Hi Laurent, On Tue, Mar 25, 2008 at 22:58:44 +0100, Laurent Pinchart wrote:
> > I have a small suggestion for the linux-uvc driver. Currently, the > > driver lets V4L2 automatically select the device node (/dev/videoX). > > But we all know that order of loading modules, init times, et.al. may > > influence the order, therefore I thought it might by practical to > > introduce a module option to request a specific device node. [...] > This should be done using udev rules. You can then assign a device node to a > camera based on various parameters such as the device serial number, its > VID/PID or the module name. This is much more flexible than forcing a > specific minor with a module parameter. I wasn't aware that udev could do that. I'll dive into its docs (have to search first ;->). This totally obsoletes my method (albeit only for udev based systems, but are any systems without udev supported nowadays?). > The device minor can be useful, but the message in your patch can be > misleading as well. The video0 device node doesn't have to be > called /dev/video0. Some distributions name the device node /dev/v4l/video0. > The allocated device minor can easily be found using sysfs and I'm a bit > scared an incorrect /dev/videoX reference in the kernel log messages might > confuse users. Again, I wasn't aware. Correct, I only see minor. So, first observation, other kernel modules are reporting incorrectly. ;) Am I right in assuming that only the higher layers (or even udev) actually know the proper name of the assigned device node? To me, it's still a reporting problem. "Oops, where has my TV card landed? /dev/v4l/video1? Ah, there it is!" (Unfortunately, very few apps actually detect available V4L devices.) So currently, I think at least the minor number should be reported. But I'll have another think about it. Merci beaucoup, Moritz _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
