[PATCH] ipa: rpi: Fix for incorrectly reported max shutter speed

[Naushir Patuck]

On Thu, 9 May 2024 at 11:23, Laurent Pinchart <
laurent.pinchart at ideasonboard.com> wrote:

> Hi Naush,
>
> On Tue, May 07, 2024 at 11:32:54AM +0100, Naushir Patuck wrote:
> > On Sat, 4 May 2024 at 16:04, Laurent Pinchart wrote:
> > > On Wed, May 01, 2024 at 05:04:03PM +0100, Naushir Patuck wrote:
> > > > On Wed, 1 May 2024 at 16:53, Laurent Pinchart wrote:
> > > > > On Fri, Apr 26, 2024 at 12:18:15PM +0100, Naushir Patuck wrote:
> > > > > > The maximum shutter speed calculation in the cam-helper relied on
> > > > > > the frame duration limits being correctly set in the
> cam-helper's mode
> > > > > > structure. This was not the case on first startup, so the maximum
> > > > > > shutter speed reported back via the ControlInfo was incorrect.
> > > > > >
> > > > > > Fix this by setting up the camera mode in the cam-helper before
> querying
> > > > > > for the max shutter value.
> > > > > >
> > > > > > Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> > > > > > ---
> > > > > >  src/ipa/rpi/common/ipa_base.cpp | 6 ++++++
> > > > > >  1 file changed, 6 insertions(+)
> > > > > >
> > > > > > diff --git a/src/ipa/rpi/common/ipa_base.cpp
> b/src/ipa/rpi/common/ipa_base.cpp
> > > > > > index 149a133ab662..1d12262bda01 100644
> > > > > > --- a/src/ipa/rpi/common/ipa_base.cpp
> > > > > > +++ b/src/ipa/rpi/common/ipa_base.cpp
> > > > > > @@ -592,6 +592,12 @@ void IpaBase::setMode(const
> IPACameraSensorInfo &sensorInfo)
> > > > > >       mode_.minAnalogueGain =
> helper_->gain(gainCtrl.min().get<int32_t>());
> > > > > >       mode_.maxAnalogueGain =
> helper_->gain(gainCtrl.max().get<int32_t>());
> > > > > >
> > > > > > +     /*
> > > > > > +      * We need to give the helper the min/max frame durations
> so it can calculate
> > > > > > +      * the correct exposure limits below.
> > > > > > +      */
> > > > > > +     helper_->setCameraMode(mode_);
> > > > > > +
> > > > >
> > > > > Don't you end up doing this twice, once here, and once in
> > > > > IpaBase::configure(), which calls IpaBase::setMode() ?
> > > >
> > > > Yes, it does happen twice.  The other option would be to pass a const
> > > > reference to mode_ into the helper through setMode(), allowing us
> only do
> > > > it once.
> > >
> > > I don't think I follow you.
> >
> > What I mean is that we don't give the cam helper its own copy of the
> > mode structure, but pass it a const reference to the IPA's mode
> > structure.   This would solve the problem with the calculation here.
>
> It's probably me, but I still don't get it :-) We have
>
> void CamHelper::setCameraMode(const CameraMode &mode)
> {
>         mode_ = mode;
>         if (parser_) {
>                 parser_->reset();
>                 parser_->setBitsPerPixel(mode.bitdepth);
>                 parser_->setLineLengthBytes(0); /* We use SetBufferSize. */
>         }
> }
>
> called in IpaBase::configure(). This patch adds another call in
> IpaBase::setMode(). You wrote
>
> > The other option would be to pass a const reference to mode_ into the
> > helper through setMode()
>
> Doesn't this patch does exactly that ? How is it another option ?
>
> /me is confused


In CamHelper::setCameraMode(const CameraMode &mode), I would have to store
the const reference rather than make a copy of CameraMode mode:

diff --git a/src/ipa/rpi/cam_helper/cam_helper.h
b/src/ipa/rpi/cam_helper/cam_helper.h
index 58a4b202d5a8..eb2a56484606 100644
--- a/src/ipa/rpi/cam_helper/cam_helper.h
+++ b/src/ipa/rpi/cam_helper/cam_helper.h
@@ -107,7 +107,7 @@ protected:
                                      Metadata &metadata) const;

        std::unique_ptr<MdParser> parser_;
-       CameraMode mode_;
+       const CameraMode &mode_;

Then in the IPA if I call CamHelper::setCameraMode()
before IpaBase::setMode() + a bit of other refactoring, I think I can
achieve what I want without a double call..  The "other bit of refactoring"
is the bit I'm a bit hesitant to work on for such a simple fix :)

Regards,
Naush


>
> > > > But that was a bit more involved over this more trivial fix.  I
> > > > can change to do that if folks prefer.
> > > >
> > > > > >       /* Shutter speed is calculated based on the limits of the
> frame durations. */
> > > > > >       mode_.minShutter =
> helper_->exposure(shutterCtrl.min().get<int32_t>(), mode_.minLineLength);
> > > > > >       mode_.maxShutter = Duration::max();
>
> --
> Regards,
>
> Laurent Pinchart
>
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