Re: [PATCH] ACPI: scan: Honor _DEP for Intel CVS devices

[Rafael J. Wysocki (Intel)]

On Sun, Sep 13, 2026 at 10:30 AM Thorsten Leemhuis
<regressions@xxxxxxxxxxxxx> wrote:
>
> On 9/12/26 18:50, Thorsten Leemhuis wrote:
> > On 6/1/26 21:40, Miguel Vadillo wrote:
> >> CVS (Computer Vision Sensing) is an ACPI-enumerated device that sits
> >> inline in the CSI-2 path between the camera sensor and Intel IPU.
> >> On platforms where CVS is present, the camera sensor's ACPI node
> >> declares a _DEP dependency on the CVS device.
> >>
> >> The CVS driver must be fully initialized before camera sensor drivers
> >> probe, because CVS controls the CSI-2 link ownership handshake (via
> >> GPIO REQ/RESP), the MIPI/CSI-2 lane configuration, and the camera
> >> power domain. Without CVS ready, the sensor driver can bind but the
> >> CSI-2 stream will not function correctly.
> >>
> >> The CVS driver calls acpi_dev_clear_dependencies() at the end of its
> >> probe() to unblock waiting consumers once it is ready.
> >>
> >> Move the CVS HIDs from acpi_ignore_dep_ids[] to acpi_honor_dep_ids[]
> >> so that camera sensor enumeration is deferred until the CVS driver has
> >> finished probing, matching the behavior already in place for IVSC.
> >
> > TWIMC, there is a bug report where one or two people claim that this
> > change caused a regression; the report is quite verbose (guess LLM
> > assisted) and hard to grasp for me as outsider; requests for
> > clarifications from my side were not really fruitful. Not sure what to
> > make of this, but I thought I'd let you know; for details see:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=221988
>
> For completeness, a report that is more straight forward to read (at
> least for me) was now posted here:
> https://lore.kernel.org/all/20260912185836.309071-1-manuel.knitza@xxxxxxxxxxxxxx/

This doesn't seem to be about the same commit though as it mentions
ipu-bridge.c which is not touched by the patch in question here.

Thanks!