[PATCH net v2 0/4] net: dsa: realtek: use devm_mutex_init

[PATCH net v2 0/4] net: dsa: realtek: use devm_mutex_init

[Luiz Angelo Daros de Luca]

This series fixes mutex teardown in the Realtek DSA drivers.

With CONFIG_DEBUG_MUTEXES enabled, mutex_destroy() must be called before
the mutex is discarded. Using devm_mutex_init() lets the driver core
handle that automatically.

The changes are split into individual commits based on the feature that
introduced each lock to allow proper backports to stable trees.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
Changes in v2:
- Split the commit into individual commits for each mutex_init()
  introduction. 
- Add the error code to the rtl8365mb_stats_setup() error message.
- Link to v1: https://patch.msgid.link/20260718-realtek_mutext-v1-1-1cd7beb20ae6@gmail.com

To: Linus Walleij <linusw@kernel.org>
To: Alvin Šipraga <alsi@bang-olufsen.dk>
To: Andrew Lunn <andrew@lunn.ch>
To: Vladimir Oltean <olteanv@gmail.com>
To: "David S. Miller" <davem@davemloft.net>
To: Eric Dumazet <edumazet@google.com>
To: Jakub Kicinski <kuba@kernel.org>
To: Paolo Abeni <pabeni@redhat.com>
To: Michael Rasmussen <mir@bang-olufsen.dk>
To: Florian Fainelli <f.fainelli@gmail.com>
To: Luiz Angelo Daros de Luca <luizluca@gmail.com>
To: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

---
Luiz Angelo Daros de Luca (4):
      net: dsa: realtek: rtl8365mb: use devm_mutex_init for mib_lock
      net: dsa: realtek: use devm_mutex_init for regmap lock
      net: dsa: realtek: use devm_mutex_init for vlan_lock
      net: dsa: realtek: use devm_mutex_init for l2_lock

 drivers/net/dsa/realtek/rtl8365mb_main.c | 16 +++++++++++++---
 drivers/net/dsa/realtek/rtl83xx.c        | 14 +++++++++++---
 2 files changed, 24 insertions(+), 6 deletions(-)
---
base-commit: 4361bac9a4adf0e97639130c765669b41030e86e
change-id: 20260718-realtek_mutext-41a072e5cd24

Best regards,
--  
Luiz Angelo Daros de Luca <luizluca@gmail.com>

[PATCH net v2 1/4] net: dsa: realtek: rtl8365mb: use devm_mutex_init for mib_lock

[Luiz Angelo Daros de Luca]

With CONFIG_DEBUG_MUTEXES enabled, mutex_destroy() needs to be called
before the lock is discarded. Use devm_mutex_init() instead so the
cleanup is handled automatically.

Fixes: 4af2950c50c86 ("net: dsa: realtek-smi: add rtl8365mb subdriver for RTL8365MB-VC")
Reviewed-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/rtl8365mb_main.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/realtek/rtl8365mb_main.c b/drivers/net/dsa/realtek/rtl8365mb_main.c
index 5ac091bf93c9..aa05375b090a 100644
--- a/drivers/net/dsa/realtek/rtl8365mb_main.c
+++ b/drivers/net/dsa/realtek/rtl8365mb_main.c
@@ -1988,16 +1988,19 @@ static void rtl8365mb_get_stats64(struct dsa_switch *ds, int port,
 	spin_unlock(&p->stats_lock);
 }
 
-static void rtl8365mb_stats_setup(struct realtek_priv *priv)
+static int rtl8365mb_stats_setup(struct realtek_priv *priv)
 {
 	struct rtl8365mb *mb = priv->chip_data;
 	struct dsa_switch *ds = &priv->ds;
 	struct dsa_port *dp;
+	int ret;
 
 	/* Per-chip global mutex to protect MIB counter access, since doing
 	 * so requires accessing a series of registers in a particular order.
 	 */
-	mutex_init(&mb->mib_lock);
+	ret = devm_mutex_init(priv->dev, &mb->mib_lock);
+	if (ret)
+		return ret;
 
 	dsa_switch_for_each_available_port(dp, ds) {
 		struct rtl8365mb_port *p = &mb->ports[dp->index];
@@ -2010,6 +2013,8 @@ static void rtl8365mb_stats_setup(struct realtek_priv *priv)
 		 */
 		INIT_DELAYED_WORK(&p->mib_work, rtl8365mb_stats_poll);
 	}
+
+	return 0;
 }
 
 static void rtl8365mb_stats_teardown(struct realtek_priv *priv)
@@ -2567,7 +2572,12 @@ static int rtl8365mb_setup(struct dsa_switch *ds)
 	}
 
 	/* Start statistics counter polling */
-	rtl8365mb_stats_setup(priv);
+	ret = rtl8365mb_stats_setup(priv);
+	if (ret) {
+		dev_err(priv->dev, "failed to setup stats: %pe\n",
+			ERR_PTR(ret));
+		goto out_teardown_irq;
+	}
 
 	return 0;
 

-- 
2.55.0

[PATCH net v2 2/4] net: dsa: realtek: use devm_mutex_init for regmap lock

[Luiz Angelo Daros de Luca]

With CONFIG_DEBUG_MUTEXES enabled, mutex_destroy() needs to be called
before the lock is discarded. Use devm_mutex_init() instead so the
cleanup is handled automatically.

Fixes: 907e772f6f6de ("net: dsa: realtek: allow subdrivers to externally lock regmap")
Reviewed-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/rtl83xx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
index 71124ecca92f..9402bfe4f85a 100644
--- a/drivers/net/dsa/realtek/rtl83xx.c
+++ b/drivers/net/dsa/realtek/rtl83xx.c
@@ -156,7 +156,10 @@ rtl83xx_probe(struct device *dev,
 	if (!priv)
 		return ERR_PTR(-ENOMEM);
 
-	mutex_init(&priv->map_lock);
+	ret = devm_mutex_init(dev, &priv->map_lock);
+	if (ret)
+		return ERR_PTR(ret);
+
 	mutex_init(&priv->vlan_lock);
 	mutex_init(&priv->l2_lock);
 

-- 
2.55.0

[PATCH net v2 3/4] net: dsa: realtek: use devm_mutex_init for vlan_lock

[Luiz Angelo Daros de Luca]

With CONFIG_DEBUG_MUTEXES enabled, mutex_destroy() needs to be called
before the lock is discarded. Use devm_mutex_init() instead so the
cleanup is handled automatically.

Fixes: 9da2c8672f771 ("net: dsa: realtek: rtl8365mb: add VLAN support")
Reviewed-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/rtl83xx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
index 9402bfe4f85a..9f40afb19ab2 100644
--- a/drivers/net/dsa/realtek/rtl83xx.c
+++ b/drivers/net/dsa/realtek/rtl83xx.c
@@ -160,7 +160,10 @@ rtl83xx_probe(struct device *dev,
 	if (ret)
 		return ERR_PTR(ret);
 
-	mutex_init(&priv->vlan_lock);
+	ret = devm_mutex_init(dev, &priv->vlan_lock);
+	if (ret)
+		return ERR_PTR(ret);
+
 	mutex_init(&priv->l2_lock);
 
 	rc.lock_arg = priv;

-- 
2.55.0

[PATCH net v2 4/4] net: dsa: realtek: use devm_mutex_init for l2_lock

[Luiz Angelo Daros de Luca]

With CONFIG_DEBUG_MUTEXES enabled, mutex_destroy() needs to be called
before the lock is discarded. Use devm_mutex_init() instead so the
cleanup is handled automatically.

Fixes: 336e3e4a1ab37 ("net: dsa: realtek: rtl8365mb: add FDB support")
Reviewed-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/rtl83xx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
index 9f40afb19ab2..9dd50b20c000 100644
--- a/drivers/net/dsa/realtek/rtl83xx.c
+++ b/drivers/net/dsa/realtek/rtl83xx.c
@@ -164,7 +164,9 @@ rtl83xx_probe(struct device *dev,
 	if (ret)
 		return ERR_PTR(ret);
 
-	mutex_init(&priv->l2_lock);
+	ret = devm_mutex_init(dev, &priv->l2_lock);
+	if (ret)
+		return ERR_PTR(ret);
 
 	rc.lock_arg = priv;
 	priv->map = devm_regmap_init(dev, NULL, priv, &rc);

-- 
2.55.0