[alsa-devel] [PATCH 6/6] soundwire: stream: don't program ports for a stream that has not been prepared

[Pierre-Louis Bossart]

From: Rander Wang <rander.wang at intel.com>

In the Intel QA multi-pipelines test case, there are two pipelines for
playback and capture on the same bus. The test fails with an error
when setting port params:

[  599.224812] rt711 sdw:0:25d:711:0: invalid dpn_prop direction 1 port_num 0
[  599.224815] sdw_program_slave_port_params failed -22
[  599.224819] intel-sdw sdw-master-0: Program transport params failed: -22
[  599.224822] intel-sdw sdw-master-0: Program params failed: -22
[  599.224828] sdw_enable_stream: SDW0 Pin2-Playback: done

This problem is root-caused to the programming of the capture stream
ports while it is not yet prepared, the calling sequence is:

(1) hw_params for playback. The playback stream provide the port
    information to Bus.
(2) stream_prepare for playback, Transport and port parameters
    are computed for playback.
(3) hw_params for capture. The capture stream provide the port
    information to Bus, but it has not been prepared so is not
    accounted for in the bandwidth allocation.
(4) stream_enable for playback. Program transport and port parameters
    for all masters and slaves. Since the transport and port parameters
    are not computed for capture stream, sdw_program_slave_port_params
    will generate a error when setting port params for capture.

in step (4), we should only program the ports for the stream that have
been prepared. A stream that is only in CONFIGURED state should be
ignored, its ports will be programmed when it becomes PREPARED.

Tested on Comet Lake.

GitHub issue: https://github.com/thesofproject/linux/issues/1637
Signed-off-by: Rander Wang <rander.wang at intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 drivers/soundwire/stream.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index da10f38298c0..198372977187 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -604,12 +604,23 @@ static int sdw_notify_config(struct sdw_master_runtime *m_rt)
  *
  * @bus: SDW bus instance
  */
-static int sdw_program_params(struct sdw_bus *bus)
+static int sdw_program_params(struct sdw_bus *bus, bool prepare)
 {
 	struct sdw_master_runtime *m_rt;
 	int ret = 0;
 
 	list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
+
+		/*
+		 * this loop walks through all master runtimes for a
+		 * bus, but the ports can only be configured while
+		 * explicitly preparing a stream or handling an
+		 * already-prepared stream otherwise.
+		 */
+		if (!prepare &&
+		    m_rt->stream->state == SDW_STREAM_CONFIGURED)
+			continue;
+
 		ret = sdw_program_port_params(m_rt);
 		if (ret < 0) {
 			dev_err(bus->dev,
@@ -1502,7 +1513,7 @@ static int _sdw_prepare_stream(struct sdw_stream_runtime *stream,
 
 program_params:
 		/* Program params */
-		ret = sdw_program_params(bus);
+		ret = sdw_program_params(bus, true);
 		if (ret < 0) {
 			dev_err(bus->dev, "Program params failed: %d\n", ret);
 			goto restore_params;
@@ -1602,7 +1613,7 @@ static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
 		bus = m_rt->bus;
 
 		/* Program params */
-		ret = sdw_program_params(bus);
+		ret = sdw_program_params(bus, false);
 		if (ret < 0) {
 			dev_err(bus->dev, "Program params failed: %d\n", ret);
 			return ret;
@@ -1687,7 +1698,7 @@ static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
 		struct sdw_bus *bus = m_rt->bus;
 
 		/* Program params */
-		ret = sdw_program_params(bus);
+		ret = sdw_program_params(bus, false);
 		if (ret < 0) {
 			dev_err(bus->dev, "Program params failed: %d\n", ret);
 			return ret;
@@ -1769,7 +1780,7 @@ static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream)
 			m_rt->ch_count * m_rt->stream->params.bps;
 
 		/* Program params */
-		ret = sdw_program_params(bus);
+		ret = sdw_program_params(bus, false);
 		if (ret < 0) {
 			dev_err(bus->dev, "Program params failed: %d\n", ret);
 			return ret;
-- 
2.20.1