I've got more of a basic question for you:
My linux kernel (I tried several here from stock 2.6, 3.2 and 3.5 as well as a custom 3.7.3 one) does not detect my synaptics touchpad - or I'am too dumb to find it. I looked into: dmesg, lsusb -v, lspci -v, lshw, /dev/input, /dev/bus/00x/ (...)
It shows me several internal usb root hubs and integrated rate matching hubs, my pendrive and optical mouse but nothing else of interest.
Now, as for the question: is it possible that the kernel does not detect certain hardware if there is no driver available? As far as I understand it, the kernel should at least report some unknown device at some hardware address.
Thanks for your time.
dmesg | grep input
[ 3.529623] input: Sleep Button as /devices/LNXSYSTM:00/device:00/PNP0C0E:00/input/input0
[ 3.529659] input: Power Button as /devices/LNXSYSTM:00/device:00/PNP0C0C:00/input/input1
[ 3.529694] input: Lid Switch as /devices/LNXSYSTM:00/device:00/PNP0C0D:00/input/input2
[ 3.529745] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input3
[ 5.196578] input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input4
[ 5.847405] input: Logitech USB-PS/2 Optical Mouse as /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.3/1-1.3:1.0/input/input5
[ 5.847752] hid-generic 0003:046D:C050.0001: >input,hidraw0: USB HID v1.10 Mouse [Logitech USB-PS/2 Optical Mouse] on usb-0000:00:1a.0-1.3/input0
[ 5.993994] input: Video Bus as /devices/LNXSYSTM:00/device:00/PNP0A08:00/LNXVIDEO:00/input/input6
[ 15.474899] input: HDA Intel PCH HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input7
[ 15.475781] input: HDA Intel PCH Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input8
[ 15.475950] input: HDA Intel PCH Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input9
cat /proc/bus/input/devices
I: Bus=0019 Vendor=0000 Product=0003 Version=0000
N: Name="Sleep Button"
P: Phys=PNP0C0E/button/input0
S: Sysfs=/devices/LNXSYSTM:00/device:00/PNP0C0E:00/input/input0
U: Uniq=
H: Handlers=kbd event0
B: PROP=0
B: EV=3
B: KEY=4000 0 0
I: Bus=0019 Vendor=0000 Product=0001 Version=0000
N: Name="Power Button"
P: Phys=PNP0C0C/button/input0
S: Sysfs=/devices/LNXSYSTM:00/device:00/PNP0C0C:00/input/input1
U: Uniq=
H: Handlers=kbd event1
B: PROP=0
B: EV=3
B: KEY=10000000000000 0
I: Bus=0019 Vendor=0000 Product=0005 Version=0000
N: Name="Lid Switch"
P: Phys=PNP0C0D/button/input0
S: Sysfs=/devices/LNXSYSTM:00/device:00/PNP0C0D:00/input/input2
U: Uniq=
H: Handlers=event2
B: PROP=0
B: EV=21
B: SW=1
I: Bus=0019 Vendor=0000 Product=0001 Version=0000
N: Name="Power Button"
P: Phys=LNXPWRBN/button/input0
S: Sysfs=/devices/LNXSYSTM:00/LNXPWRBN:00/input/input3
U: Uniq=
H: Handlers=kbd event3
B: PROP=0
B: EV=3
B: KEY=10000000000000 0
I: Bus=0011 Vendor=0001 Product=0001 Version=ab83
N: Name="AT Translated Set 2 keyboard"
P: Phys=isa0060/serio0/input0
S: Sysfs=/devices/platform/i8042/serio0/input/input4
U: Uniq=
H: Handlers=sysrq kbd event4
B: PROP=0
B: EV=120013
B: KEY=402000000 3803078f800d001 feffffdfffefffff fffffffffffffffe
B: MSC=10
B: LED=7
I: Bus=0019 Vendor=0000 Product=0006 Version=0000
N: Name="Video Bus"
P: Phys=LNXVIDEO/video/input0
S: Sysfs=/devices/LNXSYSTM:00/device:00/PNP0A08:00/LNXVIDEO:00/input/input6
U: Uniq=
H: Handlers=kbd event6
B: PROP=0
B: EV=3
B: KEY=3e000b00000000 0 0 0
I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="HDA Intel PCH HDMI/DP,pcm=3"
P: Phys=ALSA
S: Sysfs=/devices/pci0000:00/0000:00:1b.0/sound/card0/input7
U: Uniq=
H: Handlers=event7
B: PROP=0
B: EV=21
B: SW=140
I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="HDA Intel PCH Mic"
P: Phys=ALSA
S: Sysfs=/devices/pci0000:00/0000:00:1b.0/sound/card0/input8
U: Uniq=
H: Handlers=event8
B: PROP=0
B: EV=21
B: SW=10
I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="HDA Intel PCH Headphone"
P: Phys=ALSA
S: Sysfs=/devices/pci0000:00/0000:00:1b.0/sound/card0/input9
U: Uniq=
H: Handlers=event9
B: PROP=0
B: EV=21
B: SW=4
I: Bus=0003 Vendor=046d Product=c050 Version=0110
N: Name="Logitech USB-PS/2 Optical Mouse"
P: Phys=usb-0000:00:14.0-3/input0
S: Sysfs=/devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/input/input11
U: Uniq=
H: Handlers=mouse0 event5
B: PROP=0
B: EV=17
B: KEY=ff0000 0 0 0 0
B: REL=143
B: MSC=10
lsusb
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 003 Device 002: ID 0951:1642 Kingston Technology DT101 G2
Bus 003 Device 004: ID 046d:c050 Logitech, Inc. RX 250 Optical Mouse
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub