a16f6497_Linux_UVC_driver___tools___FAQ__Description
[Name] UVC_QUIRK_IGNORE_SELECTOR_UNIT [Value] 0x00000020 [Description] 
Ignore UVC selector units. Selector units allow selecting the active input for multi-input video devices. Many webcams expose a selector unit with a single input, which is pointless by valid nonetheless. However, at least one camera exposes a selector unit but doesn't implement associated requests. The selector unit then has to be ingored. Try to set this quirk if VIDIOC_G_INPUT fail.
Linux UVC driver & tools – FAQ
Description