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

[Umang Jain]

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.

>
> --
> 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
>>