ASoC: SOF: trace: move to opt-in with Kconfig and module parameter

In a number of debug cases, the DMA-based trace can add problems
(e.g. with HDaudio channel allocation). It also generates additional
traffic on the bus and if the DMA handling is unreliable will prevent
audio use-cases from working normally. Using the trace also requires
tools to be installed on the target.

The trace can be instead handled as dynamic debug. We can use a
Kconfig to force the trace to be enabled in all cases, or use a module
parameter to enable it on a need-basis, e.g. by setting "options
snd_sof sof_debug=0x1" in a /etc/modprobe.d file.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190927200538.660-4-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 16 insertions, 1 deletions

diff --git a/sound/soc/sof/trace.c b/sound/soc/sof/trace.c
index 4c3cff031fd6..b0e4556c8536 100644
--- a/sound/soc/sof/trace.c
+++ b/sound/soc/sof/trace.c
@@ -162,6 +162,9 @@ int snd_sof_init_trace_ipc(struct snd_sof_dev *sdev)
 	struct sof_ipc_reply ipc_reply;
 	int ret;
 
+	if (!sdev->dtrace_is_supported)
+		return 0;
+
 	if (sdev->dtrace_is_enabled || !sdev->dma_trace_pages)
 		return -EINVAL;
 
@@ -222,6 +225,9 @@ int snd_sof_init_trace(struct snd_sof_dev *sdev)
 {
 	int ret;
 
+	if (!sdev->dtrace_is_supported)
+		return 0;
+
 	/* set false before start initialization */
 	sdev->dtrace_is_enabled = false;
 
@@ -277,6 +283,9 @@ EXPORT_SYMBOL(snd_sof_init_trace);
 int snd_sof_trace_update_pos(struct snd_sof_dev *sdev,
 			     struct sof_ipc_dma_trace_posn *posn)
 {
+	if (!sdev->dtrace_is_supported)
+		return 0;
+
 	if (sdev->dtrace_is_enabled && sdev->host_offset != posn->host_offset) {
 		sdev->host_offset = posn->host_offset;
 		wake_up(&sdev->trace_sleep);
@@ -293,6 +302,9 @@ int snd_sof_trace_update_pos(struct snd_sof_dev *sdev,
 /* an error has occurred within the DSP that prevents further trace */
 void snd_sof_trace_notify_for_error(struct snd_sof_dev *sdev)
 {
+	if (!sdev->dtrace_is_supported)
+		return;
+
 	if (sdev->dtrace_is_enabled) {
 		dev_err(sdev->dev, "error: waking up any trace sleepers\n");
 		sdev->dtrace_error = true;
@@ -305,7 +317,7 @@ void snd_sof_release_trace(struct snd_sof_dev *sdev)
 {
 	int ret;
 
-	if (!sdev->dtrace_is_enabled)
+	if (!sdev->dtrace_is_supported || !sdev->dtrace_is_enabled)
 		return;
 
 	ret = snd_sof_dma_trace_trigger(sdev, SNDRV_PCM_TRIGGER_STOP);
@@ -326,6 +338,9 @@ EXPORT_SYMBOL(snd_sof_release_trace);
 
 void snd_sof_free_trace(struct snd_sof_dev *sdev)
 {
+	if (!sdev->dtrace_is_supported)
+		return;
+
 	snd_sof_release_trace(sdev);
 
 	snd_dma_free_pages(&sdev->dmatb);