[PATCH v5 05/14] media: mtk-vcodec: venc: support START and STOP commands

From: Alexandre Courbot
Date: Wed May 19 2021 - 10:31:00 EST


The V4L2 encoder specification requires encoders to support the
V4L2_ENC_CMD_START and V4L2_ENC_CMD_STOP commands. Add support for these
to the mtk-vcodec encoder by reusing the same flush buffer as used by
the decoder driver.

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
[hsinyi: fix double-free issue if flush buffer was not dequeued by the
time streamoff is called]
Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
---
.../platform/mtk-vcodec/mtk_vcodec_drv.h | 2 +
.../platform/mtk-vcodec/mtk_vcodec_enc.c | 135 +++++++++++++++++-
.../platform/mtk-vcodec/mtk_vcodec_enc_drv.c | 4 +
3 files changed, 134 insertions(+), 7 deletions(-)

diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
index c6fe61253f43..37a62c0f406f 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
@@ -252,6 +252,7 @@ struct vdec_pic_info {
* @last_decoded_picinfo: pic information get from latest decode
* @empty_flush_buf: a fake size-0 capture buffer that indicates flush. Only
* to be used with encoder and stateful decoder.
+ * @is_flushing: set to true if flushing is in progress.
*
* @colorspace: enum v4l2_colorspace; supplemental to pixelformat
* @ycbcr_enc: enum v4l2_ycbcr_encoding, Y'CbCr encoding
@@ -290,6 +291,7 @@ struct mtk_vcodec_ctx {
struct work_struct encode_work;
struct vdec_pic_info last_decoded_picinfo;
struct v4l2_m2m_buffer empty_flush_buf;
+ bool is_flushing;

enum v4l2_colorspace colorspace;
enum v4l2_ycbcr_encoding ycbcr_enc;
diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c
index 4831052f475d..4701dea251ca 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc.c
@@ -659,6 +659,7 @@ static int vidioc_venc_dqbuf(struct file *file, void *priv,
struct v4l2_buffer *buf)
{
struct mtk_vcodec_ctx *ctx = fh_to_ctx(priv);
+ int ret;

if (ctx->state == MTK_STATE_ABORT) {
mtk_v4l2_err("[%d] Call on QBUF after unrecoverable error",
@@ -666,7 +667,77 @@ static int vidioc_venc_dqbuf(struct file *file, void *priv,
return -EIO;
}

- return v4l2_m2m_dqbuf(file, ctx->m2m_ctx, buf);
+ ret = v4l2_m2m_dqbuf(file, ctx->m2m_ctx, buf);
+ if (ret)
+ return ret;
+
+ /*
+ * Complete flush if the user dequeued the 0-payload LAST buffer.
+ * We check the payload because a buffer with the LAST flag can also
+ * be seen during resolution changes. If we happen to be flushing at
+ * that time, the last buffer before the resolution changes could be
+ * misinterpreted for the buffer generated by the flush and terminate
+ * it earlier than we want.
+ */
+ if (!V4L2_TYPE_IS_OUTPUT(buf->type) &&
+ buf->flags & V4L2_BUF_FLAG_LAST &&
+ buf->m.planes[0].bytesused == 0 &&
+ ctx->is_flushing) {
+ /*
+ * Last CAPTURE buffer is dequeued, we can allow another flush
+ * to take place.
+ */
+ ctx->is_flushing = false;
+ }
+
+ return 0;
+}
+
+static int vidioc_encoder_cmd(struct file *file, void *priv,
+ struct v4l2_encoder_cmd *cmd)
+{
+ struct mtk_vcodec_ctx *ctx = fh_to_ctx(priv);
+ struct vb2_queue *src_vq, *dst_vq;
+ int ret;
+
+ ret = v4l2_m2m_ioctl_try_encoder_cmd(file, priv, cmd);
+ if (ret)
+ return ret;
+
+ /* Calling START or STOP is invalid if a flush is in progress */
+ if (ctx->is_flushing)
+ return -EBUSY;
+
+ mtk_v4l2_debug(1, "encoder cmd=%u", cmd->cmd);
+
+ dst_vq = v4l2_m2m_get_vq(ctx->m2m_ctx,
+ V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
+ switch (cmd->cmd) {
+ case V4L2_ENC_CMD_STOP:
+ src_vq = v4l2_m2m_get_vq(ctx->m2m_ctx,
+ V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
+ if (!vb2_is_streaming(src_vq)) {
+ mtk_v4l2_debug(1, "Output stream is off. No need to flush.");
+ return 0;
+ }
+ if (!vb2_is_streaming(dst_vq)) {
+ mtk_v4l2_debug(1, "Capture stream is off. No need to flush.");
+ return 0;
+ }
+ ctx->is_flushing = true;
+ v4l2_m2m_buf_queue(ctx->m2m_ctx, &ctx->empty_flush_buf.vb);
+ v4l2_m2m_try_schedule(ctx->m2m_ctx);
+ break;
+
+ case V4L2_ENC_CMD_START:
+ vb2_clear_last_buffer_dequeued(dst_vq);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
}

const struct v4l2_ioctl_ops mtk_venc_ioctl_ops = {
@@ -702,6 +773,9 @@ const struct v4l2_ioctl_ops mtk_venc_ioctl_ops = {

.vidioc_g_selection = vidioc_venc_g_selection,
.vidioc_s_selection = vidioc_venc_s_selection,
+
+ .vidioc_encoder_cmd = vidioc_encoder_cmd,
+ .vidioc_try_encoder_cmd = v4l2_m2m_ioctl_try_encoder_cmd,
};

static int vb2ops_venc_queue_setup(struct vb2_queue *vq,
@@ -869,9 +943,39 @@ static void vb2ops_venc_stop_streaming(struct vb2_queue *q)
dst_buf->vb2_buf.planes[0].bytesused = 0;
v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_ERROR);
}
+ /* STREAMOFF on the CAPTURE queue completes any ongoing flush */
+ if (ctx->is_flushing) {
+ struct v4l2_m2m_buffer *b, *n;
+
+ mtk_v4l2_debug(1, "STREAMOFF called while flushing");
+ /*
+ * STREAMOFF could be called before the flush buffer is
+ * dequeued. Check whether empty flush buf is still in
+ * queue before removing it.
+ */
+ v4l2_m2m_for_each_src_buf_safe(ctx->m2m_ctx, b, n) {
+ if (b == &ctx->empty_flush_buf) {
+ v4l2_m2m_src_buf_remove_by_buf(
+ ctx->m2m_ctx, &b->vb);
+ break;
+ }
+ }
+ ctx->is_flushing = false;
+ }
} else {
- while ((src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx)))
- v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
+ while ((src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx))) {
+ if (src_buf != &ctx->empty_flush_buf.vb)
+ v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
+ }
+ if (ctx->is_flushing) {
+ /*
+ * If we are in the middle of a flush, put the flush
+ * buffer back into the queue so the next CAPTURE
+ * buffer gets returned with the LAST flag set.
+ */
+ v4l2_m2m_buf_queue(ctx->m2m_ctx,
+ &ctx->empty_flush_buf.vb);
+ }
}

if ((q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE &&
@@ -971,12 +1075,15 @@ static int mtk_venc_param_change(struct mtk_vcodec_ctx *ctx)
{
struct venc_enc_param enc_prm;
struct vb2_v4l2_buffer *vb2_v4l2 = v4l2_m2m_next_src_buf(ctx->m2m_ctx);
- struct mtk_video_enc_buf *mtk_buf =
- container_of(vb2_v4l2, struct mtk_video_enc_buf,
- m2m_buf.vb);
-
+ struct mtk_video_enc_buf *mtk_buf;
int ret = 0;

+ /* Don't upcast the empty flush buffer */
+ if (vb2_v4l2 == &ctx->empty_flush_buf.vb)
+ return 0;
+
+ mtk_buf = container_of(vb2_v4l2, struct mtk_video_enc_buf, m2m_buf.vb);
+
memset(&enc_prm, 0, sizeof(enc_prm));
if (mtk_buf->param_change == MTK_ENCODE_PARAM_NONE)
return 0;
@@ -1062,6 +1169,20 @@ static void mtk_venc_worker(struct work_struct *work)
}

src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx);
+
+ /*
+ * If we see the flush buffer, send an empty buffer with the LAST flag
+ * to the client. is_flushing will be reset at the time the buffer
+ * is dequeued.
+ */
+ if (src_buf == &ctx->empty_flush_buf.vb) {
+ vb2_set_plane_payload(&dst_buf->vb2_buf, 0, 0);
+ dst_buf->flags |= V4L2_BUF_FLAG_LAST;
+ v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_DONE);
+ v4l2_m2m_job_finish(ctx->dev->m2m_dev_enc, ctx->m2m_ctx);
+ return;
+ }
+
memset(&frm_buf, 0, sizeof(frm_buf));
for (i = 0; i < src_buf->vb2_buf.num_planes ; i++) {
frm_buf.fb_addr[i].dma_addr =
diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_drv.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_drv.c
index 7d7b8cfc2cc5..2dd6fef896df 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_drv.c
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_drv.c
@@ -131,6 +131,7 @@ static int fops_vcodec_open(struct file *file)
struct mtk_vcodec_dev *dev = video_drvdata(file);
struct mtk_vcodec_ctx *ctx = NULL;
int ret = 0;
+ struct vb2_queue *src_vq;

ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
@@ -164,6 +165,9 @@ static int fops_vcodec_open(struct file *file)
ret);
goto err_m2m_ctx_init;
}
+ src_vq = v4l2_m2m_get_vq(ctx->m2m_ctx,
+ V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
+ ctx->empty_flush_buf.vb.vb2_buf.vb2_queue = src_vq;
mtk_vcodec_enc_set_default_params(ctx);

if (v4l2_fh_is_singular(&ctx->fh)) {
--
2.31.1.751.gd2f1c929bd-goog