media: venus: reimplement decoder stop command

This addresses the wrong behavior of decoder stop command by
rewriting it. These new implementation enqueue an empty buffer
on the decoder input buffer queue to signal end-of-stream. The
client should stop queuing buffers on the V4L2 Output queue
and continue queuing/dequeuing buffers on Capture queue. This
process will continue until the client receives a buffer with
V4L2_BUF_FLAG_LAST flag raised, which means that this is last
decoded buffer with data.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Tested-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org>      # for v4.13 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/qcom/venus/core.h

@@ -194,7 +194,6 @@ struct venus_buffer {
  * @fh:	 a holder of v4l file handle structure
  * @streamon_cap: stream on flag for capture queue
  * @streamon_out: stream on flag for output queue
- * @cmd_stop:	a flag to signal encoder/decoder commands
  * @width:	current capture width
  * @height:	current capture height
  * @out_width:	current output width
@@ -258,7 +257,6 @@ struct venus_inst {
 	} controls;
 	struct v4l2_fh fh;
 	unsigned int streamon_cap, streamon_out;
-	bool cmd_stop;
 	u32 width;
 	u32 height;
 	u32 out_width;

drivers/media/platform/qcom/venus/helpers.c

@@ -623,13 +623,6 @@ void venus_helper_vb2_buf_queue(struct vb2_buffer *vb)
 
 	mutex_lock(&inst->lock);
 
-	if (inst->cmd_stop) {
-		vbuf->flags |= V4L2_BUF_FLAG_LAST;
-		v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_DONE);
-		inst->cmd_stop = false;
-		goto unlock;
-	}
-
 	v4l2_m2m_buf_queue(m2m_ctx, vbuf);
 
 	if (!(inst->streamon_out & inst->streamon_cap))

drivers/media/platform/qcom/venus/hfi.c

@@ -484,6 +484,7 @@ int hfi_session_process_buf(struct venus_inst *inst, struct hfi_frame_data *fd)
 
 	return -EINVAL;
 }
+EXPORT_SYMBOL_GPL(hfi_session_process_buf);
 
 irqreturn_t hfi_isr_thread(int irq, void *dev_id)
 {

drivers/media/platform/qcom/venus/vdec.c

@@ -469,8 +469,14 @@ static int vdec_subscribe_event(struct v4l2_fh *fh,
 static int
 vdec_try_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd *cmd)
 {
-	if (cmd->cmd != V4L2_DEC_CMD_STOP)
+	switch (cmd->cmd) {
+	case V4L2_DEC_CMD_STOP:
+		if (cmd->flags & V4L2_DEC_CMD_STOP_TO_BLACK)
+			return -EINVAL;
+		break;
+	default:
 		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -479,6 +485,7 @@ static int
 vdec_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd *cmd)
 {
 	struct venus_inst *inst = to_inst(file);
+	struct hfi_frame_data fdata = {0};
 	int ret;
 
 	ret = vdec_try_decoder_cmd(file, fh, cmd);
@@ -486,12 +493,23 @@ vdec_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd *cmd)
 		return ret;
 
 	mutex_lock(&inst->lock);
-	inst->cmd_stop = true;
-	mutex_unlock(&inst->lock);
 
-	hfi_session_flush(inst);
+	/*
+	 * Implement V4L2_DEC_CMD_STOP by enqueue an empty buffer on decoder
+	 * input to signal EOS.
+	 */
+	if (!(inst->streamon_out & inst->streamon_cap))
+		goto unlock;
+
+	fdata.buffer_type = HFI_BUFFER_INPUT;
+	fdata.flags |= HFI_BUFFERFLAG_EOS;
+	fdata.device_addr = 0xdeadbeef;
 
-	return 0;
+	ret = hfi_session_process_buf(inst, &fdata);
+
+unlock:
+	mutex_unlock(&inst->lock);
+	return ret;
 }
 
 static const struct v4l2_ioctl_ops vdec_ioctl_ops = {
@@ -718,7 +736,6 @@ static int vdec_start_streaming(struct vb2_queue *q, unsigned int count)
 	inst->reconfig = false;
 	inst->sequence_cap = 0;
 	inst->sequence_out = 0;
-	inst->cmd_stop = false;
 
 	ret = vdec_init_session(inst);
 	if (ret)
@@ -807,11 +824,6 @@ static void vdec_buf_done(struct venus_inst *inst, unsigned int buf_type,
 		vb->timestamp = timestamp_us * NSEC_PER_USEC;
 		vbuf->sequence = inst->sequence_cap++;
 
-		if (inst->cmd_stop) {
-			vbuf->flags |= V4L2_BUF_FLAG_LAST;
-			inst->cmd_stop = false;
-		}
-
 		if (vbuf->flags & V4L2_BUF_FLAG_LAST) {
 			const struct v4l2_event ev = { .type = V4L2_EVENT_EOS };