[Sound-open-firmware] [PATCH 2/2] Disable checking half full of local DMA trace buffer when trace_work is running.

[yan.wang at linux.intel.com]

From: Yan Wang <yan.wang at linux.intel.com>

If DMA trace copying is running, it is unnecessary to checking half full
local DMA trace buffer.
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;
 	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 */
-- 
2.7.4