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jocom

Member

Registered: 2009-04-29

Posts: 74

Touchpad responds, but isn't listed in lspci => no X

Hi,

Does anybody know why

lspci

doesn't list my touchpad (Synaptic) while

cat /dev/input/mice

does produce output when I stroke my touchpad?

Due to this I can't get xf86-input-synaptic working.

If you need more pointers for solving this problem, please ask for them.

jocom

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,349

Re: Touchpad responds, but isn't listed in lspci => no X

The touchpad is not a PCI device.  They are usually a PS/2 type serial device and talk to the (I Think) Southbridge chip on pins dedicated to PS/2 devices (like serial keyboards and mice).  The kernel drivers are usually serial UART drivers.

Take a look in /proc/bus/input/devices for the info I think you seek.

Last edited by ewaller (2010-11-27 05:31:51)

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ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,349

Re: Touchpad responds, but isn't listed in lspci => no X

Continuing (after some further thought).  Actually, (for Intel chip sets)the serial devices probably connect to the Southbridge through a bus called the LPC (Low Pin Count).  This bus is used to connect things that are relatively slow that, in antiquity, would have lived on an ISA or EISA bus.  "Traditional" I/O addresses such as 0x380-0x38f or 0x280-0x28f (COM1 and COM2 in PC-Compatibles) are mapped down to the LPC.  There are interface chips that implement the LPC on one side and the PS/2 serial ports, IBM-PC Parallel ports, etc.  on the other side.  The touchpad probably connects to one of the LPC client chips, which talks up through the Southbridge.

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Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

jocom

Member

Registered: 2009-04-29

Posts: 74

Re: Touchpad responds, but isn't listed in lspci => no X

Ok, thanks a lot for your reply.
The touchpad is indeed listed in /dev/bus/input/devices.

But, then my following question arises: Why does X complain that it cannot find a Synaptic touchpad when I fire it up?

I installed xorg-input-synaptics ...

jocom

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,349

Re: Touchpad responds, but isn't listed in lspci => no X

Did you also load xf86-input-evdev ?? (Sorry, I know it is a basic question.)
Does your keyboard work ?
Does the touch pad work behave like an emualated mouse?

Can you post the portion of the /var/log/Xorg.0.log in which X complains about the touch pad?

Thanks.

---

Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

jocom

Member

Registered: 2009-04-29

Posts: 74

Re: Touchpad responds, but isn't listed in lspci => no X

Hi,

I decided to reinstall the whole X part.
But when I now run pacman -S xorg
I get error (conflicting files), certain files still exist on my filesystem.
How do I fix this?

jocom