[PATCH 08/11] soundwire: stream: enable hw_sync as needed by hardware

From: Bard Liao
Date: Tue Aug 18 2020 - 10:35:51 EST


From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

Use platform-specific information to decide when to use hw_sync, not
only a number of links > 1.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
drivers/soundwire/stream.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 37290a799023..e4cf484f5905 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -689,9 +689,9 @@ static int sdw_bank_switch(struct sdw_bus *bus, int m_rt_count)

/*
* Set the multi_link flag only when both the hardware supports
- * and there is a stream handled by multiple masters
+ * and hardware-based sync is required
*/
- multi_link = bus->multi_link && (m_rt_count > 1);
+ multi_link = bus->multi_link && (m_rt_count >= bus->hw_sync_min_links);

if (multi_link)
ret = sdw_transfer_defer(bus, wr_msg, &bus->defer_msg);
@@ -760,13 +760,16 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
const struct sdw_master_ops *ops;
struct sdw_bus *bus;
bool multi_link = false;
+ int m_rt_count;
int ret = 0;

+ m_rt_count = stream->m_rt_count;
+
list_for_each_entry(m_rt, &stream->master_list, stream_node) {
bus = m_rt->bus;
ops = bus->ops;

- if (bus->multi_link) {
+ if (bus->multi_link && m_rt_count >= bus->hw_sync_min_links) {
multi_link = true;
mutex_lock(&bus->msg_lock);
}
@@ -787,7 +790,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
* synchronized across all Masters and happens later as a
* part of post_bank_switch ops.
*/
- ret = sdw_bank_switch(bus, stream->m_rt_count);
+ ret = sdw_bank_switch(bus, m_rt_count);
if (ret < 0) {
dev_err(bus->dev, "Bank switch failed: %d\n", ret);
goto error;
@@ -813,7 +816,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
ret);
goto error;
}
- } else if (bus->multi_link && stream->m_rt_count > 1) {
+ } else if (multi_link) {
dev_err(bus->dev,
"Post bank switch ops not implemented\n");
goto error;
@@ -831,7 +834,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
goto error;
}

- if (bus->multi_link)
+ if (multi_link)
mutex_unlock(&bus->msg_lock);
}

--
2.17.1