ASoC/soundwire: log actual PING status on resume issues

Merge series from Bard Liao <yung-chuan.liao@linux.intel.com>:

we've been stuck with problems in the dual-amplifier configurations where
one of the two devices seems to become UNATTACHED and never regains sync,
see https://github.com/thesofproject/linux/issues/3638.

This is a rather infrequent issue that may happen once or twice per month,
but still it remains a concern.

One possibility is that the device does lose sync but somehow our hardware
detection fails to see it resync.

This series just adds a basic read directly from the PING frames to help
confirm if yes/no the device regain sync.

drivers/soundwire/bus.c

@@ -297,6 +297,38 @@ int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 	return ret;
 }
 
+/**
+ * sdw_show_ping_status() - Direct report of PING status, to be used by Peripheral drivers
+ * @bus: SDW bus
+ * @sync_delay: Delay before reading status
+ */
+void sdw_show_ping_status(struct sdw_bus *bus, bool sync_delay)
+{
+	u32 status;
+
+	if (!bus->ops->read_ping_status)
+		return;
+
+	/*
+	 * wait for peripheral to sync if desired. 10-15ms should be more than
+	 * enough in most cases.
+	 */
+	if (sync_delay)
+		usleep_range(10000, 15000);
+
+	mutex_lock(&bus->msg_lock);
+
+	status = bus->ops->read_ping_status(bus);
+
+	mutex_unlock(&bus->msg_lock);
+
+	if (!status)
+		dev_warn(bus->dev, "%s: no peripherals attached\n", __func__);
+	else
+		dev_dbg(bus->dev, "PING status: %#x\n", status);
+}
+EXPORT_SYMBOL(sdw_show_ping_status);
+
 /**
  * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
  * @bus: SDW bus

drivers/soundwire/cadence_master.c

@@ -756,6 +756,14 @@ cdns_reset_page_addr(struct sdw_bus *bus, unsigned int dev_num)
 }
 EXPORT_SYMBOL(cdns_reset_page_addr);
 
+u32 cdns_read_ping_status(struct sdw_bus *bus)
+{
+	struct sdw_cdns *cdns = bus_to_cdns(bus);
+
+	return cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);
+}
+EXPORT_SYMBOL(cdns_read_ping_status);
+
 /*
  * IRQ handling
  */

drivers/soundwire/cadence_master.h

@@ -177,6 +177,8 @@ enum sdw_command_response
 cdns_xfer_msg_defer(struct sdw_bus *bus,
 		    struct sdw_msg *msg, struct sdw_defer *defer);
 
+u32 cdns_read_ping_status(struct sdw_bus *bus);
+
 int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params);
 
 int cdns_set_sdw_stream(struct snd_soc_dai *dai,

drivers/soundwire/intel.c

@@ -1262,6 +1262,7 @@ static struct sdw_master_ops sdw_intel_ops = {
 	.set_bus_conf = cdns_bus_conf,
 	.pre_bank_switch = intel_pre_bank_switch,
 	.post_bank_switch = intel_post_bank_switch,
+	.read_ping_status = cdns_read_ping_status,
 };
 
 static int intel_init(struct sdw_intel *sdw)

include/linux/soundwire/sdw.h

@@ -839,6 +839,8 @@ struct sdw_defer {
  * @set_bus_conf: Set the bus configuration
  * @pre_bank_switch: Callback for pre bank switch
  * @post_bank_switch: Callback for post bank switch
+ * @read_ping_status: Read status from PING frames, reported with two bits per Device.
+ * Bits 31:24 are reserved.
  */
 struct sdw_master_ops {
 	int (*read_prop)(struct sdw_bus *bus);
@@ -855,6 +857,7 @@ struct sdw_master_ops {
 			struct sdw_bus_params *params);
 	int (*pre_bank_switch)(struct sdw_bus *bus);
 	int (*post_bank_switch)(struct sdw_bus *bus);
+	u32 (*read_ping_status)(struct sdw_bus *bus);
 
 };
 
@@ -919,6 +922,8 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
 		       struct fwnode_handle *fwnode);
 void sdw_bus_master_delete(struct sdw_bus *bus);
 
+void sdw_show_ping_status(struct sdw_bus *bus, bool sync_delay);
+
 /**
  * sdw_port_config: Master or Slave Port configuration
  *

sound/soc/codecs/max98373-sdw.c

@@ -281,6 +281,8 @@ static __maybe_unused int max98373_resume(struct device *dev)
 					   msecs_to_jiffies(MAX98373_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt1308-sdw.c

@@ -749,6 +749,8 @@ static int __maybe_unused rt1308_dev_resume(struct device *dev)
 				msecs_to_jiffies(RT1308_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt1316-sdw.c

@@ -734,6 +734,8 @@ static int __maybe_unused rt1316_dev_resume(struct device *dev)
 				msecs_to_jiffies(RT1316_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt5682-sdw.c

@@ -793,6 +793,8 @@ static int __maybe_unused rt5682_dev_resume(struct device *dev)
 				msecs_to_jiffies(RT5682_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt700-sdw.c

@@ -542,6 +542,8 @@ static int __maybe_unused rt700_dev_resume(struct device *dev)
 				msecs_to_jiffies(RT700_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt711-sdca-sdw.c

@@ -449,6 +449,8 @@ static int __maybe_unused rt711_sdca_dev_resume(struct device *dev)
 				msecs_to_jiffies(RT711_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt715-sdca-sdw.c

@@ -244,6 +244,8 @@ static int __maybe_unused rt715_dev_resume(struct device *dev)
 					   msecs_to_jiffies(RT715_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Enumeration not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}
 

sound/soc/codecs/rt715-sdw.c

@@ -562,6 +562,8 @@ static int __maybe_unused rt715_dev_resume(struct device *dev)
 					   msecs_to_jiffies(RT715_PROBE_TIMEOUT));
 	if (!time) {
 		dev_err(&slave->dev, "Initialization not complete, timed out\n");
+		sdw_show_ping_status(slave->bus, true);
+
 		return -ETIMEDOUT;
 	}