RE: [PATCH v3 3/3] ACPI: delay enumeration of devices with a _DEP pointing to INTC1059 device

["Wu, Wentong" <wentong.wu@intel.com>]

> -----Original Message-----
> From: Sakari Ailus <sakari.ailus@linux.intel.com>
> Sent: Monday, March 27, 2023 3:33 PM
> 
> Hi Wentong,
> 
> On Mon, Mar 27, 2023 at 07:17:13AM +0000, Wu, Wentong wrote:
> >
> >
> > > -----Original Message-----
> > > From: Sakari Ailus <sakari.ailus@linux.intel.com>
> > >
> > > Hi Wentong,
> > >
> > > On Mon, Mar 27, 2023 at 02:23:08PM +0800, Wentong Wu wrote:
> > > > Inside IVSC, switching ownership requires an interface with two
> > > > different hardware modules, ACE and CSI. The software interface to
> > > > these modules is based on Intel MEI framework. Usually mei client
> > > > devices are dynamically created, so the info of consumers
> > > > depending on mei client devices is not present in the firmware tables.
> > >
> > > Ouch.
> >
> > MEI client devices are not ACPI devices in our case.
> >
> > >
> > > >
> > > > This causes problems with the probe ordering with respect to
> > > > drivers for consumers of these mei client devices. But on these
> > > > camera sensor devices, the ACPI nodes describing the sensors all
> > > > have a _DEP dependency on the matching INTC1059 ACPI device, so
> > > > adding INTC1059 to acpi_honor_dep_ids allows solving the
> > > > probe-ordering problem by delaying the enumeration of ACPI-devices
> > > > which have a _DEP dependency on
> > > an INTC1059 device.
> > >
> > > What does the INTC1059 device represent?
> >
> > This is the IVSC device on which camera sensor has _DEP
> >
> >             Device (CVFD)
> >             {
> >                 Name (_HID, "INTC1059")  // _HID: Hardware ID
> >                 Name (_DDN, "Intel CVF Device")  // _DDN: DOS Device Name
> >                 Method (SID, 1, Serialized)
> >                 {
> >                     Return (HCID (One))
> >                 }
> >             }
> 
> Should this be interpreted that if you have a _DEP to this device, then the IVSC is
> between the sensor and the IPU?

Ok, I can explain more in next version patch set. Thanks

BR,
Wentong

> 
> --
> Kind regards,
> 
> Sakari Ailus