test: camera: Increase timeout for vimc capture tests

On slower machines, a 1s timeout to capture frames with vimc can be too
short and cause test failures. Make the timeout proportional to the
number of frames expected to be captured, using a conservative low
estimate of the frame rate at 2fps.

By itself, that change could increase the test time quite substantially
on fast platforms, so break from the capture loop as soon as we capture
enough frames. To do so, interrupt the dispatcher at every request
completion, or it will only get interrupted after the timer times out.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>

test/camera/buffer_import.cpp

@@ -63,6 +63,8 @@ protected:
 		request->reuse();
 		request->addBuffer(stream, buffer);
 		camera_->queueRequest(request);
+
+		dispatcher_->interrupt();
 	}
 
 	int init() override
@@ -76,6 +78,8 @@ protected:
 			return TestFail;
 		}
 
+		dispatcher_ = Thread::current()->eventDispatcher();
+
 		return TestPass;
 	}
 
@@ -133,17 +137,20 @@ protected:
 			}
 		}
 
-		EventDispatcher *dispatcher = Thread::current()->eventDispatcher();
+		const unsigned int nFrames = cfg.bufferCount * 2;
 
 		Timer timer;
-		timer.start(1000ms);
-		while (timer.isRunning())
-			dispatcher->processEvents();
+		timer.start(500ms * nFrames);
+		while (timer.isRunning()) {
+			dispatcher_->processEvents();
+			if (completeRequestsCount_ > nFrames)
+				break;
+		}
 
-		if (completeRequestsCount_ < cfg.bufferCount * 2) {
+		if (completeRequestsCount_ < nFrames) {
 			std::cout << "Failed to capture enough frames (got "
 				  << completeRequestsCount_ << " expected at least "
-				  << cfg.bufferCount * 2 << ")" << std::endl;
+				  << nFrames << ")" << std::endl;
 			return TestFail;
 		}
 
@@ -161,6 +168,8 @@ protected:
 	}
 
 private:
+	EventDispatcher *dispatcher_;
+
 	std::vector<std::unique_ptr<Request>> requests_;
 
 	unsigned int completeBuffersCount_;