Re: [PATCH] venus: venc: add handling for VIDIOC_ENCODER_CMD

From: Alexandre Courbot
Date: Tue Oct 20 2020 - 04:57:44 EST

Hi Dikshita,

On Mon, Oct 19, 2020 at 11:29 PM Dikshita Agarwal
<dikshita@xxxxxxxxxxxxxx> wrote:
>
> Add handling for below commands in encoder:
> 1. V4L2_ENC_CMD_STOP
> 2. V4L2_ENC_CMD_START

I suspect this can be implemented more easily (and more safely) using
the m2m encoder helpers introduced recently. Please see this commit
for details:

https://github.com/torvalds/linux/commit/2b48e113866a6735de3a99531183afb6217c2a60

By making use of this you can probably get rid of venus_enc_state
entirely. Also this generic implementation should take care of corner
cases that this patch does not address (like streaming off while a
drain is in progress).

>
> Signed-off-by: Dikshita Agarwal <dikshita@xxxxxxxxxxxxxx>
> ---
> drivers/media/platform/qcom/venus/core.h | 9 +++++
> drivers/media/platform/qcom/venus/venc.c | 64 +++++++++++++++++++++++++++++++-
> 2 files changed, 72 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
> index e30eeaf..5c46936 100644
> --- a/drivers/media/platform/qcom/venus/core.h
> +++ b/drivers/media/platform/qcom/venus/core.h
> @@ -276,6 +276,14 @@ enum venus_dec_state {
> VENUS_DEC_STATE_DRC = 7,
> };
>
> +enum venus_enc_state {
> + VENUS_ENC_STATE_DEINIT = 0,
> + VENUS_ENC_STATE_INIT = 1,
> + VENUS_ENC_STATE_ENCODING = 2,
> + VENUS_ENC_STATE_STOPPED = 3,
> + VENUS_ENC_STATE_DRAIN = 4,
> +};
> +
> struct venus_ts_metadata {
> bool used;
> u64 ts_ns;
> @@ -367,6 +375,7 @@ struct venus_inst {
> u8 quantization;
> u8 xfer_func;
> enum venus_dec_state codec_state;
> + enum venus_enc_state enc_state;
> wait_queue_head_t reconf_wait;
> unsigned int subscriptions;
> int buf_count;
> diff --git a/drivers/media/platform/qcom/venus/venc.c b/drivers/media/platform/qcom/venus/venc.c
> index f7fb6e3..c6143b0 100644
> --- a/drivers/media/platform/qcom/venus/venc.c
> +++ b/drivers/media/platform/qcom/venus/venc.c
> @@ -498,6 +498,46 @@ static int venc_enum_frameintervals(struct file *file, void *fh,
> return 0;
> }
>
> +static int
> +venc_encoder_cmd(struct file *file, void *fh, struct v4l2_encoder_cmd *cmd)
> +{
> + struct venus_inst *inst = to_inst(file);
> + struct hfi_frame_data fdata = {0};
> + int ret = 0;
> +
> + ret = v4l2_m2m_ioctl_try_encoder_cmd(file, fh, cmd);
> + if (ret)
> + return ret;
> +
> + mutex_lock(&inst->lock);
> +
> + if (cmd->cmd == V4L2_ENC_CMD_STOP &&
> + inst->enc_state == VENUS_ENC_STATE_ENCODING) {
> + /*
> + * Implement V4L2_ENC_CMD_STOP by enqueue an empty buffer on
> + * encoder 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 = 0xdeadb000;
> +
> + ret = hfi_session_process_buf(inst, &fdata);
> +
> + inst->enc_state = VENUS_ENC_STATE_DRAIN;
> + } else if (cmd->cmd == V4L2_ENC_CMD_START &&
> + inst->enc_state == VENUS_ENC_STATE_STOPPED) {
> + vb2_clear_last_buffer_dequeued(&inst->fh.m2m_ctx->cap_q_ctx.q);
> + inst->enc_state = VENUS_ENC_STATE_ENCODING;
> + }
> +
> +unlock:
> + mutex_unlock(&inst->lock);
> + return ret;
> +}
> +
> static const struct v4l2_ioctl_ops venc_ioctl_ops = {
> .vidioc_querycap = venc_querycap,
> .vidioc_enum_fmt_vid_cap = venc_enum_fmt,
> @@ -525,6 +565,7 @@ static int venc_enum_frameintervals(struct file *file, void *fh,
> .vidioc_enum_frameintervals = venc_enum_frameintervals,
> .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
> .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> + .vidioc_encoder_cmd = venc_encoder_cmd,
> };
>
> static int venc_set_properties(struct venus_inst *inst)
> @@ -884,6 +925,8 @@ static int venc_start_streaming(struct vb2_queue *q, unsigned int count)
> if (ret)
> goto deinit_sess;
>
> + inst->enc_state = VENUS_ENC_STATE_ENCODING;
> +
> mutex_unlock(&inst->lock);
>
> return 0;
> @@ -903,8 +946,19 @@ static int venc_start_streaming(struct vb2_queue *q, unsigned int count)
> static void venc_vb2_buf_queue(struct vb2_buffer *vb)
> {
> struct venus_inst *inst = vb2_get_drv_priv(vb->vb2_queue);
> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>
> mutex_lock(&inst->lock);
> +
> + if (inst->enc_state == VENUS_ENC_STATE_STOPPED) {
> + vbuf->sequence = inst->sequence_cap++;
> + vbuf->field = V4L2_FIELD_NONE;
> + vb2_set_plane_payload(vb, 0, 0);
> + v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_DONE);
> + mutex_unlock(&inst->lock);
> + return;
> + }
> +
> venus_helper_vb2_buf_queue(vb);
> mutex_unlock(&inst->lock);
> }
> @@ -943,6 +997,11 @@ static void venc_buf_done(struct venus_inst *inst, unsigned int buf_type,
> vb->planes[0].data_offset = data_offset;
> vb->timestamp = timestamp_us * NSEC_PER_USEC;
> vbuf->sequence = inst->sequence_cap++;
> +
> + if ((vbuf->flags & V4L2_BUF_FLAG_LAST) &&
> + inst->enc_state == VENUS_ENC_STATE_DRAIN) {
> + inst->enc_state = VENUS_ENC_STATE_STOPPED;
> + }
> } else {
> vbuf->sequence = inst->sequence_out++;
> }
> @@ -1041,6 +1100,9 @@ static int venc_open(struct file *file)
> inst->clk_data.core_id = VIDC_CORE_ID_DEFAULT;
> inst->core_acquired = false;
>
> + if (inst->enc_state == VENUS_ENC_STATE_DEINIT)
> + inst->enc_state = VENUS_ENC_STATE_INIT;
> +
> venus_helper_init_instance(inst);
>
> ret = pm_runtime_get_sync(core->dev_enc);
> @@ -1105,7 +1167,7 @@ static int venc_close(struct file *file)
> mutex_destroy(&inst->lock);
> v4l2_fh_del(&inst->fh);
> v4l2_fh_exit(&inst->fh);
> -
> + inst->enc_state = VENUS_ENC_STATE_DEINIT;
> pm_runtime_put_sync(inst->core->dev_enc);
>
> kfree(inst);
> --
> 1.9.1
>