7 files changed, 109 insertions, 25 deletions

diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
index d928258c6761..77dc094075e1 100644
--- a/drivers/soundwire/bus_type.c
+++ b/drivers/soundwire/bus_type.c
@@ -83,7 +83,6 @@ static int sdw_drv_probe(struct device *dev)
 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 	struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 	const struct sdw_device_id *id;
-	const char *name;
 	int ret;
 
 	/*
@@ -108,11 +107,6 @@ static int sdw_drv_probe(struct device *dev)
 
 	ret = drv->probe(slave, id);
 	if (ret) {
-		name = drv->name;
-		if (!name)
-			name = drv->driver.name;
-
-		dev_err(dev, "Probe of %s failed: %d\n", name, ret);
 		dev_pm_domain_detach(dev, false);
 		return ret;
 	}
@@ -129,7 +123,7 @@ static int sdw_drv_probe(struct device *dev)
 	/* init the dynamic sysfs attributes we need */
 	ret = sdw_slave_sysfs_dpn_init(slave);
 	if (ret < 0)
-		dev_warn(dev, "Slave sysfs init failed:%d\n", ret);
+		dev_warn(dev, "failed to initialise sysfs: %d\n", ret);
 
 	/*
 	 * Check for valid clk_stop_timeout, use DisCo worst case value of
@@ -153,7 +147,7 @@ static int sdw_drv_probe(struct device *dev)
 	if (drv->ops && drv->ops->update_status) {
 		ret = drv->ops->update_status(slave, slave->status);
 		if (ret < 0)
-			dev_warn(dev, "%s: update_status failed with status %d\n", __func__, ret);
+			dev_warn(dev, "failed to update status at probe: %d\n", ret);
 	}
 
 	mutex_unlock(&slave->sdw_dev_lock);
@@ -204,16 +198,11 @@ static void sdw_drv_shutdown(struct device *dev)
  */
 int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
 {
-	const char *name;
-
 	drv->driver.bus = &sdw_bus_type;
 
 	if (!drv->probe) {
-		name = drv->name;
-		if (!name)
-			name = drv->driver.name;
-
-		pr_err("driver %s didn't provide SDW probe routine\n", name);
+		pr_err("driver %s didn't provide SDW probe routine\n",
+				drv->driver.name);
 		return -EINVAL;
 	}
 
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index e0683a5975d1..05652e983539 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -890,8 +890,14 @@ static int cdns_update_slave_status(struct sdw_cdns *cdns,
 		}
 	}
 
-	if (is_slave)
-		return sdw_handle_slave_status(&cdns->bus, status);
+	if (is_slave) {
+		int ret;
+
+		mutex_lock(&cdns->status_update_lock);
+		ret = sdw_handle_slave_status(&cdns->bus, status);
+		mutex_unlock(&cdns->status_update_lock);
+		return ret;
+	}
 
 	return 0;
 }
@@ -988,6 +994,31 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id)
 }
 EXPORT_SYMBOL(sdw_cdns_irq);
 
+static void cdns_check_attached_status_dwork(struct work_struct *work)
+{
+	struct sdw_cdns *cdns =
+		container_of(work, struct sdw_cdns, attach_dwork.work);
+	enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
+	u32 val;
+	int ret;
+	int i;
+
+	val = cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);
+
+	for (i = 0; i <= SDW_MAX_DEVICES; i++) {
+		status[i] = val & 0x3;
+		if (status[i])
+			dev_dbg(cdns->dev, "Peripheral %d status: %d\n", i, status[i]);
+		val >>= 2;
+	}
+
+	mutex_lock(&cdns->status_update_lock);
+	ret = sdw_handle_slave_status(&cdns->bus, status);
+	mutex_unlock(&cdns->status_update_lock);
+	if (ret < 0)
+		dev_err(cdns->dev, "%s: sdw_handle_slave_status failed: %d\n", __func__, ret);
+}
+
 /**
  * cdns_update_slave_status_work - update slave status in a work since we will need to handle
  * other interrupts eg. CDNS_MCP_INT_RX_WL during the update slave
@@ -1740,7 +1771,11 @@ int sdw_cdns_probe(struct sdw_cdns *cdns)
 	init_completion(&cdns->tx_complete);
 	cdns->bus.port_ops = &cdns_port_ops;
 
+	mutex_init(&cdns->status_update_lock);
+
 	INIT_WORK(&cdns->work, cdns_update_slave_status_work);
+	INIT_DELAYED_WORK(&cdns->attach_dwork, cdns_check_attached_status_dwork);
+
 	return 0;
 }
 EXPORT_SYMBOL(sdw_cdns_probe);
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index bc84435e420f..e1d7969ba48a 100644
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -117,6 +117,8 @@ struct sdw_cdns_dai_runtime {
  * @link_up: Link status
  * @msg_count: Messages sent on bus
  * @dai_runtime_array: runtime context for each allocated DAI.
+ * @status_update_lock: protect concurrency between interrupt-based and delayed work
+ * status update
  */
 struct sdw_cdns {
 	struct device *dev;
@@ -148,10 +150,13 @@ struct sdw_cdns {
 	bool interrupt_enabled;
 
 	struct work_struct work;
+	struct delayed_work attach_dwork;
 
 	struct list_head list;
 
 	struct sdw_cdns_dai_runtime **dai_runtime_array;
+
+	struct mutex status_update_lock; /* add mutual exclusion to sdw_handle_slave_status() */
 };
 
 #define bus_to_cdns(_bus) container_of(_bus, struct sdw_cdns, bus)
diff --git a/drivers/soundwire/intel.h b/drivers/soundwire/intel.h
index 68838e843b54..dddd29381441 100644
--- a/drivers/soundwire/intel.h
+++ b/drivers/soundwire/intel.h
@@ -103,6 +103,8 @@ static inline void intel_writew(void __iomem *base, int offset, u16 value)
 
 #define INTEL_MASTER_RESET_ITERATIONS	10
 
+#define SDW_INTEL_DELAYED_ENUMERATION_MS	100
+
 #define SDW_INTEL_CHECK_OPS(sdw, cb)	((sdw) && (sdw)->link_res && (sdw)->link_res->hw_ops && \
 					 (sdw)->link_res->hw_ops->cb)
 #define SDW_INTEL_OPS(sdw, cb)		((sdw)->link_res->hw_ops->cb)
@@ -222,6 +224,13 @@ static inline bool sdw_intel_sync_check_cmdsync_unlocked(struct sdw_intel *sdw)
 	return false;
 }
 
+static inline int sdw_intel_get_link_count(struct sdw_intel *sdw)
+{
+	if (SDW_INTEL_CHECK_OPS(sdw, get_link_count))
+		return SDW_INTEL_OPS(sdw, get_link_count)(sdw);
+	return 4; /* default on older generations */
+}
+
 /* common bus management */
 int intel_start_bus(struct sdw_intel *sdw);
 int intel_start_bus_after_reset(struct sdw_intel *sdw);
diff --git a/drivers/soundwire/intel_ace2x.c b/drivers/soundwire/intel_ace2x.c
index 781fe0aefa68..fff312c6968d 100644
--- a/drivers/soundwire/intel_ace2x.c
+++ b/drivers/soundwire/intel_ace2x.c
@@ -706,10 +706,30 @@ static void intel_program_sdi(struct sdw_intel *sdw, int dev_num)
 			__func__, sdw->instance, dev_num);
 }
 
+static int intel_get_link_count(struct sdw_intel *sdw)
+{
+	int ret;
+
+	ret = hdac_bus_eml_get_count(sdw->link_res->hbus, true, AZX_REG_ML_LEPTR_ID_SDW);
+	if (!ret) {
+		dev_err(sdw->cdns.dev, "%s: could not retrieve link count\n", __func__);
+		return -ENODEV;
+	}
+
+	if (ret > SDW_INTEL_MAX_LINKS) {
+		dev_err(sdw->cdns.dev, "%s: link count %d exceed max %d\n", __func__, ret, SDW_INTEL_MAX_LINKS);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
 const struct sdw_intel_hw_ops sdw_intel_lnl_hw_ops = {
 	.debugfs_init = intel_ace2x_debugfs_init,
 	.debugfs_exit = intel_ace2x_debugfs_exit,
 
+	.get_link_count = intel_get_link_count,
+
 	.register_dai = intel_register_dai,
 
 	.check_clock_stop = intel_check_clock_stop,
diff --git a/drivers/soundwire/intel_auxdevice.c b/drivers/soundwire/intel_auxdevice.c
index 8807e01cbf7c..ae689d5d1ab9 100644
--- a/drivers/soundwire/intel_auxdevice.c
+++ b/drivers/soundwire/intel_auxdevice.c
@@ -317,6 +317,20 @@ static int intel_link_probe(struct auxiliary_device *auxdev,
 	bus->link_id = auxdev->id;
 	bus->clk_stop_timeout = 1;
 
+	/*
+	 * paranoia check: make sure ACPI-reported number of links is aligned with
+	 * hardware capabilities.
+	 */
+	ret = sdw_intel_get_link_count(sdw);
+	if (ret < 0) {
+		dev_err(dev, "%s: sdw_intel_get_link_count failed: %d\n", __func__, ret);
+		return ret;
+	}
+	if (ret <= sdw->instance) {
+		dev_err(dev, "%s: invalid link id %d, link count %d\n", __func__, auxdev->id, ret);
+		return -EINVAL;
+	}
+
 	sdw_cdns_probe(cdns);
 
 	/* Set ops */
@@ -475,6 +489,7 @@ static void intel_link_remove(struct auxiliary_device *auxdev)
 	 */
 	if (!bus->prop.hw_disabled) {
 		sdw_intel_debugfs_exit(sdw);
+		cancel_delayed_work_sync(&cdns->attach_dwork);
 		sdw_cdns_enable_interrupt(cdns, false);
 	}
 	sdw_bus_master_delete(bus);
diff --git a/drivers/soundwire/intel_bus_common.c b/drivers/soundwire/intel_bus_common.c
index df944e11b9ca..d3ff6c65b64c 100644
--- a/drivers/soundwire/intel_bus_common.c
+++ b/drivers/soundwire/intel_bus_common.c
@@ -45,21 +45,24 @@ int intel_start_bus(struct sdw_intel *sdw)
 		return ret;
 	}
 
-	ret = sdw_cdns_exit_reset(cdns);
+	ret = sdw_cdns_enable_interrupt(cdns, true);
 	if (ret < 0) {
-		dev_err(dev, "%s: unable to exit bus reset sequence: %d\n", __func__, ret);
+		dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret);
 		return ret;
 	}
 
-	ret = sdw_cdns_enable_interrupt(cdns, true);
+	ret = sdw_cdns_exit_reset(cdns);
 	if (ret < 0) {
-		dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret);
+		dev_err(dev, "%s: unable to exit bus reset sequence: %d\n", __func__, ret);
 		return ret;
 	}
 
 	sdw_cdns_check_self_clearing_bits(cdns, __func__,
 					  true, INTEL_MASTER_RESET_ITERATIONS);
 
+	schedule_delayed_work(&cdns->attach_dwork,
+			      msecs_to_jiffies(SDW_INTEL_DELAYED_ENUMERATION_MS));
+
 	return 0;
 }
 
@@ -136,21 +139,24 @@ int intel_start_bus_after_reset(struct sdw_intel *sdw)
 			return ret;
 		}
 
-		ret = sdw_cdns_exit_reset(cdns);
+		ret = sdw_cdns_enable_interrupt(cdns, true);
 		if (ret < 0) {
-			dev_err(dev, "unable to exit bus reset sequence during resume\n");
+			dev_err(dev, "cannot enable interrupts during resume\n");
 			return ret;
 		}
 
-		ret = sdw_cdns_enable_interrupt(cdns, true);
+		ret = sdw_cdns_exit_reset(cdns);
 		if (ret < 0) {
-			dev_err(dev, "cannot enable interrupts during resume\n");
+			dev_err(dev, "unable to exit bus reset sequence during resume\n");
 			return ret;
 		}
 
 	}
 	sdw_cdns_check_self_clearing_bits(cdns, __func__, true, INTEL_MASTER_RESET_ITERATIONS);
 
+	schedule_delayed_work(&cdns->attach_dwork,
+			      msecs_to_jiffies(SDW_INTEL_DELAYED_ENUMERATION_MS));
+
 	return 0;
 }
 
@@ -184,6 +190,9 @@ int intel_start_bus_after_clock_stop(struct sdw_intel *sdw)
 
 	sdw_cdns_check_self_clearing_bits(cdns, __func__, true, INTEL_MASTER_RESET_ITERATIONS);
 
+	schedule_delayed_work(&cdns->attach_dwork,
+			      msecs_to_jiffies(SDW_INTEL_DELAYED_ENUMERATION_MS));
+
 	return 0;
 }
 
@@ -194,6 +203,8 @@ int intel_stop_bus(struct sdw_intel *sdw, bool clock_stop)
 	bool wake_enable = false;
 	int ret;
 
+	cancel_delayed_work_sync(&cdns->attach_dwork);
+
 	if (clock_stop) {
 		ret = sdw_cdns_clock_stop(cdns, true);
 		if (ret < 0)