From 6106190158d6b6a064c907a2ba3e063d06f89eaa Mon Sep 17 00:00:00 2001
From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Date: Fri, 10 Jan 2020 15:57:31 -0600
Subject: [PATCH] soundwire: bus: check first if Slaves become UNATTACHED
Git-commit: 6106190158d6b6a064c907a2ba3e063d06f89eaa
Patch-mainline: v5.6-rc1
References: jsc#SLE-16518

Before checking for the presence of Device0, we first need to clean-up
the internal state of Slaves that are no longer attached.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200110215731.30747-7-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/soundwire/bus.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index be5d437058ed..66fd09e36b73 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -979,6 +979,24 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 	struct sdw_slave *slave;
 	int i, ret = 0;
 
+	/* first check if any Slaves fell off the bus */
+	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+		mutex_lock(&bus->bus_lock);
+		if (test_bit(i, bus->assigned) == false) {
+			mutex_unlock(&bus->bus_lock);
+			continue;
+		}
+		mutex_unlock(&bus->bus_lock);
+
+		slave = sdw_get_slave(bus, i);
+		if (!slave)
+			continue;
+
+		if (status[i] == SDW_SLAVE_UNATTACHED &&
+		    slave->status != SDW_SLAVE_UNATTACHED)
+			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
+	}
+
 	if (status[0] == SDW_SLAVE_ATTACHED) {
 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
 		ret = sdw_program_device_num(bus);
-- 
2.16.4