Re: [PATCH 10/10] venus: dec: make decoder compliant with stateful codec API

[Hans Verkuil <hverkuil@xs4all.nl>]

On 2/15/19 5:27 PM, Nicolas Dufresne wrote:
> Le vendredi 15 février 2019 à 14:44 +0100, Hans Verkuil a écrit :
>> Hi Stanimir,
>>
>> I never paid much attention to this patch series since others were busy
>> discussing it and I had a lot of other things on my plate, but then I heard
>> that this patch made G_FMT blocking.
>>
>> That's a no-go. Apparently s5p-mfc does that as well, and that's against
>> the V4L2 spec as well (clearly I never realized that at the time).
>>
>> So, just to make it unambiguous:
>>
>> Nacked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> 
> Careful if you pull out this code from S5P MFC though, since you'll
> break userspace and we don't like when kernel do that. As we discussed,
> Philipp in CODA came up with a clever workaround, so if one have the
> idea of touching MFC, please make sure to do so correctly.

I'm not pulling any code out of S5P MFC, I just want to prevent propagating
a bad idea into other drivers.

Regards,

	Hans

> 
>>
>> Now, I plan to work on adding stateful codec checks to v4l2-compliance.
>> I had hoped to do some of that already, but didn't manage to find time
>> this week. I hope to have something decent in 2-3 weeks from now.
>>
>> So I would wait with making this driver compliant until I have written
>> the tests.
>>
>> Initially I'll test this with vicodec, but the next phase would be to
>> make it work with e.g. a venus codec. I might contact you for help
>> when I start work on that.
>>
>> Regards,
>>
>> 	Hans
>>
>> On 1/17/19 5:20 PM, Stanimir Varbanov wrote:
>>> This refactored code for start/stop streaming vb2 operations and
>>> adds a state machine handling similar to the one in stateful codec
>>> API documentation. One major change is that now the HFI session is
>>> started on STREAMON(OUTPUT) and stopped on REQBUF(OUTPUT,count=0),
>>> during that time streamoff(cap,out) just flush buffers but doesn't
>>> stop the session. The other major change is that now the capture
>>> and output queues are completely separated.
>>>
>>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
>>> ---
>>>  drivers/media/platform/qcom/venus/core.h    |  20 +-
>>>  drivers/media/platform/qcom/venus/helpers.c |  23 +-
>>>  drivers/media/platform/qcom/venus/helpers.h |   5 +
>>>  drivers/media/platform/qcom/venus/vdec.c    | 449 ++++++++++++++++----
>>>  4 files changed, 389 insertions(+), 108 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
>>> index 79c7e816c706..5a133c203455 100644
>>> --- a/drivers/media/platform/qcom/venus/core.h
>>> +++ b/drivers/media/platform/qcom/venus/core.h
>>> @@ -218,6 +218,15 @@ struct venus_buffer {
>>>  
>>>  #define to_venus_buffer(ptr)	container_of(ptr, struct venus_buffer, vb)
>>>  
>>> +#define DEC_STATE_UNINIT		0
>>> +#define DEC_STATE_INIT			1
>>> +#define DEC_STATE_CAPTURE_SETUP		2
>>> +#define DEC_STATE_STOPPED		3
>>> +#define DEC_STATE_SEEK			4
>>> +#define DEC_STATE_DRAIN			5
>>> +#define DEC_STATE_DECODING		6
>>> +#define DEC_STATE_DRC			7
>>> +
>>>  /**
>>>   * struct venus_inst - holds per instance paramerters
>>>   *
>>> @@ -241,6 +250,10 @@ struct venus_buffer {
>>>   * @colorspace:	current color space
>>>   * @quantization:	current quantization
>>>   * @xfer_func:	current xfer function
>>> + * @codec_state:	current codec API state (see DEC/ENC_STATE_)
>>> + * @reconf_wait:	wait queue for resolution change event
>>> + * @ten_bits:		does new stream is 10bits depth
>>> + * @buf_count:		used to count number number of buffers (reqbuf(0))
>>>   * @fps:		holds current FPS
>>>   * @timeperframe:	holds current time per frame structure
>>>   * @fmt_out:	a reference to output format structure
>>> @@ -255,8 +268,6 @@ struct venus_buffer {
>>>   * @opb_buftype:	output picture buffer type
>>>   * @opb_fmt:		output picture buffer raw format
>>>   * @reconfig:	a flag raised by decoder when the stream resolution changed
>>> - * @reconfig_width:	holds the new width
>>> - * @reconfig_height:	holds the new height
>>>   * @hfi_codec:		current codec for this instance in HFI space
>>>   * @sequence_cap:	a sequence counter for capture queue
>>>   * @sequence_out:	a sequence counter for output queue
>>> @@ -296,6 +307,9 @@ struct venus_inst {
>>>  	u8 ycbcr_enc;
>>>  	u8 quantization;
>>>  	u8 xfer_func;
>>> +	unsigned int codec_state;
>>> +	wait_queue_head_t reconf_wait;
>>> +	int buf_count;
>>>  	u64 fps;
>>>  	struct v4l2_fract timeperframe;
>>>  	const struct venus_format *fmt_out;
>>> @@ -310,8 +324,6 @@ struct venus_inst {
>>>  	u32 opb_buftype;
>>>  	u32 opb_fmt;
>>>  	bool reconfig;
>>> -	u32 reconfig_width;
>>> -	u32 reconfig_height;
>>>  	u32 hfi_codec;
>>>  	u32 sequence_cap;
>>>  	u32 sequence_out;
>>> diff --git a/drivers/media/platform/qcom/venus/helpers.c b/drivers/media/platform/qcom/venus/helpers.c
>>> index 637ce7b82d94..25d8cceccae4 100644
>>> --- a/drivers/media/platform/qcom/venus/helpers.c
>>> +++ b/drivers/media/platform/qcom/venus/helpers.c
>>> @@ -1030,16 +1030,15 @@ void venus_helper_vb2_buf_queue(struct vb2_buffer *vb)
>>>  
>>>  	v4l2_m2m_buf_queue(m2m_ctx, vbuf);
>>>  
>>> -	if (!(inst->streamon_out & inst->streamon_cap))
>>> -		goto unlock;
>>> -
>>> -	ret = is_buf_refed(inst, vbuf);
>>> -	if (ret)
>>> -		goto unlock;
>>> +	if (IS_OUT(vb->vb2_queue, inst) || IS_CAP(vb->vb2_queue, inst)) {
>>> +		ret = is_buf_refed(inst, vbuf);
>>> +		if (ret)
>>> +			goto unlock;
>>>  
>>> -	ret = session_process_buf(inst, vbuf);
>>> -	if (ret)
>>> -		return_buf_error(inst, vbuf);
>>> +		ret = session_process_buf(inst, vbuf);
>>> +		if (ret)
>>> +			return_buf_error(inst, vbuf);
>>> +	}
>>>  
>>>  unlock:
>>>  	mutex_unlock(&inst->lock);
>>> @@ -1155,14 +1154,8 @@ int venus_helper_vb2_start_streaming(struct venus_inst *inst)
>>>  	if (ret)
>>>  		goto err_unload_res;
>>>  
>>> -	ret = venus_helper_queue_dpb_bufs(inst);
>>> -	if (ret)
>>> -		goto err_session_stop;
>>> -
>>>  	return 0;
>>>  
>>> -err_session_stop:
>>> -	hfi_session_stop(inst);
>>>  err_unload_res:
>>>  	hfi_session_unload_res(inst);
>>>  err_unreg_bufs:
>>> diff --git a/drivers/media/platform/qcom/venus/helpers.h b/drivers/media/platform/qcom/venus/helpers.h
>>> index 2ec1c1a8b416..3b46139b5ee1 100644
>>> --- a/drivers/media/platform/qcom/venus/helpers.h
>>> +++ b/drivers/media/platform/qcom/venus/helpers.h
>>> @@ -17,6 +17,11 @@
>>>  
>>>  #include <media/videobuf2-v4l2.h>
>>>  
>>> +#define IS_OUT(q, inst) (inst->streamon_out &&	\
>>> +		q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
>>> +#define IS_CAP(q, inst) (inst->streamon_cap &&	\
>>> +		q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
>>> +
>>>  struct venus_inst;
>>>  struct venus_core;
>>>  
>>> diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c
>>> index 7a9370df7515..306e0f7d3337 100644
>>> --- a/drivers/media/platform/qcom/venus/vdec.c
>>> +++ b/drivers/media/platform/qcom/venus/vdec.c
>>> @@ -201,28 +201,18 @@ static int vdec_g_fmt(struct file *file, void *fh, struct v4l2_format *f)
>>>  	struct venus_inst *inst = to_inst(file);
>>>  	const struct venus_format *fmt = NULL;
>>>  	struct v4l2_pix_format_mplane *pixmp = &f->fmt.pix_mp;
>>> +	int ret;
>>>  
>>>  	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
>>>  		fmt = inst->fmt_cap;
>>>  	else if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
>>>  		fmt = inst->fmt_out;
>>>  
>>> -	if (inst->reconfig) {
>>> -		struct v4l2_format format = {};
>>> -
>>> -		inst->out_width = inst->reconfig_width;
>>> -		inst->out_height = inst->reconfig_height;
>>> -		inst->reconfig = false;
>>> -
>>> -		format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
>>> -		format.fmt.pix_mp.pixelformat = inst->fmt_cap->pixfmt;
>>> -		format.fmt.pix_mp.width = inst->out_width;
>>> -		format.fmt.pix_mp.height = inst->out_height;
>>> -
>>> -		vdec_try_fmt_common(inst, &format);
>>> -
>>> -		inst->width = format.fmt.pix_mp.width;
>>> -		inst->height = format.fmt.pix_mp.height;
>>> +	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
>>> +		ret = wait_event_timeout(inst->reconf_wait, inst->reconfig,
>>> +					 msecs_to_jiffies(100));
>>> +		if (!ret)
>>> +			return -EINVAL;
>>>  	}
>>>  
>>>  	pixmp->pixelformat = fmt->pixfmt;
>>> @@ -457,6 +447,10 @@ vdec_try_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd *cmd)
>>>  		if (cmd->flags & V4L2_DEC_CMD_STOP_TO_BLACK)
>>>  			return -EINVAL;
>>>  		break;
>>> +	case V4L2_DEC_CMD_START:
>>> +		if (cmd->flags & V4L2_DEC_CMD_START_MUTE_AUDIO)
>>> +			return -EINVAL;
>>> +		break;
>>>  	default:
>>>  		return -EINVAL;
>>>  	}
>>> @@ -477,18 +471,23 @@ vdec_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd *cmd)
>>>  
>>>  	mutex_lock(&inst->lock);
>>>  
>>> -	/*
>>> -	 * 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;
>>> +	if (cmd->cmd == V4L2_DEC_CMD_STOP) {
>>> +		/*
>>> +		 * 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;
>>> +		fdata.buffer_type = HFI_BUFFER_INPUT;
>>> +		fdata.flags |= HFI_BUFFERFLAG_EOS;
>>> +		fdata.device_addr = 0xdeadb000;
>>>  
>>> -	ret = hfi_session_process_buf(inst, &fdata);
>>> +		ret = hfi_session_process_buf(inst, &fdata);
>>> +
>>> +		if (!ret && inst->codec_state == DEC_STATE_DECODING)
>>> +			inst->codec_state = DEC_STATE_DRAIN;
>>> +	}
>>>  
>>>  unlock:
>>>  	mutex_unlock(&inst->lock);
>>> @@ -649,20 +648,18 @@ static int vdec_output_conf(struct venus_inst *inst)
>>>  	return 0;
>>>  }
>>>  
>>> -static int vdec_init_session(struct venus_inst *inst)
>>> +static int vdec_session_init(struct venus_inst *inst)
>>>  {
>>>  	int ret;
>>>  
>>>  	ret = hfi_session_init(inst, inst->fmt_out->pixfmt);
>>> -	if (ret)
>>> +	if (ret == -EINVAL)
>>> +		return 0;
>>> +	else if (ret)
>>>  		return ret;
>>>  
>>> -	ret = venus_helper_set_input_resolution(inst, inst->out_width,
>>> -						inst->out_height);
>>> -	if (ret)
>>> -		goto deinit;
>>> -
>>> -	ret = venus_helper_set_color_format(inst, inst->fmt_cap->pixfmt);
>>> +	ret = venus_helper_set_input_resolution(inst, frame_width_min(inst),
>>> +						frame_height_min(inst));
>>>  	if (ret)
>>>  		goto deinit;
>>>  
>>> @@ -681,26 +678,19 @@ static int vdec_num_buffers(struct venus_inst *inst, unsigned int *in_num,
>>>  
>>>  	*in_num = *out_num = 0;
>>>  
>>> -	ret = vdec_init_session(inst);
>>> -	if (ret)
>>> -		return ret;
>>> -
>>>  	ret = venus_helper_get_bufreq(inst, HFI_BUFFER_INPUT, &bufreq);
>>>  	if (ret)
>>> -		goto deinit;
>>> +		return ret;
>>>  
>>>  	*in_num = HFI_BUFREQ_COUNT_MIN(&bufreq, ver);
>>>  
>>>  	ret = venus_helper_get_bufreq(inst, HFI_BUFFER_OUTPUT, &bufreq);
>>>  	if (ret)
>>> -		goto deinit;
>>> +		return ret;
>>>  
>>>  	*out_num = HFI_BUFREQ_COUNT_MIN(&bufreq, ver);
>>>  
>>> -deinit:
>>> -	hfi_session_deinit(inst);
>>> -
>>> -	return ret;
>>> +	return 0;
>>>  }
>>>  
>>>  static int vdec_queue_setup(struct vb2_queue *q,
>>> @@ -733,6 +723,10 @@ static int vdec_queue_setup(struct vb2_queue *q,
>>>  		return 0;
>>>  	}
>>>  
>>> +	ret = vdec_session_init(inst);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>>  	ret = vdec_num_buffers(inst, &in_num, &out_num);
>>>  	if (ret)
>>>  		return ret;
>>> @@ -758,6 +752,11 @@ static int vdec_queue_setup(struct vb2_queue *q,
>>>  		inst->output_buf_size = sizes[0];
>>>  		*num_buffers = max(*num_buffers, out_num);
>>>  		inst->num_output_bufs = *num_buffers;
>>> +
>>> +		mutex_lock(&inst->lock);
>>> +		if (inst->codec_state == DEC_STATE_CAPTURE_SETUP)
>>> +			inst->codec_state = DEC_STATE_STOPPED;
>>> +		mutex_unlock(&inst->lock);
>>>  		break;
>>>  	default:
>>>  		ret = -EINVAL;
>>> @@ -794,80 +793,298 @@ static int vdec_verify_conf(struct venus_inst *inst)
>>>  	return 0;
>>>  }
>>>  
>>> -static int vdec_start_streaming(struct vb2_queue *q, unsigned int count)
>>> +static int vdec_start_capture(struct venus_inst *inst)
>>>  {
>>> -	struct venus_inst *inst = vb2_get_drv_priv(q);
>>>  	int ret;
>>>  
>>> -	mutex_lock(&inst->lock);
>>> +	if (!inst->streamon_out)
>>> +		return -EINVAL;
>>>  
>>> -	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
>>> -		inst->streamon_out = 1;
>>> -	else
>>> -		inst->streamon_cap = 1;
>>> +	if (inst->codec_state == DEC_STATE_DECODING) {
>>> +		if (inst->reconfig)
>>> +			goto reconfigure;
>>>  
>>> -	if (!(inst->streamon_out & inst->streamon_cap)) {
>>> -		mutex_unlock(&inst->lock);
>>> +		venus_helper_queue_dpb_bufs(inst);
>>> +		venus_helper_process_initial_cap_bufs(inst);
>>> +		inst->streamon_cap = 1;
>>>  		return 0;
>>>  	}
>>>  
>>> -	venus_helper_init_instance(inst);
>>> +	if (inst->codec_state != DEC_STATE_STOPPED)
>>> +		return -EINVAL;
>>>  
>>> -	inst->reconfig = false;
>>> -	inst->sequence_cap = 0;
>>> -	inst->sequence_out = 0;
>>> +reconfigure:
>>> +	ret = hfi_session_flush(inst, HFI_FLUSH_OUTPUT);
>>> +	if (ret)
>>> +		return ret;
>>>  
>>> -	ret = vdec_init_session(inst);
>>> +	ret = vdec_output_conf(inst);
>>>  	if (ret)
>>> -		goto bufs_done;
>>> +		return ret;
>>> +
>>> +	ret = venus_helper_set_num_bufs(inst, inst->num_input_bufs,
>>> +					VB2_MAX_FRAME, VB2_MAX_FRAME);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	ret = venus_helper_intbufs_realloc(inst);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	ret = venus_helper_alloc_dpb_bufs(inst);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	ret = venus_helper_queue_dpb_bufs(inst);
>>> +	if (ret)
>>> +		goto free_dpb_bufs;
>>> +
>>> +	ret = venus_helper_process_initial_cap_bufs(inst);
>>> +	if (ret)
>>> +		goto free_dpb_bufs;
>>> +
>>> +	venus_helper_load_scale_clocks(inst->core);
>>> +
>>> +	ret = hfi_session_continue(inst);
>>> +	if (ret)
>>> +		goto free_dpb_bufs;
>>> +
>>> +	inst->codec_state = DEC_STATE_DECODING;
>>> +
>>> +	inst->streamon_cap = 1;
>>> +	inst->sequence_cap = 0;
>>> +	inst->reconfig = false;
>>> +
>>> +	return 0;
>>> +
>>> +free_dpb_bufs:
>>> +	venus_helper_free_dpb_bufs(inst);
>>> +err:
>>> +	return ret;
>>> +}
>>> +
>>> +static int vdec_start_output(struct venus_inst *inst)
>>> +{
>>> +	int ret;
>>> +
>>> +	if (inst->codec_state == DEC_STATE_SEEK) {
>>> +		ret = venus_helper_process_initial_out_bufs(inst);
>>> +		inst->codec_state = DEC_STATE_DECODING;
>>> +		goto done;
>>> +	}
>>> +
>>> +	if (inst->codec_state == DEC_STATE_INIT ||
>>> +	    inst->codec_state == DEC_STATE_CAPTURE_SETUP) {
>>> +		ret = venus_helper_process_initial_out_bufs(inst);
>>> +		goto done;
>>> +	}
>>> +
>>> +	if (inst->codec_state != DEC_STATE_UNINIT)
>>> +		return -EINVAL;
>>> +
>>> +	venus_helper_init_instance(inst);
>>> +	inst->sequence_out = 0;
>>> +	inst->reconfig = false;
>>>  
>>>  	ret = vdec_set_properties(inst);
>>>  	if (ret)
>>> -		goto deinit_sess;
>>> +		return ret;
>>>  
>>>  	ret = vdec_output_conf(inst);
>>>  	if (ret)
>>> -		goto deinit_sess;
>>> +		return ret;
>>>  
>>>  	ret = vdec_verify_conf(inst);
>>>  	if (ret)
>>> -		goto deinit_sess;
>>> +		return ret;
>>>  
>>>  	ret = venus_helper_set_num_bufs(inst, inst->num_input_bufs,
>>>  					VB2_MAX_FRAME, VB2_MAX_FRAME);
>>>  	if (ret)
>>> -		goto deinit_sess;
>>> +		return ret;
>>>  
>>> -	ret = venus_helper_alloc_dpb_bufs(inst);
>>> +	ret = venus_helper_vb2_start_streaming(inst);
>>>  	if (ret)
>>> -		goto deinit_sess;
>>> +		return ret;
>>>  
>>> -	ret = venus_helper_vb2_start_streaming(inst);
>>> +	ret = venus_helper_process_initial_out_bufs(inst);
>>>  	if (ret)
>>> -		goto deinit_sess;
>>> +		return ret;
>>>  
>>> -	mutex_unlock(&inst->lock);
>>> +	inst->codec_state = DEC_STATE_INIT;
>>> +
>>> +done:
>>> +	inst->streamon_out = 1;
>>> +	return ret;
>>> +}
>>> +
>>> +static int vdec_start_streaming(struct vb2_queue *q, unsigned int count)
>>> +{
>>> +	struct venus_inst *inst = vb2_get_drv_priv(q);
>>> +	int ret;
>>> +
>>> +	mutex_lock(&inst->lock);
>>> +
>>> +	if (q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
>>> +		ret = vdec_start_capture(inst);
>>> +	else
>>> +		ret = vdec_start_output(inst);
>>>  
>>> +	if (ret)
>>> +		goto error;
>>> +
>>> +	mutex_unlock(&inst->lock);
>>>  	return 0;
>>>  
>>> -deinit_sess:
>>> -	hfi_session_deinit(inst);
>>> -bufs_done:
>>> +error:
>>>  	venus_helper_buffers_done(inst, VB2_BUF_STATE_QUEUED);
>>> +	mutex_unlock(&inst->lock);
>>> +	return ret;
>>> +}
>>> +
>>> +static void vdec_dst_buffers_done(struct venus_inst *inst,
>>> +				  enum vb2_buffer_state state)
>>> +{
>>> +	struct vb2_v4l2_buffer *buf;
>>> +
>>> +	while ((buf = v4l2_m2m_dst_buf_remove(inst->m2m_ctx)))
>>> +		v4l2_m2m_buf_done(buf, state);
>>> +}
>>> +
>>> +static int vdec_stop_capture(struct venus_inst *inst)
>>> +{
>>> +	int ret = 0;
>>> +
>>> +	switch (inst->codec_state) {
>>> +	case DEC_STATE_DECODING:
>>> +		ret = hfi_session_flush(inst, HFI_FLUSH_ALL);
>>> +		vdec_dst_buffers_done(inst, VB2_BUF_STATE_ERROR);
>>> +		inst->codec_state = DEC_STATE_STOPPED;
>>> +		break;
>>> +	case DEC_STATE_DRAIN:
>>> +		vdec_dst_buffers_done(inst, VB2_BUF_STATE_ERROR);
>>> +		inst->codec_state = DEC_STATE_STOPPED;
>>> +		break;
>>> +	case DEC_STATE_DRC:
>>> +		ret = hfi_session_flush(inst, HFI_FLUSH_OUTPUT);
>>> +		vdec_dst_buffers_done(inst, VB2_BUF_STATE_ERROR);
>>> +		inst->codec_state = DEC_STATE_CAPTURE_SETUP;
>>> +		INIT_LIST_HEAD(&inst->registeredbufs);
>>> +		venus_helper_free_dpb_bufs(inst);
>>> +		break;
>>> +	default:
>>> +		return 0;
>>> +	}
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static int vdec_stop_output(struct venus_inst *inst)
>>> +{
>>> +	int ret = 0;
>>> +
>>> +	switch (inst->codec_state) {
>>> +	case DEC_STATE_DECODING:
>>> +	case DEC_STATE_DRAIN:
>>> +	case DEC_STATE_STOPPED:
>>> +		ret = hfi_session_flush(inst, HFI_FLUSH_ALL);
>>> +		inst->codec_state = DEC_STATE_SEEK;
>>> +		break;
>>> +	case DEC_STATE_INIT:
>>> +	case DEC_STATE_CAPTURE_SETUP:
>>> +		ret = hfi_session_flush(inst, HFI_FLUSH_INPUT);
>>> +		break;
>>> +	default:
>>> +		break;
>>> +	}
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static void vdec_stop_streaming(struct vb2_queue *q)
>>> +{
>>> +	struct venus_inst *inst = vb2_get_drv_priv(q);
>>> +	int ret = -EINVAL;
>>> +
>>> +	mutex_lock(&inst->lock);
>>> +
>>> +	if (IS_CAP(q, inst))
>>> +		ret = vdec_stop_capture(inst);
>>> +	else if (IS_OUT(q, inst))
>>> +		ret = vdec_stop_output(inst);
>>> +
>>> +	venus_helper_buffers_done(inst, VB2_BUF_STATE_ERROR);
>>> +
>>> +	if (ret)
>>> +		goto unlock;
>>> +
>>>  	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
>>>  		inst->streamon_out = 0;
>>>  	else
>>>  		inst->streamon_cap = 0;
>>> +
>>> +unlock:
>>>  	mutex_unlock(&inst->lock);
>>> -	return ret;
>>> +}
>>> +
>>> +static void vdec_session_release(struct venus_inst *inst)
>>> +{
>>> +	struct venus_core *core = inst->core;
>>> +	int ret, abort = 0;
>>> +
>>> +	mutex_lock(&inst->lock);
>>> +
>>> +	inst->codec_state = DEC_STATE_UNINIT;
>>> +
>>> +	ret = hfi_session_stop(inst);
>>> +	abort = (ret && ret != -EINVAL) ? 1 : 0;
>>> +	ret = hfi_session_unload_res(inst);
>>> +	abort = (ret && ret != -EINVAL) ? 1 : 0;
>>> +	ret = venus_helper_unregister_bufs(inst);
>>> +	abort = (ret && ret != -EINVAL) ? 1 : 0;
>>> +	ret = venus_helper_intbufs_free(inst);
>>> +	abort = (ret && ret != -EINVAL) ? 1 : 0;
>>> +	ret = hfi_session_deinit(inst);
>>> +	abort = (ret && ret != -EINVAL) ? 1 : 0;
>>> +
>>> +	if (inst->session_error || core->sys_error)
>>> +		abort = 1;
>>> +
>>> +	if (abort)
>>> +		hfi_session_abort(inst);
>>> +
>>> +	venus_helper_free_dpb_bufs(inst);
>>> +	venus_helper_load_scale_clocks(core);
>>> +	INIT_LIST_HEAD(&inst->registeredbufs);
>>> +
>>> +	mutex_unlock(&inst->lock);
>>> +}
>>> +
>>> +static int vdec_buf_init(struct vb2_buffer *vb)
>>> +{
>>> +	struct venus_inst *inst = vb2_get_drv_priv(vb->vb2_queue);
>>> +
>>> +	inst->buf_count++;
>>> +
>>> +	return venus_helper_vb2_buf_init(vb);
>>> +}
>>> +
>>> +static void vdec_buf_cleanup(struct vb2_buffer *vb)
>>> +{
>>> +	struct venus_inst *inst = vb2_get_drv_priv(vb->vb2_queue);
>>> +
>>> +	inst->buf_count--;
>>> +	if (!inst->buf_count)
>>> +		vdec_session_release(inst);
>>>  }
>>>  
>>>  static const struct vb2_ops vdec_vb2_ops = {
>>>  	.queue_setup = vdec_queue_setup,
>>> -	.buf_init = venus_helper_vb2_buf_init,
>>> +	.buf_init = vdec_buf_init,
>>> +	.buf_cleanup = vdec_buf_cleanup,
>>>  	.buf_prepare = venus_helper_vb2_buf_prepare,
>>>  	.start_streaming = vdec_start_streaming,
>>> -	.stop_streaming = venus_helper_vb2_stop_streaming,
>>> +	.stop_streaming = vdec_stop_streaming,
>>>  	.buf_queue = venus_helper_vb2_buf_queue,
>>>  };
>>>  
>>> @@ -891,6 +1108,7 @@ static void vdec_buf_done(struct venus_inst *inst, unsigned int buf_type,
>>>  
>>>  	vbuf->flags = flags;
>>>  	vbuf->field = V4L2_FIELD_NONE;
>>> +	vb = &vbuf->vb2_buf;
>>>  
>>>  	if (type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
>>>  		vb = &vbuf->vb2_buf;
>>> @@ -903,6 +1121,9 @@ static void vdec_buf_done(struct venus_inst *inst, unsigned int buf_type,
>>>  			const struct v4l2_event ev = { .type = V4L2_EVENT_EOS };
>>>  
>>>  			v4l2_event_queue_fh(&inst->fh, &ev);
>>> +
>>> +			if (inst->codec_state == DEC_STATE_DRAIN)
>>> +				inst->codec_state = DEC_STATE_STOPPED;
>>>  		}
>>>  	} else {
>>>  		vbuf->sequence = inst->sequence_out++;
>>> @@ -914,17 +1135,69 @@ static void vdec_buf_done(struct venus_inst *inst, unsigned int buf_type,
>>>  	if (hfi_flags & HFI_BUFFERFLAG_DATACORRUPT)
>>>  		state = VB2_BUF_STATE_ERROR;
>>>  
>>> +	if (hfi_flags & HFI_BUFFERFLAG_DROP_FRAME) {
>>> +		state = VB2_BUF_STATE_ERROR;
>>> +		vb2_set_plane_payload(vb, 0, 0);
>>> +		vb->timestamp = 0;
>>> +	}
>>> +
>>>  	v4l2_m2m_buf_done(vbuf, state);
>>>  }
>>>  
>>> +static void vdec_event_change(struct venus_inst *inst,
>>> +			      struct hfi_event_data *ev_data, bool sufficient)
>>> +{
>>> +	static const struct v4l2_event ev = {
>>> +		.type = V4L2_EVENT_SOURCE_CHANGE,
>>> +		.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION };
>>> +	struct device *dev = inst->core->dev_dec;
>>> +	struct v4l2_format format = {};
>>> +
>>> +	mutex_lock(&inst->lock);
>>> +
>>> +	format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
>>> +	format.fmt.pix_mp.pixelformat = inst->fmt_cap->pixfmt;
>>> +	format.fmt.pix_mp.width = ev_data->width;
>>> +	format.fmt.pix_mp.height = ev_data->height;
>>> +
>>> +	vdec_try_fmt_common(inst, &format);
>>> +
>>> +	inst->width = format.fmt.pix_mp.width;
>>> +	inst->height = format.fmt.pix_mp.height;
>>> +
>>> +	inst->out_width = ev_data->width;
>>> +	inst->out_height = ev_data->height;
>>> +
>>> +	dev_dbg(dev, "event %s sufficient resources (%ux%u)\n",
>>> +		sufficient ? "" : "not", ev_data->width, ev_data->height);
>>> +
>>> +	if (sufficient) {
>>> +		hfi_session_continue(inst);
>>> +	} else {
>>> +		switch (inst->codec_state) {
>>> +		case DEC_STATE_INIT:
>>> +			inst->codec_state = DEC_STATE_CAPTURE_SETUP;
>>> +			break;
>>> +		case DEC_STATE_DECODING:
>>> +			inst->codec_state = DEC_STATE_DRC;
>>> +			break;
>>> +		default:
>>> +			break;
>>> +		}
>>> +	}
>>> +
>>> +	inst->reconfig = true;
>>> +	v4l2_event_queue_fh(&inst->fh, &ev);
>>> +	wake_up(&inst->reconf_wait);
>>> +
>>> +	mutex_unlock(&inst->lock);
>>> +}
>>> +
>>>  static void vdec_event_notify(struct venus_inst *inst, u32 event,
>>>  			      struct hfi_event_data *data)
>>>  {
>>>  	struct venus_core *core = inst->core;
>>>  	struct device *dev = core->dev_dec;
>>> -	static const struct v4l2_event ev = {
>>> -		.type = V4L2_EVENT_SOURCE_CHANGE,
>>> -		.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION };
>>>  
>>>  	switch (event) {
>>>  	case EVT_SESSION_ERROR:
>>> @@ -934,18 +1207,10 @@ static void vdec_event_notify(struct venus_inst *inst, u32 event,
>>>  	case EVT_SYS_EVENT_CHANGE:
>>>  		switch (data->event_type) {
>>>  		case HFI_EVENT_DATA_SEQUENCE_CHANGED_SUFFICIENT_BUF_RESOURCES:
>>> -			hfi_session_continue(inst);
>>> -			dev_dbg(dev, "event sufficient resources\n");
>>> +			vdec_event_change(inst, data, true);
>>>  			break;
>>>  		case HFI_EVENT_DATA_SEQUENCE_CHANGED_INSUFFICIENT_BUF_RESOURCES:
>>> -			inst->reconfig_height = data->height;
>>> -			inst->reconfig_width = data->width;
>>> -			inst->reconfig = true;
>>> -
>>> -			v4l2_event_queue_fh(&inst->fh, &ev);
>>> -
>>> -			dev_dbg(dev, "event not sufficient resources (%ux%u)\n",
>>> -				data->width, data->height);
>>> +			vdec_event_change(inst, data, false);
>>>  			break;
>>>  		case HFI_EVENT_RELEASE_BUFFER_REFERENCE:
>>>  			venus_helper_release_buf_ref(inst, data->tag);
>>> @@ -978,8 +1243,12 @@ static void vdec_inst_init(struct venus_inst *inst)
>>>  	inst->hfi_codec = HFI_VIDEO_CODEC_H264;
>>>  }
>>>  
>>> +static void vdec_m2m_device_run(void *priv)
>>> +{
>>> +}
>>> +
>>>  static const struct v4l2_m2m_ops vdec_m2m_ops = {
>>> -	.device_run = venus_helper_m2m_device_run,
>>> +	.device_run = vdec_m2m_device_run,
>>>  	.job_abort = venus_helper_m2m_job_abort,
>>>  };
>>>  
>>> @@ -1041,7 +1310,9 @@ static int vdec_open(struct file *file)
>>>  	inst->core = core;
>>>  	inst->session_type = VIDC_SESSION_TYPE_DEC;
>>>  	inst->num_output_bufs = 1;
>>> -
>>> +	inst->codec_state = DEC_STATE_UNINIT;
>>> +	inst->buf_count = 0;
>>> +	init_waitqueue_head(&inst->reconf_wait);
>>>  	venus_helper_init_instance(inst);
>>>  
>>>  	ret = pm_runtime_get_sync(core->dev_dec);
>>>