Hi Bingbu, Wentong, On Wed, Feb 15, 2023 at 08:09:50PM +0800, Bingbu Cao wrote: > > Hi, Wentong, > > On 2/15/23 5:43 PM, Laurent Pinchart wrote: > > Hello Wentong, > > > > On Mon, Feb 13, 2023 at 10:23:44AM +0800, Wentong Wu wrote: > >> Intel Visual Sensing Controller (IVSC), codenamed "Clover Falls", is a > >> companion chip designed to provide secure and low power vision capability > >> to IA platforms. IVSC is available in existing commercial platforms from > >> multiple OEMs. > >> > >> The primary use case of IVSC is to bring in context awareness. IVSC > >> interfaces directly with the platform main camera sensor via a CSI-2 link > >> and processes the image data with the embedded AI engine. The detected > >> events are sent over I2C to ISH (Intel Sensor Hub) for additional data > >> fusion from multiple sensors. The fusion results are used to implement > >> advanced use cases like: > >> - Face detection to unlock screen > >> - Detect user presence to manage backlight setting or waking up system > > > > Do you have plan to support these features in the ivsc driver in the > > future ? > > > >> Since the Image Processing Unit(IPU) used on the host processor needs to > >> configure the CSI-2 link in normal camera usages, the CSI-2 link and > >> camera sensor can only be used in mutually-exclusive ways by host IPU and > >> IVSC. By default the IVSC owns the CSI-2 link and camera sensor. The IPU > >> driver can take ownership of the CSI-2 link and camera sensor using > >> interfaces provided by this IVSC driver. > >> > >> Switching ownership requires an interface with two different hardware > >> modules inside IVSC. The software interface to these modules is via Intel > >> MEI (The Intel Management Engine) commands. These two hardware modules > >> have two different MEI UUIDs to enumerate. These hardware modules are: > >> - ACE (Algorithm Context Engine): This module is for algorithm computing > >> when IVSC owns camera sensor. Also ACE module controls camera sensor's > >> ownership. This hardware module is used to set ownership of camera sensor. > >> - CSI (Camera Serial Interface): This module is used to route camera > >> sensor data either to IVSC or to host for IPU driver and application. > >> > >> IVSC also provides a privacy mode. When privacy mode is turned on, > >> camera sensor can't be used. This means that both ACE and host IPU can't > >> get image data. And when this mode is turned on, host IPU driver is > >> informed via a registered callback, so that user can be notified. > > > > How does the privacy mode work, and how can the user trust that the > > closed-source IVSC and IME firmwares will honour the privacy settings ? > > > > Continue with question from Laurent, > > How IVSC handle the privacy request from user? Is there some notification > mechanism to user-space? I'd have concern if IVSC driver need private callback > to request back-end(e.g. ISP driver) to handle stream cutting. How does the privacy mode work, does it just pass zeroes (or other dummy data) towards the host or nothing? A V4L2 control can be used for the purpose of passing the information to the user space at least. -- Regards, Sakari Ailus
