Blob Blame History Raw
From 973794e85610d9a716a897baa9007ff56e192826 Mon Sep 17 00:00:00 2001
From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Date: Fri, 22 Jan 2021 15:06:33 +0800
Subject: [PATCH] soundwire: bus: fix confusion on device used by pm_runtime
Git-commit: 973794e85610d9a716a897baa9007ff56e192826
Patch-mainline: v5.12-rc1
References: git-fixes

Intel stress-tests routinely report IO timeouts and invalid power
management transitions. Upon further analysis, we seem to be using the
wrong devices in pm_runtime calls.

Before reading and writing registers, we first need to make sure the
Slave is fully resumed. The existing code attempts to do such that,
however because of a confusion dating from 2017 and copy/paste, we
end-up resuming the parent only instead of resuming the codec device.

This can lead to accesses to the Slave registers while the bus is
still being configured and the Slave not enumerated, and as a result
IO errors occur.

This is a classic problem, similar confusions happened for HDaudio
between bus and codec device, leading to power management issues.

Fix by using the relevant device for all uses of pm_runtime functions.

Fixes: 60ee9be255712 ('soundwire: bus: add PM/no-PM versions of read/write functions')
Fixes: aa79293517b39 ('soundwire: bus: fix io error when processing alert event')
Fixes: 9d715fa005ebc ('soundwire: Add IO transfer')
Reported-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-9-yung-chuan.liao@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, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 45e9fc9f472a..ca12b6d6434d 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -515,16 +515,16 @@ int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 {
 	int ret;
 
-	ret = pm_runtime_get_sync(slave->bus->dev);
+	ret = pm_runtime_get_sync(&slave->dev);
 	if (ret < 0 && ret != -EACCES) {
-		pm_runtime_put_noidle(slave->bus->dev);
+		pm_runtime_put_noidle(&slave->dev);
 		return ret;
 	}
 
 	ret = sdw_nread_no_pm(slave, addr, count, val);
 
-	pm_runtime_mark_last_busy(slave->bus->dev);
-	pm_runtime_put(slave->bus->dev);
+	pm_runtime_mark_last_busy(&slave->dev);
+	pm_runtime_put(&slave->dev);
 
 	return ret;
 }
@@ -541,16 +541,16 @@ int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 {
 	int ret;
 
-	ret = pm_runtime_get_sync(slave->bus->dev);
+	ret = pm_runtime_get_sync(&slave->dev);
 	if (ret < 0 && ret != -EACCES) {
-		pm_runtime_put_noidle(slave->bus->dev);
+		pm_runtime_put_noidle(&slave->dev);
 		return ret;
 	}
 
 	ret = sdw_nwrite_no_pm(slave, addr, count, val);
 
-	pm_runtime_mark_last_busy(slave->bus->dev);
-	pm_runtime_put(slave->bus->dev);
+	pm_runtime_mark_last_busy(&slave->dev);
+	pm_runtime_put(&slave->dev);
 
 	return ret;
 }
@@ -1451,7 +1451,7 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 	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);
+		pm_runtime_put_noidle(&slave->dev);
 		return ret;
 	}
 
-- 
2.26.2