From aa79293517b395c6094a382779c911689e8c9a8b Mon Sep 17 00:00:00 2001
From: Rander Wang <rander.wang@intel.com>
Date: Tue, 14 Jan 2020 18:08:42 -0600
Subject: [PATCH] soundwire: bus: fix io error when processing alert event
Git-commit: aa79293517b395c6094a382779c911689e8c9a8b
Patch-mainline: v5.7-rc1
References: jsc#SLE-16518

There are two types of io errors when processing alert event.

a) the Master detects an ALERT status for e.g. a jack event and
invokes the implementation-defined function in the Slave driver to
check the jack status. At this time the codec is just suspended, so io
registers can't be accessed.

b) when waking up from clock stop mode1 state, where the bus needs a
complete re-enumeration, Slave registers can't be accessed until the
enumeration is complete.

This patch resumes the Slave device and waits for initialization
complete when processing slave alert event, so that registers on the
Slave can be accessed without timeouts or io errors.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-9-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 | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 33bb273454cf..23bc24c8e9d1 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -890,12 +890,19 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 
 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
 
+	ret = pm_runtime_get_sync(&slave->dev);
+	if (ret < 0 && ret != -EACCES) {
+		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
+		pm_runtime_put_noidle(slave->bus->dev);
+		return ret;
+	}
+
 	/* Read Instat 1, Instat 2 and Instat 3 registers */
 	ret = sdw_read(slave, SDW_SCP_INT1);
 	if (ret < 0) {
 		dev_err(slave->bus->dev,
 			"SDW_SCP_INT1 read failed:%d\n", ret);
-		return ret;
+		goto io_err;
 	}
 	buf = ret;
 
@@ -903,7 +910,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 	if (ret < 0) {
 		dev_err(slave->bus->dev,
 			"SDW_SCP_INT2/3 read failed:%d\n", ret);
-		return ret;
+		goto io_err;
 	}
 
 	do {
@@ -983,7 +990,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 				"SDW_SCP_INT1 write failed:%d\n", ret);
-			return ret;
+			goto io_err;
 		}
 
 		/*
@@ -994,7 +1001,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 				"SDW_SCP_INT1 read failed:%d\n", ret);
-			return ret;
+			goto io_err;
 		}
 		_buf = ret;
 
@@ -1002,7 +1009,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 				"SDW_SCP_INT2/3 read failed:%d\n", ret);
-			return ret;
+			goto io_err;
 		}
 
 		/* Make sure no interrupts are pending */
@@ -1023,6 +1030,10 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 	if (count == SDW_READ_INTR_CLEAR_RETRY)
 		dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n");
 
+io_err:
+	pm_runtime_mark_last_busy(&slave->dev);
+	pm_runtime_put_autosuspend(&slave->dev);
+
 	return ret;
 }
 
-- 
2.16.4