Re: Big ptoblem with small webcam

["W.P." <laurentp@wp.pl>]

Użytkownik Laurent Pinchart napisał:
> Hi,
>
> On Wednesday 02 March 2011 16:57:05 W.P. wrote:
>   
>> Hi there,
>> I just got an Creative VGA (640x480) USB Live Webcam, VF0520.
>>
>> lsusb (partial):
>>
>> Bus 003 Device 007: ID 041e:406c Creative Technology, Ltd
>> Device Descriptor:
>>   bLength                18
>>   bDescriptorType         1
>>   bcdUSB               2.00
>>   bDeviceClass          239 Miscellaneous Device
>>   bDeviceSubClass         2 ?
>>   bDeviceProtocol         1 Interface Association
>>   bMaxPacketSize0        64
>>   idVendor           0x041e Creative Technology, Ltd
>>   idProduct          0x406c
>>   bcdDevice           10.19
>>   iManufacturer           1 Creative Labs
>>   iProduct                3 VF0520 Live! Cam Sync
>>   iSerial                 0
>>   bNumConfigurations      1
>>
>> lsmod | grep vid:
>> uvcvideo               50184  0
>> compat_ioctl32          5120  1 uvcvideo
>> videodev               32000  1 uvcvideo
>> v4l1_compat            15876  2 uvcvideo,videodev
>>
>> uname -a (kernel from Fedora 10):
>> [root@laurent-home ~]# uname -a
>> Linux laurent-home 2.6.27.5-117.fc10.i686 #1 SMP Tue Nov 18 12:19:59 EST
>> 2008 i686 athlon i386 GNU/Linux
>>
>> Problem: device nodes are created, but NO video in gmplayer, tvtime
>> complains: can't open /dev/video0.
>>
>> Only trace in syslog is:
>>
>> Mar  2 16:26:56 laurent-home kernel: uvcvideo: Failed to submit URB 0
>> (-28).
>>     
>
> This means the webcam requires more USB bandwidth than available. Another 
> device probably uses USB bandwidth (it could be another webcam, an audio 
> device, ...).
>
>   
It is the only USB 2.0 device connected (rest are keyboard, mouse, 2x
PL2303 converters, BT, and WiFi (unused). But what is strange: it seems
device runs in 1.1 mode:

Mar  3 15:54:46 laurent-home kernel: usb 3-1.4: new full speed USB
device using
 uhci_hcd and address 24
Mar  3 15:54:47 laurent-home kernel: usb 3-1.4: *not running at top
speed*; conne
ct to a high speed hub
Mar  3 15:54:47 laurent-home kernel: usb 3-1.4: configuration #1 chosen
from 1
choice
Mar  3 15:54:47 laurent-home kernel: uvcvideo: Found UVC 1.00 device
VF0520 Liv
e! Cam Sync (041e:406c)
Mar  3 15:54:47 laurent-home kernel: uvcvideo: Found a valid video chain
(1 ->
2).
Mar  3 15:54:47 laurent-home kernel: input: VF0520 Live! Cam Sync as
/devices/p
ci0000:00/0000:00:0b.1/usb3/3-1/3-1.4/3-1.4:1.0/input/input19
Mar  3 15:54:47 laurent-home kernel: usb 3-1.4: New USB device found,
idVendor=
041e, idProduct=406c
Mar  3 15:54:47 laurent-home kernel: usb 3-1.4: New USB device strings:
Mfr=1,
Product=3, SerialNumber=0
Mar  3 15:54:47 laurent-home kernel: usb 3-1.4: Product: VF0520 Live!
Cam Sync
Mar  3 15:54:47 laurent-home kernel: usb 3-1.4: Manufacturer: Creative Labs

But I have tested it with 2 hubs on different controller ports, same.
>> Webcam is connected to VIA USB 2.0 controller through a USB 2.0 hub.
>>
>> What is strange, two days ago I tried apparently the same (model VFxxxx)
>> with SUCCESS.
>> Device seems working in Windoze (Ekiga).
>>
>> What should I check/ do?
>>     
Only switching OS (for test) and it works. WTF?

W.P.