Created attachment 54331 [details] [review]
Proposed patch, reverting the guilty commit.

(Love it when that happens…)

The following commit broke synaptics on powerpc (e.g. on iBook G4 with appletouch):
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commit 13543b156d78bc4d01a19844a5ee8f283269621b
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Sun Mar 20 09:28:45 2011 +1000

    eventcomm: replace synaptics-custom TEST_BIT with server's BitIsOn.
    
    Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
    Reviewed-by: Cyril Brulebois <kibi@debian.org>
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This was reported in: http://bugs.debian.org/648488

I was also able to reproduce it on such a machine, and got that after this commit:
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$ grep appletouch /var/log/Xorg.0.log
[   828.530] (II) config/udev: Adding input device appletouch (/dev/input/event5)
[   828.530] (**) appletouch: Applying InputClass "evdev touchpad catchall"
[   828.530] (**) appletouch: Applying InputClass "touchpad catchall"
[   828.531] (II) Using input driver 'synaptics' for 'appletouch'
[   828.531] (**) appletouch: always reports core events
[   828.532] (EE) PreInit returned 11 for "appletouch"
[   828.532] (II) config/udev: Adding input device appletouch (/dev/input/mouse1)
[   828.532] (**) appletouch: Applying InputClass "touchpad catchall"
[   828.533] (II) Using input driver 'synaptics' for 'appletouch'
[   828.533] (**) appletouch: always reports core events
[   828.533] (EE) PreInit returned 11 for "appletouch"
---

as opposed to:
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$ grep appletouch /var/log/Xorg.0.log
[   730.391] (II) config/udev: Adding input device appletouch (/dev/input/event5)
[   730.391] (**) appletouch: Applying InputClass "evdev touchpad catchall"
[   730.391] (**) appletouch: Applying InputClass "touchpad catchall"
[   730.392] (II) Using input driver 'synaptics' for 'appletouch'
[   730.392] (**) appletouch: always reports core events
[   730.392] (--) appletouch: x-axis range 0 - 959
[   730.392] (--) appletouch: y-axis range 0 - 644
[   730.392] (--) appletouch: pressure range 0 - 300
[   730.392] (--) appletouch: buttons: left double triple
[   730.392] (--) appletouch: invalid finger width range.  defaulting to 0 - 16
[   730.392] (--) appletouch: touchpad found
[   730.392] (**) appletouch: always reports core events
[   730.392] (II) XINPUT: Adding extended input device "appletouch" (type: TOUCHPAD, id 8)
[   730.393] (**) appletouch: (accel) MinSpeed is now constant deceleration 2.5
[   730.393] (**) appletouch: MaxSpeed is now 1.75
[   730.393] (**) appletouch: AccelFactor is now 0.173
[   730.393] (**) appletouch: (accel) keeping acceleration scheme 1
[   730.393] (**) appletouch: (accel) acceleration profile 1
[   730.393] (**) appletouch: (accel) acceleration factor: 2.000
[   730.393] (**) appletouch: (accel) acceleration threshold: 4
[   730.393] (--) appletouch: touchpad found
[   730.394] (II) config/udev: Adding input device appletouch (/dev/input/mouse1)
[   730.394] (**) appletouch: Applying InputClass "touchpad catchall"
[   730.394] (II) Using input driver 'synaptics' for 'appletouch'
[   730.394] (**) appletouch: always reports core events
[   730.394] (--) appletouch: invalid x-axis range.  defaulting to 1615 - 5685
[   730.394] (--) appletouch: invalid y-axis range.  defaulting to 1729 - 4171
[   730.394] (--) appletouch: invalid pressure range.  defaulting to 0 - 256
[   730.394] (--) appletouch: invalid finger width range.  defaulting to 0 - 16
[   730.415] (--) appletouch: no supported touchpad found
[   730.415] (EE) appletouch Unable to query/initialize Synaptics hardware.
[   730.415] (EE) PreInit returned 11 for "appletouch"
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Going to that commit's parent makes it work again, as well as reverting it on top of the 1.5.0 tag. I haven't looked at architecture-specific fun yet (endianness comes to mind), but it might be a good idea to just revert this patch for now and issue a 1.5.1 release, until we have figured this out.

I'm attaching the patch I crafted on top of 1.5.0. I will also send it to the list with an extra bugzilla reference pointing to this report.