From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

In rare cases, some devices seem to lose sync and never re-attach on the bus. This seems to happen only when there are more than one device per link, which suggests either an electrical issue, a race condition or a state machine issue.

Add two dev_warn() messages to identify the sequence by which the devices become UNATTACHED.

BugLink: https://github.com/thesofproject/linux/issues/3063 BugLink: https://github.com/thesofproject/linux/issues/3325 Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/bus.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 67369e941d0d..354d3f89366f 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1749,8 +1749,11 @@ int sdw_handle_slave_status(struct sdw_bus *bus, continue;

if (status[i] == SDW_SLAVE_UNATTACHED && - slave->status != SDW_SLAVE_UNATTACHED) + slave->status != SDW_SLAVE_UNATTACHED) { + dev_warn(&slave->dev, "Slave %d state check1: UNATTACHED, status was %d\n", + i, slave->status); sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); + } }

if (status[0] == SDW_SLAVE_ATTACHED) { @@ -1785,6 +1788,9 @@ int sdw_handle_slave_status(struct sdw_bus *bus, if (slave->status == SDW_SLAVE_UNATTACHED) break;

+ dev_warn(&slave->dev, "Slave %d state check2: UNATTACHED, status was %d\n", + i, slave->status); + sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); break;