On Wed, 14 Jan 2009, Mike Isely wrote: > On Wed, 14 Jan 2009, Mauro Carvalho Chehab wrote: > > [...] > > > > > I can see some troubles here: > > > > 1) The bus info helps to identify the place where you'll find the > > device info at sysfs; > > > > 2) This is a V4L2 API non-compliance. All drivers should be compliant > > with the API; > > > > 3) If we all agree that bus_info doesn't matter at all and decide to > > change V4L2 API, we'll still have a big trouble: most devices don't > > have a serial number. > > > > The other patches are ok. > > I was asked to make this change, because otherwise there's no means via > the V4L interface to uniquely REPEATABLY be able to identify the same > device each time it is plugged in. I have gotten complaints about this. > I actually pointed out that bus_info was about the "where" not the > "what" of the device, but I was convinced to change this - after being > surprised that the V4L spec allowed for this. Look at the online v4l > spec; the following description exists about bus_info (as part of the > VIDIOC_QUERYCAP description): > [...] Mauro: If you still don't like this specific changeset, then OK, but I'd still appreciate it if you could pull the other changes (especially the v4l2_subdev fix). And I'd appreciate some suggestions from anyone about a means via the V4L interface to make available a device-specific identifier, like a serial number. Yes I know such a thing is not always available with all devices, but it is available for Hauppauge devices in general and users want to have access to that information for purposes of mapping behavior in userspace. -Mike -- Mike Isely isely @ pobox (dot) com PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
