Re: Regression since commit 92bac83

[Dmitry Torokhov]

On Mon, Oct 19, 2015 at 10:55:20AM -0500, Larry Finger wrote:
> On 10/19/2015 03:08 AM, Hans de Goede wrote:
> >Hi,
> >
> >On 19-10-15 01:59, Larry Finger wrote:
> >>Hi,
> >>
> >>I recently upgraded the kernel in a Dell Latitude D600 and found that the
> >>touchpad clicks failed. The problem was bisected to commit
> >>92bac83dd79e60e65c475222e41a992a70434beb ("Input: alps - non interleaved V2
> >>dualpoint has separate stick button bits"). The laptop has a combination
> >>touchpad and control stick. For this device, the following values are found:
> >>
> >>priv->protoversion is 0x200 (ALPS_PROTO_V2)
> >>priv->flags is 0x6 (ALPS_DUALPOINT | ALPS_PASS)
> >>
> >>As a result, the new code added in this patch is executed, and left, right,
> >>and middle are updated. Once this code is introduced, a left click causes some
> >>event as it will wake a sleeping screen, but not select any windows or do
> >>anything useful.
> >>
> >>Please advise on what information would be needed to help debug this problem.
> >
> >Can you build a recent upstream kernel from source, and when building it
> >comment out these lines in drivers/input/mouse/alps.c, around lines 2555 - 2556
> >
> >         if (dmi_name_in_vendors("Dell"))
> >                 priv->flags |= ALPS_DELL;
> >
> >That should fix things, if that fixes things we need to rename the flag
> >and move to a list of dmi-matched models (rather then vendor) where the new
> >behavior
> >introduced by the patch causing you problems is actually necessary.
> >
> >Step 1 is confirming that not setting the flag fixes things for you,
> >if you can get back to us confirming that, then I'll whip up a patch
> >to switch to model matching (which is not ideal, but seems to be
> >necessary).
> 
> Thanks for the quick response. Removing the two lines mentioned
> above restored correct touchpad operation with kernel 4.2.0. It
> seems that the Latitude D600 is different than other Dell models.

I wonder if we should not revert all these patches splitting what once
was one relative input device into separate trackstick/external mouse.
They seem to cause a lot of troubles for little benefit. Pali?

Thanks.

-- 
Dmitry
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