[PATCH v3 1/6] libcamera: software_isp: Emit ispStatsReady only if IPA is running

[Milan Zamazal]

Software ISP runs debayering in a separate thread and debayering may
emit statsReady when software ISP (including the IPA) is being stopped.
The signal waits in a queue and gets invoked later, resulting in an
assertion error when attempting to invoke a method on the stopped IPA:

  FATAL default soft_ipa_proxy.cpp:456 assertion
  "state_ == ProxyRunning" failed in processStatsThread()

Let's prevent this problem by forwarding the ISP stats signal from
software ISP only when the IPA is running.  To track this,
SoftwareISP::running_ variable is introduced.

Making processing of the other signals in SoftwareISP more robust is
addressed in the followup patches.

Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
Reported-by: Stanislaw Gruszka <stanislaw.gruszka at linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 include/libcamera/internal/software_isp/software_isp.h | 1 +
 src/libcamera/software_isp/software_isp.cpp            | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/libcamera/internal/software_isp/software_isp.h b/include/libcamera/internal/software_isp/software_isp.h
index 440a296d..af0dcc24 100644
--- a/include/libcamera/internal/software_isp/software_isp.h
+++ b/include/libcamera/internal/software_isp/software_isp.h
@@ -100,6 +100,7 @@ private:
 	DmaBufAllocator dmaHeap_;
 
 	std::unique_ptr<ipa::soft::IPAProxySoft> ipa_;
+	bool running_;
 };
 
 } /* namespace libcamera */
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index 44baf200..1a39f4d8 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -315,6 +315,7 @@ int SoftwareIsp::start()
 	int ret = ipa_->start();
 	if (ret)
 		return ret;
+	running_ = true;
 
 	ispWorkerThread_.start();
 	return 0;
@@ -328,6 +329,7 @@ void SoftwareIsp::stop()
 	ispWorkerThread_.exit();
 	ispWorkerThread_.wait();
 
+	running_ = false;
 	ipa_->stop();
 }
 
@@ -356,7 +358,8 @@ void SoftwareIsp::setSensorCtrls(const ControlList &sensorControls)
 
 void SoftwareIsp::statsReady(uint32_t frame, uint32_t bufferId)
 {
-	ispStatsReady.emit(frame, bufferId);
+	if (running_)
+		ispStatsReady.emit(frame, bufferId);
 }
 
 void SoftwareIsp::inputReady(FrameBuffer *input)
-- 
2.48.1