Re: [PATCH] media: v4l2-mem2mem: allow device run without buf

[Nicolas Dufresne <nicolas.dufresne@collabora.com>]

Le mercredi 23 novembre 2022 à 17:24 +0800, Hsia-Jun Li a écrit :
> From: Randy Li <ayaka@soulik.info>
> 
> For the decoder supports Dynamic Resolution Change,
> we don't need to allocate any CAPTURE or graphics buffer
> for them at inital CAPTURE setup step.
> 
> We need to make the device run or we can't get those
> metadata.

Nack: This is not how it works. I know the m2m framework make it difficult, but
it is expected that the driver have a special state for OUTPUT streamon (before
capture streamon). Please have a look at other drivers.

Nicolas

> 
> Signed-off-by: Randy Li <ayaka@soulik.info>
> ---
>  drivers/media/v4l2-core/v4l2-mem2mem.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
> index be7fde1ed3ea..cd56d60fad9d 100644
> --- a/drivers/media/v4l2-core/v4l2-mem2mem.c
> +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
> @@ -301,8 +301,9 @@ static void __v4l2_m2m_try_queue(struct v4l2_m2m_dev *m2m_dev,
>  
>  	dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
>  
> -	if (!m2m_ctx->out_q_ctx.q.streaming
> -	    || !m2m_ctx->cap_q_ctx.q.streaming) {
> +	if (!(m2m_ctx->out_q_ctx.q.streaming || m2m_ctx->out_q_ctx.buffered)
> +	    || !(m2m_ctx->cap_q_ctx.q.streaming
> +		 || m2m_ctx->cap_q_ctx.buffered)) {
>  		dprintk("Streaming needs to be on for both queues\n");
>  		return;
>  	}