Bug#703715: Kernel bug ALPS TouchPad and i915 DRM do not play nicely on Wheezy 3.2.0-4-amd64

[Darren Williams <Darren.Williams@nicta.com.au>]

Hi Guys

I have been tracking this bug since installing Wheezy a few weeks ago.

After a weekend of testing I discovered that this bug is related to the
ALPS DualPoint TouchPad device and the DRM i915 modules. More precisely
the scroll bar on the touch pad.

testing I have:

1. Built and run the earliest stable branch where the synaptic_usb code
was introduced, v3.4.0.
   I could not reproduce the bug.

2. stable tree 3.3.0  with patches
   features/all/Input-add-Synaptics-USB-device-driver.patch
   features/all/USB-add-USB_VENDOR_AND_INTERFACE_INFO-macro.patch

   I could not reproduce the bug

   Turned out I was chasing the wrong device though on the right path.

3. Tested 3.2.46 and 3.2.47 from the stable tree with with patches
   features/all/Input-ALPS-move-protocol-information-to-Documentatio.patch
   features/all/Input-ALPS-add-protocol-version-field-in-alps_model_.patch
   features/all/Input-ALPS-remove-assumptions-about-packet-size.patch
   features/all/Input-ALPS-add-support-for-protocol-versions-3-and-4.patch
   features/all/Input-ALPS-add-semi-MT-support-for-v3-protocol.patch
   features/all/Input-add-Synaptics-USB-device-driver.patch
   features/all/USB-add-USB_VENDOR_AND_INTERFACE_INFO-macro.patch

   Bug reproducible

4. Tested 3.2.48 from stable tree with patches
   features/all/Input-add-Synaptics-USB-device-driver.patch
   features/all/USB-add-USB_VENDOR_AND_INTERFACE_INFO-macro.patch

   I could not reproduce the bug

5. Possible fix candidate: e24fb4d67f53530038a9711d0c1f65937490bb8c

I'm no kernel expert and testing this bug is difficult, in some cases it
turns up as soon as you start Libre Office and start scrolling with the
touch pad, in others it may take 20 - 30 mins.

I'll run with patched 3.2.48 for a week and let you know the results

Details of my machine:
System Information
        Manufacturer: Dell Inc.
        Product Name: Latitude E6220
        Product Name: 0R97MN
        Version: A00
        CPU: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz
        Mouse: AlpsPS/2 ALPS DualPoint TouchPad
        VGA compatible controller: Intel Corporation 2nd Generation
Core Processor Family Integrated Graphics Controller (rev 09)

Hope this helps
Darren

--

Darren Williams
National ICT Australia Limited
Web: http://www.nicta.com.au
The imagination driving Australia's ICT future.

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