webcam runs when usb replugged

English Hardware
1

Hi,
I do not know where would be the best place to post this so sorry if not the correct area.
I am using opensuse x64 12.1 Linux 3.1.10-1.16-desktop x86_64
All updates in place etc.
installed a webcam to replace and old one, webcam has a built in mic .
lsusb shows Bus 002 Device 003: ID 0ac8:3450 Z-Star Microelectronics Corp.

played around a fair bit and looked at many posts on net. I want to use skype and installed this and have run it with the webcam.
If I unplug the webcam usb and replace it in same socket I get output.
After reboot webcam shows no video tried with kopete, skype and also guvcview. no output.The apps also show indicator light on webcam at this point.
from looking at other posts appears to be recognised and appears as though should be operating.
unplug usb and replace then gives output ok.
Anyone any ideas to fix?
Thanks for any replies.

2

I’m not sure why this is happening to your device from boot, but you could check to see if the simple act of removing and reinstating the webcam driver is enough to activate it again.

modprobe -r uvcvideo

modprobe uvcvideo

If so, it could be automated, so that the webcam is active when the desktop environment starts.

Does/dev/video* exist when attached from boot?

ls -l /dev/video*

Maybe the issue is implicit in the webcam’s firmware, whereby it’s state changes with no activity after a certain time period.

FWIW, although USB devices can obviously be reset by re-plugging, I found this ‘usb reset’ utility was useful to do the same (especially for remote usb devices)

How to Reset USB Device in Linux | roman10

I’ve used it to get udev to re-detect a device, by the act of resetting a particular port with a USB device that went to sleep on me.

3

Hi Deano,
Thanks for the reply.
tried the modprobe, no change
video 0 is present.
compiled and used the reset function, no change.
unplugged and put usb back to different port and runs immediately in kopete and guvcview…
Tail from messages log shows events as just the same. logs below

./reset /dev/bus/usb/001/002

Aug 6 12:34:51 MeanMachine kernel: 2155.676210] usb 1-1: USB disconnect, device number 2
Aug 6 12:34:51 MeanMachine kernel: 2155.806016] usb 1-1: new high speed USB device number 4 using ehci_hcd
Aug 6 12:34:51 MeanMachine kernel: 2155.936203] usb 1-1: New USB device found, idVendor=0ac8, idProduct=3450
Aug 6 12:34:51 MeanMachine kernel: 2155.936206] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Aug 6 12:34:51 MeanMachine kernel: 2155.936208] usb 1-1: Product: Vimicro USB Camera (Altair)
Aug 6 12:34:51 MeanMachine kernel: 2155.936209] usb 1-1: Manufacturer: Vimicro
Aug 6 12:34:51 MeanMachine kernel: 2155.937248] uvcvideo: Found UVC 1.00 device Vimicro USB Camera (Altair) (0ac8:3450)
Aug 6 12:34:51 MeanMachine kernel: 2155.938905] input: Vimicro USB Camera (Altair) as /devices/pci0000:00/0000:00:1a.7/usb1/1-1/1-1:1.0/input/input10

device not working, unplugged and replaced back in same port

Aug 6 12:34:51 MeanMachine kernel: 2155.937248] uvcvideo: Found UVC 1.00 device Vimicro USB Camera (Altair) (0ac8:3450)
Aug 6 12:34:51 MeanMachine kernel: 2155.938905] input: Vimicro USB Camera (Altair) as /devices/pci0000:00/0000:00:1a.7/usb1/1-1/1-1:1.0/input/input10
Aug 6 12:38:24 MeanMachine kernel: 2369.178027] usb 1-1: USB disconnect, device number 4
Aug 6 12:38:28 MeanMachine kernel: 2372.701020] usb 1-1: new high speed USB device number 5 using ehci_hcd
Aug 6 12:38:28 MeanMachine kernel: 2372.831258] usb 1-1: New USB device found, idVendor=0ac8, idProduct=3450
Aug 6 12:38:28 MeanMachine kernel: 2372.831260] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Aug 6 12:38:28 MeanMachine kernel: 2372.831262] usb 1-1: Product: Vimicro USB Camera (Altair)
Aug 6 12:38:28 MeanMachine kernel: 2372.831264] usb 1-1: Manufacturer: Vimicro
Aug 6 12:38:28 MeanMachine kernel: 2372.832295] uvcvideo: Found UVC 1.00 device Vimicro USB Camera (Altair) (0ac8:3450)
Aug 6 12:38:28 MeanMachine kernel: 2372.833950] input: Vimicro USB Camera (Altair) as /devices/pci0000:00/0000:00:1a.7/usb1/1-1/1-1:1.0/input/input11

first two lines here are from previous reset in log

Only thing i can notice is change from input 10 to input11, I dont know if that means anything.
Maybe the easiest answer is a new webcam , but this is frustrating as seems to be pretty much there.
I did expect the port reset to work and it does not.
I am still not certain of the problem location, could be hardware fault on the cam, but then works fine until next pwr on??

Any further suggestions welcomed, though I will not take a great deal of time and will replace the webcam if it takes too much time.
Cheers

4

I did expect the port reset to work and it does not.

So did I.

I am still not certain of the problem location, could be hardware fault on the cam, but then works fine until next pwr on??

I don’t think it is a fault as such, maybe just a quirk of the camera’s firmware (or similar), but someone else more familiar with this device may be able to chip in…