media: amphion: defer setting last_buffer_dequeued until resolution changes are processed

Don't set last_buffer_dequeued during dynamic resolution change,
otherwise it may be cleared in handling resolution change,
as streamoff may be called in dynamic resolution change.

Normally, this does not happen.
But we encounter a special testcase,
User issue V4L2_DEC_CMD_STOP after enqueue one buffer
that only contains codec config header, but not any frame data.
So VPU report the parsed resolution, then report the eos event.

So driver should notify user to handle resolution change first,
after it's handled, set the last_buffer_dequeued.
then the user can exit decoding normally.

Otherwise the user may be stalled.

Fixes: 6de8d628df ("media: amphion: add v4l2 m2m vpu decoder stateful driver")
Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/amphion/vdec.c

@@ -178,16 +178,6 @@ static int vdec_ctrl_init(struct vpu_inst *inst)
 	return 0;
 }
 
-static void vdec_set_last_buffer_dequeued(struct vpu_inst *inst)
-{
-	struct vdec_t *vdec = inst->priv;
-
-	if (vdec->eos_received) {
-		if (!vpu_set_last_buffer_dequeued(inst))
-			vdec->eos_received--;
-	}
-}
-
 static void vdec_handle_resolution_change(struct vpu_inst *inst)
 {
 	struct vdec_t *vdec = inst->priv;
@@ -234,6 +224,21 @@ static int vdec_update_state(struct vpu_inst *inst, enum vpu_codec_state state,
 	return 0;
 }
 
+static void vdec_set_last_buffer_dequeued(struct vpu_inst *inst)
+{
+	struct vdec_t *vdec = inst->priv;
+
+	if (inst->state == VPU_CODEC_STATE_DYAMIC_RESOLUTION_CHANGE)
+		return;
+
+	if (vdec->eos_received) {
+		if (!vpu_set_last_buffer_dequeued(inst)) {
+			vdec->eos_received--;
+			vdec_update_state(inst, VPU_CODEC_STATE_DRAIN, 0);
+		}
+	}
+}
+
 static int vdec_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
 {
 	strscpy(cap->driver, "amphion-vpu", sizeof(cap->driver));
@@ -493,6 +498,8 @@ static int vdec_drain(struct vpu_inst *inst)
 
 static int vdec_cmd_start(struct vpu_inst *inst)
 {
+	struct vdec_t *vdec = inst->priv;
+
 	switch (inst->state) {
 	case VPU_CODEC_STATE_STARTED:
 	case VPU_CODEC_STATE_DRAIN:
@@ -503,6 +510,8 @@ static int vdec_cmd_start(struct vpu_inst *inst)
 		break;
 	}
 	vpu_process_capture_buffer(inst);
+	if (vdec->eos_received)
+		vdec_set_last_buffer_dequeued(inst);
 	return 0;
 }
 
@@ -1203,7 +1212,6 @@ static void vdec_event_eos(struct vpu_inst *inst)
 	vdec->eos_received++;
 	vdec->fixed_fmt = false;
 	inst->min_buffer_cap = VDEC_MIN_BUFFER_CAP;
-	vdec_update_state(inst, VPU_CODEC_STATE_DRAIN, 0);
 	vdec_set_last_buffer_dequeued(inst);
 	vpu_inst_unlock(inst);
 }
@@ -1479,10 +1487,10 @@ static int vdec_stop_session(struct vpu_inst *inst, u32 type)
 		vdec_update_state(inst, VPU_CODEC_STATE_SEEK, 0);
 		vdec->drain = 0;
 	} else {
-		if (inst->state != VPU_CODEC_STATE_DYAMIC_RESOLUTION_CHANGE)
+		if (inst->state != VPU_CODEC_STATE_DYAMIC_RESOLUTION_CHANGE) {
 			vdec_abort(inst);
-
-		vdec->eos_received = 0;
+			vdec->eos_received = 0;
+		}
 		vdec_clear_slots(inst);
 	}
 

drivers/media/platform/amphion/vpu_v4l2.c

@@ -500,8 +500,8 @@ static int vpu_vb2_start_streaming(struct vb2_queue *q, unsigned int count)
 		  fmt->sizeimage[1], fmt->bytesperline[1],
 		  fmt->sizeimage[2], fmt->bytesperline[2],
 		  q->num_buffers);
-	ret = call_vop(inst, start, q->type);
 	vb2_clear_last_buffer_dequeued(q);
+	ret = call_vop(inst, start, q->type);
 	if (ret)
 		vpu_vb2_buffers_return(inst, q->type, VB2_BUF_STATE_QUEUED);