1 files changed, 79 insertions, 22 deletions

diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index 48a63ca130d2..19919975bb6d 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -29,10 +29,17 @@ static int sdw_slave_add(struct sdw_bus *bus,
 	slave->dev.parent = bus->dev;
 	slave->dev.fwnode = fwnode;
 
-	/* name shall be sdw:link:mfg:part:class:unique */
-	dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
-		     bus->link_id, id->mfg_id, id->part_id,
-		     id->class_id, id->unique_id);
+	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
+		/* name shall be sdw:link:mfg:part:class */
+		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
+			     bus->link_id, id->mfg_id, id->part_id,
+			     id->class_id);
+	} else {
+		/* name shall be sdw:link:mfg:part:class:unique */
+		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
+			     bus->link_id, id->mfg_id, id->part_id,
+			     id->class_id, id->unique_id);
+	}
 
 	slave->dev.release = sdw_slave_release;
 	slave->dev.bus = &sdw_bus_type;
@@ -64,6 +71,36 @@ static int sdw_slave_add(struct sdw_bus *bus,
 }
 
 #if IS_ENABLED(CONFIG_ACPI)
+
+static bool find_slave(struct sdw_bus *bus,
+		       struct acpi_device *adev,
+		       struct sdw_slave_id *id)
+{
+	unsigned long long addr;
+	unsigned int link_id;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(adev->handle,
+				       METHOD_NAME__ADR, NULL, &addr);
+
+	if (ACPI_FAILURE(status)) {
+		dev_err(bus->dev, "_ADR resolution failed: %x\n",
+			status);
+		return false;
+	}
+
+	/* Extract link id from ADR, Bit 51 to 48 (included) */
+	link_id = (addr >> 48) & GENMASK(3, 0);
+
+	/* Check for link_id match */
+	if (link_id != bus->link_id)
+		return false;
+
+	sdw_extract_slave_id(bus, addr, id);
+
+	return true;
+}
+
 /*
  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
  * @bus: SDW bus instance
@@ -73,6 +110,7 @@ static int sdw_slave_add(struct sdw_bus *bus,
 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 {
 	struct acpi_device *adev, *parent;
+	struct acpi_device *adev2, *parent2;
 
 	parent = ACPI_COMPANION(bus->dev);
 	if (!parent) {
@@ -81,28 +119,46 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus)
 	}
 
 	list_for_each_entry(adev, &parent->children, node) {
-		unsigned long long addr;
 		struct sdw_slave_id id;
-		unsigned int link_id;
-		acpi_status status;
+		struct sdw_slave_id id2;
+		bool ignore_unique_id = true;
 
-		status = acpi_evaluate_integer(adev->handle,
-					       METHOD_NAME__ADR, NULL, &addr);
+		if (!find_slave(bus, adev, &id))
+			continue;
 
-		if (ACPI_FAILURE(status)) {
-			dev_err(bus->dev, "_ADR resolution failed: %x\n",
-				status);
-			return status;
+		/* brute-force O(N^2) search for duplicates */
+		parent2 = parent;
+		list_for_each_entry(adev2, &parent2->children, node) {
+
+			if (adev == adev2)
+				continue;
+
+			if (!find_slave(bus, adev2, &id2))
+				continue;
+
+			if (id.sdw_version != id2.sdw_version ||
+			    id.mfg_id != id2.mfg_id ||
+			    id.part_id != id2.part_id ||
+			    id.class_id != id2.class_id)
+				continue;
+
+			if (id.unique_id != id2.unique_id) {
+				dev_dbg(bus->dev,
+					"Valid unique IDs %x %x for Slave mfg %x part %d\n",
+					id.unique_id, id2.unique_id,
+					id.mfg_id, id.part_id);
+				ignore_unique_id = false;
+			} else {
+				dev_err(bus->dev,
+					"Invalid unique IDs %x %x for Slave mfg %x part %d\n",
+					id.unique_id, id2.unique_id,
+					id.mfg_id, id.part_id);
+				return -ENODEV;
+			}
 		}
 
-		/* Extract link id from ADR, Bit 51 to 48 (included) */
-		link_id = (addr >> 48) & GENMASK(3, 0);
-
-		/* Check for link_id match */
-		if (link_id != bus->link_id)
-			continue;
-
-		sdw_extract_slave_id(bus, addr, &id);
+		if (ignore_unique_id)
+			id.unique_id = SDW_IGNORED_UNIQUE_ID;
 
 		/*
 		 * don't error check for sdw_slave_add as we want to continue
@@ -128,7 +184,8 @@ int sdw_of_find_slaves(struct sdw_bus *bus)
 	struct device_node *node;
 
 	for_each_child_of_node(bus->dev->of_node, node) {
-		int link_id, sdw_version, ret, len;
+		int link_id, ret, len;
+		unsigned int sdw_version;
 		const char *compat = NULL;
 		struct sdw_slave_id id;
 		const __be32 *addr;