[libcamera-devel] [PATCH v2] ipa: ipu3: Consolidate querying of exposure and gain limits

[Kieran Bingham]

Quoting Umang Jain (2022-03-03 14:14:06)
> Hi,
> 
> On 3/3/22 19:36, Kieran Bingham wrote:
> > Quoting Umang Jain (2022-03-03 12:15:44)
> >> Hi Kieran,
> >>
> >> On 3/3/22 17:17, Kieran Bingham wrote:
> >>> Quoting Umang Jain (2022-03-01 07:59:19)
> >>>> The exposure and gain limits are required for AGC configuration
> >>>> handled in IPAIPU3::updateSessionConfiguration(), which is happening
> >>>> already. Therefore the max/min private members in IPAIPU3 class for
> >>>> exposure/gain serve no use except setting initial values of exposure_
> >>>> and gain_ members.
> >>>>
> >>>> Drop the max/min private members from IPAIPU3 class and set initial
> >>>> gain_ and exposure_ in  IPAIPU3::updateSessionConfiguration().
> >>> Great, even better to drop them if they aren't used.
> >>>
> >>> This looks like we're on the path to removing the private variables for
> >>> controls from the IPAIPU3 now, as they should all be stored in the
> >>> context if there's any relationship with the algorithms.
> >>
> >> yeah, we are on that path.
> >>
> >>> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> >>>
> >>>> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> >>>> ---
> >>>> Changes in v2:
> >>>>    - Split into separate patch
> >>>>    - Prepped over "v4 ipa: ipu3: Misc clean up"
> >>>>    - Don't include max/min exposure/gain members in
> >>>>      IPASessionConfiguration, as they aren't used anywhere.
> >>>> ---
> >>>>    src/ipa/ipu3/ipu3.cpp | 26 ++------------------------
> >>>>    1 file changed, 2 insertions(+), 24 deletions(-)
> >>>>
> >>>> diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
> >>>> index 17324616..4b6852a7 100644
> >>>> --- a/src/ipa/ipu3/ipu3.cpp
> >>>> +++ b/src/ipa/ipu3/ipu3.cpp
> >>>> @@ -167,11 +167,7 @@ private:
> >>>>           /* Camera sensor controls. */
> >>>>           uint32_t defVBlank_;
> >>>>           uint32_t exposure_;
> >>>> -       uint32_t minExposure_;
> >>>> -       uint32_t maxExposure_;
> >>>>           uint32_t gain_;
> >>>> -       uint32_t minGain_;
> >>>> -       uint32_t maxGain_;
> >>> What's required to get rid of gain_, exposure_ and defVBlank_ from here
> >>> too?
> >>
> >> we can drop gain_, exposure_ and replace them with local vars, no issue
> >> in that.
> >>
> >> defVBlank_ seems to be used IPAIPU3 class functions directly, but i
> >> think we can move the defVBlank_ to JM's introduction of
> >> IPASessionConfiguration.sensor structure
> >>
> >> With this plan i think we can drop these remaining private members from
> >> IPAIPU3.
> > Great, can easily be patches on top - doesn't need to be in this one.
> 
> 
> Ok.
> 
> I have been thinking to introduce similar control-not-found error 
> checks(as removed in this patch) in updateSessionConfiguration(), since 
> we ll end up querying the exposure, gain, vblank controls there /only/ . 
> Might as well introduce the control-not-found error checks there.

Aha, I assumed the checks were already there.

We should certainly have checks that the controls are available,
otherwise it can crash when it tries to access them.

I wonder if we can skip the checks if they are Mandatory Controls as
defined by the CameraSensor class though ...

--
Kieran


> 
> >
> > --
> > Kieran
> >
> >
> >>> --
> >>> Kieran
> >>>
> >>>
> >>>>    
> >>>>           /* Interface to the Camera Helper */
> >>>>           std::unique_ptr<CameraSensorHelper> camHelper_;
> >>>> @@ -192,10 +188,12 @@ void IPAIPU3::updateSessionConfiguration(const ControlInfoMap &sensorControls)
> >>>>           const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
> >>>>           int32_t minExposure = v4l2Exposure.min().get<int32_t>();
> >>>>           int32_t maxExposure = v4l2Exposure.max().get<int32_t>();
> >>>> +       exposure_ = minExposure;
> >>>>    
> >>>>           const ControlInfo &v4l2Gain = sensorControls.find(V4L2_CID_ANALOGUE_GAIN)->second;
> >>>>           int32_t minGain = v4l2Gain.min().get<int32_t>();
> >>>>           int32_t maxGain = v4l2Gain.max().get<int32_t>();
> >>>> +       gain_ = minGain;
> >>>>    
> >>>>           /*
> >>>>            * When the AGC computes the new exposure values for a frame, it needs
> >>>> @@ -429,32 +427,12 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
> >>>>            */
> >>>>           ctrls_ = configInfo.sensorControls;
> >>>>    
> >>>> -       const auto itExp = ctrls_.find(V4L2_CID_EXPOSURE);
> >>>> -       if (itExp == ctrls_.end()) {
> >>>> -               LOG(IPAIPU3, Error) << "Can't find exposure control";
> >>>> -               return -EINVAL;
> >>>> -       }
> >>>> -
> >>>> -       const auto itGain = ctrls_.find(V4L2_CID_ANALOGUE_GAIN);
> >>>> -       if (itGain == ctrls_.end()) {
> >>>> -               LOG(IPAIPU3, Error) << "Can't find gain control";
> >>>> -               return -EINVAL;
> >>>> -       }
> >>>> -
> >>>>           const auto itVBlank = ctrls_.find(V4L2_CID_VBLANK);
> >>>>           if (itVBlank == ctrls_.end()) {
> >>>>                   LOG(IPAIPU3, Error) << "Can't find VBLANK control";
> >>>>                   return -EINVAL;
> >>>>           }
> >>>>    
> >>>> -       minExposure_ = itExp->second.min().get<int32_t>();
> >>>> -       maxExposure_ = itExp->second.max().get<int32_t>();
> >>>> -       exposure_ = minExposure_;
> >>>> -
> >>>> -       minGain_ = itGain->second.min().get<int32_t>();
> >>>> -       maxGain_ = itGain->second.max().get<int32_t>();
> >>>> -       gain_ = minGain_;
> >>>> -
> >>>>           defVBlank_ = itVBlank->second.def().get<int32_t>();
> >>>>    
> >>>>           calculateBdsGrid(configInfo.bdsOutputSize);
> >>>> -- 
> >>>> 2.31.1
> >>>>