While searching on this issue, I came across an Ubuntu bug report from late Feb this year (<a href="https://bugs.launchpad.net/ubuntu/+source/hal/+bug/196811" target="_blank">https://bugs.launchpad.net/ubuntu/+source/hal/+bug/196811</a>), where someone reports pretty much the same thing as me (a logitech quickcam not being reported as a v4l device by HAL). A bug report was also created on fd.o (<a href="https://bugs.freedesktop.org/show_bug.cgi?id=14809">https://bugs.freedesktop.org/show_bug.cgi?id=14809</a>), but it then was marked as resolved & fixed even though it still doesnt work with hal-0.5.11 (I can provide a trace if required). Any comments ? Cheers, Gilles PS: I have checked out a copy of HAL with git and I m happy to try it if someone tells me how to compile it. <div class="gmail_quote">On Wed, May 28, 2008 at 12:09 PM, Gilles GIGAN <<a href="mailto:gilles.gigan@gmail.com" target="_blank">gilles.gigan@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Further to my previous post, I ran udevmonitor and plugged in both webcams in turns. For the Creative NX webcam, udev sends: UEVENT[1211938254.674635] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2 (usb) UDEV  [1211938254.679570] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2 (usb) UEVENT[1211938254.679599] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/5-2:1.0 (usb) UDEV  [1211938254.693902] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/usb_endpoint/usbdev5.8_ep00 (usb_endpoint) UDEV  [1211938254.776316] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/5-2:1.0 (usb) UEVENT[1211938254.866628] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/5-2:1.0/usb_endpoint/usbdev5.8_ep81 (usb_endpoint) UEVENT[1211938254.866660] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/5-2:1.0/usb_endpoint/usbdev5.8_ep82 (usb_endpoint) UEVENT[1211938254.866742] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/video4linux/video1 (video4linux) UDEV  [1211938254.873827] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/5-2:1.0/usb_endpoint/usbdev5.8_ep81 (usb_endpoint) UDEV  [1211938254.875099] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/5-2:1.0/usb_endpoint/usbdev5.8_ep82 (usb_endpoint) UDEV  [1211938254.876226] add      /devices/pci0000:00/0000:00:1d.2/usb5/5-2/video4linux/video1 (video4linux) (this is the one where a video4linux HAL object is created) for the Logitech Quickcam: UEVENT[1211938261.097625] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1 (usb) UEVENT[1211938261.098128] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/usb_endpoint/usbdev1.5_ep00 (usb_endpoint) UDEV  [1211938261.099268] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1 (usb) UDEV  [1211938261.100519] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/usb_endpoint/usbdev1.5_ep00 (usb_endpoint) UEVENT[1211938261.100614] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0 (usb) UEVENT[1211938261.102634] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0/usb_endpoint/usbdev1.5_ep81 (usb_endpoint) UEVENT[1211938261.102702] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0/usb_endpoint/usbdev1.5_ep82 (usb_endpoint) UEVENT[1211938261.108634] add      /devices/virtual/video4linux/video2 (video4linux) UDEV  [1211938261.110296] add      /devices/virtual/video4linux/video2 (video4linux) UDEV  [1211938261.151902] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0 (usb) UDEV  [1211938261.153254] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0/usb_endpoint/usbdev1.5_ep81 (usb_endpoint) UDEV  [1211938261.154323] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1:1.0/usb_endpoint/usbdev1.5_ep82 (usb_endpoint) (for this webcam, no video4linux HAL object is created) In the first instance the video4linux device is a child kobject of the USB connection kobject. Whereas in the second case, the video4linux kobject ends up in /devices/virtual instead, which is the location for devices that dont have a real parent kobject (AFAIK). I suspect this is why the HAL video4linux object is not created in the second case. Can someone confirm ? Checking the contents of /sys/devices/virtual shows a lot of kobjects, including some that are properly reported by HAL. On my computer, ' lshal | grep "/virtual" ' shows event-input objects and ALSA objects (sequencer, timer), all with "linux.sysfs_path" pointing somewhere in /sys/devices/virtual and linux.device_file pointing to a device file in /dev Which brings me back to that question: why isnt the Quickcam also detected and reported ? cheers, Gilles<div><div></div><div> <div class="gmail_quote">On Mon, May 26, 2008 at 9:49 AM, Gilles GIGAN <<a href="mailto:gilles.gigan@gmail.com" target="_blank">gilles.gigan@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi all, When I connect a USB webcam, org.freedesktop.Hal.Manager generates a couple of DeviceAdded signals for the newly created HAL objects. One of these objects usually has the 'Video4Linux' capability. These are the HAL objects created when I plug in a Creative NX webcam (no microphone): /org/freedesktop/Hal/devices/usb_device_41e_401c_noserial /org/freedesktop/Hal/devices/usb_device_ffffffff_ffffffff_noserial /org/freedesktop/Hal/devices/usb_device_41e_401c_noserial_video4linux The last one in this case holds the information about V4L and is easily identifiable by checking at least "info.category" and "info.capabilities". However, when I connect an old Logitech Quickcam express (qc-usb driver), no V4L-related object is created and I only get:. /org/freedesktop/Hal/devices/usb_device_46d_840_noserial /org/freedesktop/Hal/devices/usb_device_46d_840_noserial_if0 grep'ping syslog shows the webcam has been detected and the device file created. Is this HAL-related or driver-related ? If it is driver-related, which step (specifically which function call) usually notifies HAL that a new V4L object has been added ? is it tied to one of the sysfs routines ? Thanks, Gilles </blockquote></div> </div></div></blockquote></div>