[Sound-open-firmware] [PATCH v2 2/2] Do not check trace buffer fullness while a

[Liam Girdwood]

On Tue, 2017-12-05 at 15:09 +0800, yan.wang at linux.intel.com wrote:
> From: Yan Wang <yan.wang at linux.intel.com>
> 
> The purpose of checking half fullness is sending trace data as soon
> as 
> possible. It will avoid local DMA trace buffer full and unsent trace
> data 
> overwritten.
> If DMA trace copying is running currently, it is unnecessary to
> checking 
> half fullness local DMA trace buffer.
> 
> The following is implementation details:
> 1. Add one flag in DMA trace data strcuture.
> 2. Set/unset this flag in trace_work() callback.
> 3. Add checking for this flag in dtrace_event().
> 
> Signed-off-by: Yan Wang <yan.wang at linux.intel.com>
> ---
>  src/include/reef/dma-trace.h |  1 +
>  src/lib/dma-trace.c          | 17 +++++++++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/src/include/reef/dma-trace.h b/src/include/reef/dma-
> trace.h
> index 641a4dc..21824f3 100644
> --- a/src/include/reef/dma-trace.h
> +++ b/src/include/reef/dma-trace.h
> @@ -60,6 +60,7 @@ struct dma_trace_data {
>  	uint32_t host_size;
>  	struct work dmat_work;
>  	uint32_t enabled;
> +	uint32_t dmat_work_flag;

Best to rename this as copy_in_progress.

>  	spinlock_t lock;
>  };
>  
> diff --git a/src/lib/dma-trace.c b/src/lib/dma-trace.c
> index 763e955..9dfe7c7 100644
> --- a/src/lib/dma-trace.c
> +++ b/src/lib/dma-trace.c
> @@ -56,6 +56,9 @@ static uint64_t trace_work(void *data, uint64_t
> delay)
>  	if (avail == 0)
>  		return DMA_TRACE_US;
>  
> +	/* DMA trace copying is working */
> +	d->dmat_work_flag = 1;
> +
>  	/* make sure we dont write more than buffer */
>  	if (avail > DMA_TRACE_LOCAL_SIZE)
>  		avail = DMA_TRACE_LOCAL_SIZE;
> @@ -100,7 +103,12 @@ static uint64_t trace_work(void *data, uint64_t
> delay)
>  
>  out:
>  	spin_lock_irq(&d->lock, flags);
> +
>  	buffer->avail -= size;
> +
> +	/* DMA trace copying is done */
> +	d->dmat_work_flag = 0;
> +
>  	spin_unlock_irq(&d->lock, flags);
>  
>  	/* reschedule the trace copying work */
> @@ -138,6 +146,7 @@ int dma_trace_init(struct dma_trace_data *d)
>  	buffer->avail = 0;
>  	d->host_offset = 0;
>  	d->enabled = 0;
> +	d->dmat_work_flag = 0;
>  
>  	list_init(&d->config.elem_list);
>  	work_init(&d->dmat_work, trace_work, d, WORK_ASYNC);
> @@ -226,6 +235,14 @@ void dtrace_event(const char *e, uint32_t
> length)
>  
>  	spin_lock_irq(&trace_data->lock, flags);
>  	dtrace_add_event(e, length);
> +
> +	/* if DMA trace copying is working */
> +	/* don't check if local buffer is half full */
> +	if (trace_data->dmat_work_flag) {
> +		spin_unlock_irq(&trace_data->lock, flags);
> +		return;
> +	}
> +
>  	spin_unlock_irq(&trace_data->lock, flags);
>  
>  	/* schedule copy now if buffer > 50% full */
---------------------------------------------------------------------
Intel Corporation (UK) Limited
Registered No. 1134945 (England)
Registered Office: Pipers Way, Swindon SN3 1RJ
VAT No: 860 2173 47

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.