camera (device class)¶
USB cameras, including a laptop's built-in webcam — parked when nobody is using them
A camera on USB, which in practice means a UVC webcam: the laptop's built-in one, or one plugged in. The kernel drives it with uvcvideo and presents it as /dev/videoN.
Devices in this class¶
Shared setup¶
Nothing to install. Park and wake are hammunition hardware park camera and hammunition hardware wake camera, through the same helper the tray uses.
Power control¶
This device can be parked and woken. Method: usb_deauthorize.
A parked USB camera is unconfigured, not unpowered at the port: uvcvideo drops /dev/videoN and the port is only allowed to suspend, so the camera stops being a camera to every program. This does not cut its supply, and it is not a hardware privacy switch: a camera is as unusable while parked as software can make it, which is a statement about the kernel's view, not a guarantee about the module. Nothing needs quieting first. Parking has not been run on a camera here (unmeasured).
See device power control for what parking does to a machine, how to inspect it and how to reverse it.