[Sound-open-firmware] [PATCH 2/2] trace: dma: Help kernel and userspace detect missing trace messages.

[Liam Girdwood]

Add message count and overflow detection to the trace position output
so that kernel and userspace can detect the trace buffer has overflowed.

Signed-off-by: Liam Girdwood <liam.r.girdwood at linux.intel.com>
---
 src/include/reef/dma-trace.h | 2 ++
 src/include/uapi/ipc.h       | 2 ++
 src/ipc/intel-ipc.c          | 2 ++
 src/lib/dma-trace.c          | 9 ++++++++-
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/include/reef/dma-trace.h b/src/include/reef/dma-trace.h
index 4b17953..ab9c112 100644
--- a/src/include/reef/dma-trace.h
+++ b/src/include/reef/dma-trace.h
@@ -57,6 +57,8 @@ struct dma_trace_data {
 	struct dma_trace_buf dmatb;
 	struct dma_copy dc;
 	uint32_t host_offset;
+	uint32_t overflow;
+	uint32_t messages;
 	uint32_t host_size;
 	struct work dmat_work;
 	uint32_t enabled;
diff --git a/src/include/uapi/ipc.h b/src/include/uapi/ipc.h
index dc35035..7123c8e 100644
--- a/src/include/uapi/ipc.h
+++ b/src/include/uapi/ipc.h
@@ -816,6 +816,8 @@ struct sof_ipc_dma_trace_params {
 struct sof_ipc_dma_trace_posn {
 	struct sof_ipc_reply rhdr;
 	uint32_t host_offset;	/* Offset of DMA host buffer */
+	uint32_t overflow;	/* overflow bytes if any */
+	uint32_t messages;	/* total trace messages */
 }  __attribute__((packed));
 
 #endif
diff --git a/src/ipc/intel-ipc.c b/src/ipc/intel-ipc.c
index 5ddb1e3..5a98e1f 100644
--- a/src/ipc/intel-ipc.c
+++ b/src/ipc/intel-ipc.c
@@ -648,6 +648,8 @@ int ipc_dma_trace_send_position(void)
 
 	posn.rhdr.hdr.cmd =  SOF_IPC_GLB_TRACE_MSG | SOF_IPC_TRACE_DMA_POSITION;
 	posn.host_offset = _ipc->dmat.host_offset;
+	posn.overflow = _ipc->dmat.overflow;
+	posn.messages = _ipc->dmat.messages;
 	posn.rhdr.hdr.size = sizeof(posn);
 
 	return ipc_queue_host_message(_ipc, posn.rhdr.hdr.cmd, &posn,
diff --git a/src/lib/dma-trace.c b/src/lib/dma-trace.c
index 0dccf7e..ea63ab4 100644
--- a/src/lib/dma-trace.c
+++ b/src/lib/dma-trace.c
@@ -60,8 +60,12 @@ static uint64_t trace_work(void *data, uint64_t delay)
 	d->copy_in_progress = 1;
 
 	/* make sure we dont write more than buffer */
-	if (avail > DMA_TRACE_LOCAL_SIZE)
+	if (avail > DMA_TRACE_LOCAL_SIZE) {
+		d->overflow = avail - DMA_TRACE_LOCAL_SIZE;
 		avail = DMA_TRACE_LOCAL_SIZE;
+	} else {
+		d->overflow = 0;
+	}
 
 	/* copy to host in sections if we wrap */
 	lsize = hsize = avail;
@@ -134,6 +138,8 @@ int dma_trace_init_early(struct dma_trace_data *d)
 	buffer->end_addr = buffer->addr + buffer->size;
 	buffer->avail = 0;
 	d->host_offset = 0;
+	d->overflow = 0;
+	d->messages = 0;
 	d->enabled = 0;
 	d->copy_in_progress = 0;
 
@@ -217,6 +223,7 @@ static void dtrace_add_event(const char *e, uint32_t length)
 	}
 
 	buffer->avail += length;
+	trace_data->messages++;
 }
 
 void dtrace_event(const char *e, uint32_t length)
-- 
2.14.1