> -----Original Message----- > From: Bingbu Cao <bingbu.cao@xxxxxxxxxxxxxxx> > Sent: Friday, February 17, 2023 9:44 AM > > Hi, Sakari, > > On 2/16/23 9:12 PM, Sakari Ailus wrote: > > 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 ? > > As I know, without IVSC, once user enable the privacy mode, the Intel > Converged Security Engine will configure the IPU camera mask (security register), > which will mask the specific CSI2 port and produce dummy imaging data. For the > case with IVSC, there is no final solution on Linux so far I think. > > Wentong, is IVSC trying to cut off the stream and then notify user and IPU? yes > > >>> > >> > >> Continue with question from Laurent, > >> > >> How IVSC handle the privacy request from user? Is there some > >> notification mechanism to user-space? IVSC has already defined privacy callback for host IPU/camera driver. > > 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? No data on CSI transmitter side > > > > A V4L2 control can be used for the purpose of passing the information > > to the user space at least. I will take some time to review V4L2 sub-device and control mechanism, and then update the driver. BR, Wentong > > > > -- > Best regards, > Bingbu Cao
