[PATCH 5/5] media: iris: Recycle decoder buffers for non-display pictures

[Xilin Wu]

HFI gen2 reports non-display pictures with HFI_GEN2_PICTURE_NOSHOW, but
Iris returns them as errors. For AV1, hidden and displayed pictures can
share a timestamp, so GStreamer's v4l2av1dec drops the pending frame and
loses the displayed picture.

Recycle successful non-display buffers within the driver instead of
returning them to userspace as errors. This also fixes VP9 streams using
hidden alt-ref frames.

Fixes: ac72ad9deafa ("media: iris: Add handling for no show frames")
Signed-off-by: Xilin Wu <sophon@xxxxxxxxx>
---
 drivers/media/platform/qcom/iris/iris_hfi_gen2.h   |  2 +
 .../platform/qcom/iris/iris_hfi_gen2_command.c     | 11 ++++-
 .../platform/qcom/iris/iris_hfi_gen2_response.c    | 47 ++++++++++++++++++++--
 3 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2.h b/drivers/media/platform/qcom/iris/iris_hfi_gen2.h
index 21ab58e0aa84..79aac2d4e500 100644
--- a/drivers/media/platform/qcom/iris/iris_hfi_gen2.h
+++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2.h
@@ -20,6 +20,7 @@ struct iris_core;
  * @packet: HFI packet
  * @ipsc_properties_set: boolean to set ipsc properties to fw
  * @opsc_properties_set: boolean to set opsc properties to fw
+ * @output_stopping: capture STOP command is awaiting its response
  * @hfi_frame_info: structure of frame info
  * @src_subcr_params: subscription params to fw on input port
  * @dst_subcr_params: subscription params to fw on output port
@@ -29,6 +30,7 @@ struct iris_inst_hfi_gen2 {
 	struct iris_hfi_header		*packet;
 	bool				ipsc_properties_set;
 	bool				opsc_properties_set;
+	bool				output_stopping;
 	struct iris_hfi_frame_info	hfi_frame_info;
 	struct hfi_subscription_params	src_subcr_params;
 	struct hfi_subscription_params	dst_subcr_params;
diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c b/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c
index a285e6fc8728..77ea153bf2d7 100644
--- a/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c
+++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c
@@ -1172,7 +1172,16 @@ static int iris_hfi_gen2_session_stop(struct iris_inst *inst, u32 plane)
 	if (ret)
 		return ret;
 
-	return iris_wait_for_session_response(inst, false);
+	/* The response wait drops inst->lock, allowing buffers to be returned. */
+	if (plane == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
+		inst_hfi_gen2->output_stopping = true;
+
+	ret = iris_wait_for_session_response(inst, false);
+
+	if (plane == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
+		inst_hfi_gen2->output_stopping = false;
+
+	return ret;
 }
 
 static int iris_hfi_gen2_session_pause(struct iris_inst *inst, u32 plane)
diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c b/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c
index f0782c4b1e6e..a545410d1e8d 100644
--- a/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c
+++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c
@@ -101,9 +101,7 @@ static int iris_hfi_gen2_get_driver_buffer_flags(struct iris_inst *inst, u32 hfi
 		HFI_GEN2_PICTURE_CRA | HFI_GEN2_PICTURE_BLA;
 	u32 driver_flags = 0;
 
-	if (inst_hfi_gen2->hfi_frame_info.picture_type & HFI_GEN2_PICTURE_NOSHOW)
-		driver_flags |= V4L2_BUF_FLAG_ERROR;
-	else if (inst_hfi_gen2->hfi_frame_info.picture_type & keyframe)
+	if (inst_hfi_gen2->hfi_frame_info.picture_type & keyframe)
 		driver_flags |= V4L2_BUF_FLAG_KEYFRAME;
 	else if (inst_hfi_gen2->hfi_frame_info.picture_type & HFI_GEN2_PICTURE_P)
 		driver_flags |= V4L2_BUF_FLAG_PFRAME;
@@ -345,9 +343,40 @@ static int iris_hfi_gen2_handle_input_buffer(struct iris_inst *inst,
 	return 0;
 }
 
+static int iris_hfi_gen2_requeue_output_buffer(struct iris_inst *inst,
+					       struct iris_buffer *buf)
+{
+	struct iris_inst_hfi_gen2 *inst_hfi_gen2 = to_iris_inst_hfi_gen2(inst);
+	u64 timestamp = buf->timestamp;
+	int ret;
+
+	buf->data_size = 0;
+	buf->timestamp = 0;
+	buf->flags = 0;
+	buf->attr &= ~BUF_ATTR_DEQUEUED;
+	buf->attr |= BUF_ATTR_DEFERRED;
+
+	/* Leave stopped buffers for streamoff cleanup or the next streamon. */
+	if (inst_hfi_gen2->output_stopping ||
+	    (inst->state != IRIS_INST_STREAMING &&
+	     inst->state != IRIS_INST_OUTPUT_STREAMING))
+		return 0;
+
+	ret = iris_queue_buffer(inst, buf);
+	if (ret) {
+		buf->attr &= ~BUF_ATTR_DEFERRED;
+		buf->attr |= BUF_ATTR_DEQUEUED;
+		buf->flags = V4L2_BUF_FLAG_ERROR;
+		buf->timestamp = timestamp;
+	}
+
+	return ret;
+}
+
 static int iris_hfi_gen2_handle_output_buffer(struct iris_inst *inst,
 					      struct iris_hfi_buffer *hfi_buffer)
 {
+	struct iris_inst_hfi_gen2 *inst_hfi_gen2 = to_iris_inst_hfi_gen2(inst);
 	struct v4l2_m2m_ctx *m2m_ctx = inst->m2m_ctx;
 	struct v4l2_m2m_buffer *m2m_buffer, *n;
 	struct iris_buffer *buf;
@@ -390,8 +419,18 @@ static int iris_hfi_gen2_handle_output_buffer(struct iris_inst *inst,
 
 	buf->flags = iris_hfi_gen2_get_driver_buffer_flags(inst, hfi_buffer->flags);
 
+	if (inst->domain == DECODER &&
+	    inst_hfi_gen2->hfi_frame_info.picture_type & HFI_GEN2_PICTURE_NOSHOW) {
+		/* A hidden reference picture is neither a display frame nor an error. */
+		buf->data_size = 0;
+		if (inst->state == IRIS_INST_ERROR)
+			buf->flags |= V4L2_BUF_FLAG_ERROR;
+		if (!(buf->flags & (V4L2_BUF_FLAG_ERROR | V4L2_BUF_FLAG_LAST)))
+			return iris_hfi_gen2_requeue_output_buffer(inst, buf);
+	}
+
 	if (!buf->data_size && inst->state == IRIS_INST_STREAMING &&
-	    !(hfi_buffer->flags & HFI_BUF_FW_FLAG_LAST)) {
+	    !(buf->flags & V4L2_BUF_FLAG_LAST)) {
 		buf->flags |= V4L2_BUF_FLAG_ERROR;
 	}
 

-- 
2.56.0