Hi Ricardo, On Wed, Oct 30, 2024 at 02:03:18PM +0100, Ricardo Ribalda wrote: > Hi Hans (de Goede, but others are welcome as well :) ) > > Some notebooks have a button to disable the camera (not to be mistaken > with the mechanical cover). This is a standard GPIO linked to the > camera via the ACPI table. > > 4 years ago we added support for this button in UVC via the Privacy control. > This has two issues: > - If the camera has its own privacy control, it will be masked > - We need to power-up the camera to read the privacy control gpio. > > We tried to fix the power-up issues implementing "granular power > saving" but it has been more complicated than anticipated.... > > Last year, we proposed a patchset to implement the privacy gpio as a > subdevice https://lore.kernel.org/linux-media/20230111-uvc_privacy_subdev-v1-0-f859ac9a01e3@xxxxxxxxxxxx/ > > I think it is a pretty clean solution and makes sense to use a > subdevice for something that is a sub device of the camera :). > > Before moving forward, Laurent and I would like to hear your opinion. I remember we discussed this and I wasn't very enthusiastic about the proposal but thinking about it again, there are situations where this is the only feasible solution, including on raw cameras with a privacy GPIO, besides the first issue you brought up above. Regarding the second one, why would you need to power on the camera to get the GPIO's value? I'll review the set. While in the case of UVC it's fairly clear what the sub-device is related to, but for the general case it'd be good to have an ancillary link there. -- Regards, Sakari Ailus
