Re: [PATCH] input: ALPS - Add signature for HP Pavilion dm3 laptops

[Chase Douglas <chase.douglas@canonical.com>]

On Tue, Apr 20, 2010 at 9:01 AM, Chase Douglas
<chase.douglas@canonical.com> wrote:
> On Tue, Apr 20, 2010 at 12:29 AM, Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
>> On Mon, Apr 19, 2010 at 01:36:33PM -0700, Chase Douglas wrote:
>>> After more testing, some users found that they no longer could use the
>>> vertical edge scroll of their touchpad. I assumed everything was
>>> working correctly because I had read a response to another user on
>>> this list that if you add a new ID, things work, and you don't see any
>>> protocol error messages in dmesg, then things should be correct. The
>>> testers reported no errors, so I assumed the problem was in the X
>>> synaptics driver. However, after receiving some event reports from a
>>> tester, it may be that the normal ps2 driver is still sending events,
>>> while the alps/synaptics kernel driver is not sending any. Do you have
>>> any insight on what might be going on?
>>>
>>
>> That means that our standard magic knock did not work. It seems that
>> newer version of ALPS are using a different "magic knock" sequence for
>> them.
>
> How can we find out what the new knock sequence is?

I've had more testing done by others with hardware. It's clear to me
that the magic knock sequence in alps.c does not work for this device.
I have tried both with ALPS_PASS as well, with no change. That means
that we have two potential ways to go from here:

a. Revert the signature and use the ImPS/2 Generic Wheel Mouse driver,
which provides wheel events automatically but without any absolute
event support
b. Leave the signature as is, which disables wheel events and enables
no extra functionality

I would call b a regression. Maybe we can figure out the new knock
protocol before the change propagates from tip to distros, but I think
it's better to revert the signature and reapply it later when we find
the right sequence. What do you think?

-- Chase