toward the edge of the screen)
                                [marked as a dup of #2804, but I'm unconvinced]

=== Misc. Software Faults & UI Failures

#4763     FIN    ???         (double clicks)
#6079     PKG    dilinger    (double clicks)
                                [Need to watch for regressions here]

#365      FIN    ???         (hot edges, hot corners, and the grabby key)
                                [Grabby key still not implemented]
#5629     ???    marco       (make hot corners configurable)

#6324     DSN    marco       (UI problems posed by hot corners)

#1263     ???    ???         (touchpad doesn't come back after resume until X starts)
                                [marked fixed by jg with no resolution comment]

#4732     ???    dilinger    (touchpad events which wake us up are dropped, not buffered)

#2203     FIN    ???         (touchpad, keyboard, and DCON are broken after resume on B2s)
#2186     FIN    jg          (cursor is frozen after resume on B2s) [closed as a dup of #2203]
#6184     ???    jg          (cursor is frozen after resume on one MP)

#1273     FIN?   ???         (PenTablet mode triggered with finger)
                                [unclear whether this was a software or hardware problem]

#5268     PKG    dilinger    (PenTablet disabled)

Key: ??? - status or author unknown
     TST - needs to be tested in a build
     BLD - needs to be put into a build
     PKG - pkg needs to be built
     DBG - debugging/diagnosis still needed
     DSN - design needed
     STK - stuck; a decision is needed about how to proceed
     SGN - a signoff is needed
     ESC - canceled or siginificantly reduced in priority
     FIN - successfully finished
     MSG - communication needed
     ROT - solution has bitrotted
     OWN - owner needed

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