[libcamera-devel,v3,09/13] pipeline: raspberrypi: Handle MandatoryRequestBuffer hints for ISP Output0
diff mbox series

Message ID 20221206135459.25521-10-naush@raspberrypi.com
State Superseded
Headers show
Series
  • Raspberry Pi: Platform configuration and buffer allocation improvements
Related show

Commit Message

Naushir Patuck Dec. 6, 2022, 1:54 p.m. UTC
Look for MandatoryRequestBuffer flag in the hints field of the ISP Output0
StreamConfiguration structure. If this flag is set, it guarantees that the
application will provide buffers for the ISP, do not allocate any internal
buffers for the device.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
---
 .../pipeline/raspberrypi/raspberrypi.cpp      | 29 ++++++++++++++-----
 1 file changed, 22 insertions(+), 7 deletions(-)

Patch
diff mbox series

diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index 302279ac5e01..371610be649a 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -1470,7 +1470,7 @@  int PipelineHandlerRPi::prepareBuffers(Camera *camera)
 	RPiCameraData *data = cameraData(camera);
 	unsigned int minUnicamBuffers = data->config_.minUnicamBuffers,
 		     minTotalUnicamBuffers = data->config_.minTotalUnicamBuffers,
-		     numRawBuffers = 0;
+		     numRawBuffers = 0, minIspBuffers = 1;
 	int ret;
 
 	for (Stream *s : camera->streams()) {
@@ -1494,8 +1494,21 @@  int PipelineHandlerRPi::prepareBuffers(Camera *camera)
 					minTotalUnicamBuffers = 0;
 				}
 			}
-
-			break;
+		} else if (s == &data->isp_[Isp::Output0]) {
+			/*
+			 * Since the ISP runs synchronous with the IPA and requests,
+			 * we only ever need a maximum of one internal buffer. Any
+			 * buffers the application wants to hold onto will already
+			 * be exported through PipelineHandlerRPi::exportFrameBuffers().
+			 *
+			 * However, as above, if the application provides a guarantee
+			 * that the buffer will always be provided for the ISP Output0
+			 * stream in a Request, we don't need any internal buffers
+			 * allocated.
+			 */
+			if (s->configuration().hints &
+			    StreamConfiguration::Hint::MandatoryRequestBuffer)
+				minIspBuffers = 0;
 		}
 	}
 
@@ -1531,12 +1544,14 @@  int PipelineHandlerRPi::prepareBuffers(Camera *camera)
 			 * so allocate the minimum required to avoid frame drops.
 			 */
 			numBuffers = data->config_.minTotalUnicamBuffers;
+		} else if (stream == &data->isp_[Isp::Output0]) {
+			/* Buffer count for this is handled in the earlier loop above. */
+			numBuffers = minIspBuffers;
 		} else {
 			/*
-			 * Since the ISP runs synchronous with the IPA and requests,
-			 * we only ever need one set of internal buffers. Any buffers
-			 * the application wants to hold onto will already be exported
-			 * through PipelineHandlerRPi::exportFrameBuffers().
+			 * Same reasoning as for ISP Output 0, we only ever need
+			 * a maximum of one internal buffer for Output1 (required
+			 * for colour denoise) and ISP statistics.
 			 */
 			numBuffers = 1;
 		}