Fwd: ALPS v7 TrackStick detected wrongly

Fwd: ALPS v7 TrackStick detected wrongly

[Pali Rohár]

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Hi!

I'm Forwarding to linux-input. Looks like there can be problem with
TPPS2 protocol detection on ThinkPad laptop. Any idea?

-- 
Pali Rohár
pali.rohar@gmail.com

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From: Martin <madstitz@gmail.com>
To: pali.rohar@gmail.com
Subject: ALPS v7 TrackStick detected wrongly
Date: Thu, 14 Jan 2016 13:04:43 +0100
Message-ID: <1452773083.4165.0@smtp.gmail.com>

Hi Mr. Rohar,

I just read about your commit for kernel 4.5 ("Input: ALPS - detect 
trackstick presence for v7 protocol"),
and was wondering if this is addressing a problem I have:

I recently replaced the touchpad of my ThinkPad S440 with the one from 
the T450 (because of the dedicated trackstick buttons).
The touchpad is working fine (including the dedicated buttons), but the 
trackstick doesn't work anymore.

I suspect this is because it is detected incorrectly as an "AlpsPS/2 
ALPS DualPoint Stick" when it should be (and previously was detected 
as) an "TPPS/2 IBM TrackPoint" (checked with other S440 owner).
A friend replaced his T440 touchpad with a T450 touchpad from 
synaptics, and his trackpoint is working fine.

Relevant output of
cat /proc/bus/input/devices

I: Bus=0011 Vendor=0002 Product=0008 Version=0700
N: Name="AlpsPS/2 ALPS DualPoint Stick"
P: Phys=isa0060/serio1/input1
S: Sysfs=/devices/platform/i8042/serio1/input/input8
U: Uniq=
H: Handlers=mouse0 event6
B: PROP=21
B: EV=7
B: KEY=70000 0 0 0 0
B: REL=3

I: Bus=0011 Vendor=0002 Product=0008 Version=0700
N: Name="AlpsPS/2 ALPS DualPoint TouchPad"
P: Phys=isa0060/serio1/input0
S: Sysfs=/devices/platform/i8042/serio1/input/input5
U: Uniq=
H: Handlers=mouse1 event7
B: PROP=5
B: EV=b
B: KEY=e520 10000 0 0 0 0
B: ABS=260800000000003

I: Bus=0019 Vendor=17aa Product=5054 Version=4101
N: Name="ThinkPad Extra Buttons"
P: Phys=thinkpad_acpi/input0
S: Sysfs=/devices/platform/thinkpad_acpi/input/input9
U: Uniq=
H: Handlers=kbd event8 rfkill
B: PROP=0
B: EV=13
B: KEY=10040 0 18040000 0 10000000000000 0 1501b02102004 
c000280041114000 10e000000000000 0
B: MSC=10


Is your patch intended to solve this or should I open a bug ticket?

Thank you very much for your time!

Greetings
Martin Stitz

Re: ALPS v7 TrackStick detected wrongly

[Dmitry Torokhov]

On Thu, Jan 14, 2016 at 4:11 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> Hi!
>
> I'm Forwarding to linux-input. Looks like there can be problem with
> TPPS2 protocol detection on ThinkPad laptop. Any idea?

Replacing Synaptics for ALPS touchpad and expect trackpoint to
continue to work as it was is not realistic. The only way we properly
identify trackpoint if it is connected directly to the AUX port or if
it is connected to Synaptics pass-though port. In case of ALPS it
"merges" into touchpad (and we spend considerate effort untangling the
trackpoint data from touchpad data), so we handle trackpoint data, bit
never show it as TPPS/2.

That said I am confused how you ended up with ALPS as I believe
ThinkPads use only Synaptics.

Thanks.

>
> --
> Pali Rohár
> pali.rohar@gmail.com
>
>
> ---------- Forwarded message ----------
> From: Martin <madstitz@gmail.com>
> To: pali.rohar@gmail.com
> Cc:
> Date: Thu, 14 Jan 2016 13:04:43 +0100
> Subject: ALPS v7 TrackStick detected wrongly
> Hi Mr. Rohar,
>
> I just read about your commit for kernel 4.5 ("Input: ALPS - detect trackstick presence for v7 protocol"),
> and was wondering if this is addressing a problem I have:
>
> I recently replaced the touchpad of my ThinkPad S440 with the one from the T450 (because of the dedicated trackstick buttons).
> The touchpad is working fine (including the dedicated buttons), but the trackstick doesn't work anymore.
>
> I suspect this is because it is detected incorrectly as an "AlpsPS/2 ALPS DualPoint Stick" when it should be (and previously was detected as) an "TPPS/2 IBM TrackPoint" (checked with other S440 owner).
> A friend replaced his T440 touchpad with a T450 touchpad from synaptics, and his trackpoint is working fine.
>
> Relevant output of
> cat /proc/bus/input/devices
>
> I: Bus=0011 Vendor=0002 Product=0008 Version=0700
> N: Name="AlpsPS/2 ALPS DualPoint Stick"
> P: Phys=isa0060/serio1/input1
> S: Sysfs=/devices/platform/i8042/serio1/input/input8
> U: Uniq=
> H: Handlers=mouse0 event6
> B: PROP=21
> B: EV=7
> B: KEY=70000 0 0 0 0
> B: REL=3
>
> I: Bus=0011 Vendor=0002 Product=0008 Version=0700
> N: Name="AlpsPS/2 ALPS DualPoint TouchPad"
> P: Phys=isa0060/serio1/input0
> S: Sysfs=/devices/platform/i8042/serio1/input/input5
> U: Uniq=
> H: Handlers=mouse1 event7
> B: PROP=5
> B: EV=b
> B: KEY=e520 10000 0 0 0 0
> B: ABS=260800000000003
>
> I: Bus=0019 Vendor=17aa Product=5054 Version=4101
> N: Name="ThinkPad Extra Buttons"
> P: Phys=thinkpad_acpi/input0
> S: Sysfs=/devices/platform/thinkpad_acpi/input/input9
> U: Uniq=
> H: Handlers=kbd event8 rfkill
> B: PROP=0
> B: EV=13
> B: KEY=10040 0 18040000 0 10000000000000 0 1501b02102004 c000280041114000 10e000000000000 0
> B: MSC=10
>
>
> Is your patch intended to solve this or should I open a bug ticket?
>
> Thank you very much for your time!
>
> Greetings
> Martin Stitz
>
>

-- 
Dmitry
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Re: Fwd: ALPS v7 TrackStick detected wrongly

[Pali Rohár]

On Thursday 14 January 2016 13:04:43 Martin <madstitz@gmail.com> wrote:
> Is your patch intended to solve this or should I open a bug ticket?

Hi! That my patch hides Track Stick input device when ALPS touchpad
report that Track Stick is not present. Before my patch was applied
kernel created "AlpsPS/2 ALPS DualPoint Stick" input device for V7
protocol always, even if there was no Track Stick device.

But as Dmitry said, you replaced Synaptics touchpad with ALPS which is
working differently. Synaptics touchpad export PS/2 bus via its own
pass-though protocol and this bus then available on kernel which do
normal PS/2 mouse detection it. So kernel bind thinkpad TPPS2 driver to
that bus.

ALPS is working differently. There is no pass-though mode and all data
(touchpad, track stick) are exported in ALPS packets. Kernel ALPS driver
has special parser which can decide if packet comes from touchpad or
trackstick (based on received data). So via ALPS touchpad kernel cannot
communicate directly with trackpoint.

So I guess... in case you have thinkpad trackpoint HW and ALPS touchpad
which cannot work with that trackpoint you just do not get trackpoint
data. Here kernel cannot do anything.

I suspect that if you apply my patch (which check presence of
trackstick) then kernel probably do not export this track stick device
"AlpsPS/2 ALPS DualPoint Stick" anymore...

> I: Bus=0011 Vendor=0002 Product=0008 Version=0700
> N: Name="AlpsPS/2 ALPS DualPoint Stick"
> P: Phys=isa0060/serio1/input1
> S: Sysfs=/devices/platform/i8042/serio1/input/input8
> U: Uniq=
> H: Handlers=mouse0 event6
> B: PROP=21
> B: EV=7
> B: KEY=70000 0 0 0 0
> B: REL=3

-- 
Pali Rohár
pali.rohar@gmail.com
--
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Re: Fwd: ALPS v7 TrackStick detected wrongly

[Martin]

So I can't be sure if it even detects the trackstick, because it just 
creates the device anyway?

I bought the trackpad from eBay, as Lenovo doesn't sell it separately.
Apparently its pure luck if you get a Synaptics or Alps model - I got 
the Alps, my friend got the Synaptics model.
Don't know whether Lenovo uses Alps in its newer series too or if this 
trackpad is a fake (feels and works very real though ;))

Maybe I'll try to get a synaptics then, as this was the manufacturer of 
the original trackpad.

Greetings
Martin


Am Do, 14. Jan, 2016 um 9:07 schrieb Pali Rohár <pali.rohar@gmail.com>:
> On Thursday 14 January 2016 13:04:43 Martin <madstitz@gmail.com> 
> wrote:
>>  Is your patch intended to solve this or should I open a bug ticket?
> 
> Hi! That my patch hides Track Stick input device when ALPS touchpad
> report that Track Stick is not present. Before my patch was applied
> kernel created "AlpsPS/2 ALPS DualPoint Stick" input device for V7
> protocol always, even if there was no Track Stick device.
> 
> But as Dmitry said, you replaced Synaptics touchpad with ALPS which is
> working differently. Synaptics touchpad export PS/2 bus via its own
> pass-though protocol and this bus then available on kernel which do
> normal PS/2 mouse detection it. So kernel bind thinkpad TPPS2 driver 
> to
> that bus.
> 
> ALPS is working differently. There is no pass-though mode and all data
> (touchpad, track stick) are exported in ALPS packets. Kernel ALPS 
> driver
> has special parser which can decide if packet comes from touchpad or
> trackstick (based on received data). So via ALPS touchpad kernel 
> cannot
> communicate directly with trackpoint.
> 
> So I guess... in case you have thinkpad trackpoint HW and ALPS 
> touchpad
> which cannot work with that trackpoint you just do not get trackpoint
> data. Here kernel cannot do anything.
> 
> I suspect that if you apply my patch (which check presence of
> trackstick) then kernel probably do not export this track stick device
> "AlpsPS/2 ALPS DualPoint Stick" anymore...
> 
>>  I: Bus=0011 Vendor=0002 Product=0008 Version=0700
>>  N: Name="AlpsPS/2 ALPS DualPoint Stick"
>>  P: Phys=isa0060/serio1/input1
>>  S: Sysfs=/devices/platform/i8042/serio1/input/input8
>>  U: Uniq=
>>  H: Handlers=mouse0 event6
>>  B: PROP=21
>>  B: EV=7
>>  B: KEY=70000 0 0 0 0
>>  B: REL=3
> 
> --
> Pali Rohár
> pali.rohar@gmail.com

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Re: Fwd: ALPS v7 TrackStick detected wrongly

[Pali Rohár]

On Friday 15 January 2016 12:27:16 Martin wrote:
> So I can't be sure if it even detects the trackstick, because it just
> creates the device anyway?

Yes, this is how alps driver for v7 protocol worked before my patch.

-- 
Pali Rohár
pali.rohar@gmail.com
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Re: ALPS v7 TrackStick detected wrongly

[Pali Rohár]

On Thursday 14 January 2016 11:34:30 Dmitry Torokhov wrote:
> That said I am confused how you ended up with ALPS as I believe
> ThinkPads use only Synaptics.

Looks like this is not truth. At least Lenovo has drivers for ALPS
touchpads for selected ThinkPad models. See:
http://support.lenovo.com/us/en/downloads/ds101942

-- 
Pali Rohár
pali.rohar@gmail.com
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