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From: Ansuel Smith <ansuelsmth@gmail.com>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ansuel Smith <ansuelsmth@gmail.com>, Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH net-next v4 21/28] net: dsa: qca8k: dsa: qca8k: protect MASTER busy_wait with mdio mutex
Date: Sat,  8 May 2021 02:29:11 +0200	[thread overview]
Message-ID: <20210508002920.19945-21-ansuelsmth@gmail.com> (raw)
In-Reply-To: <20210508002920.19945-1-ansuelsmth@gmail.com>

MDIO_MASTER operation have a dedicated busy wait that is not protected
by the mdio mutex. This can cause situation where the MASTER operation
is done and a normal operation is executed between the MASTER read/write
and the MASTER busy_wait. Rework the qca8k_mdio_read/write function to
address this issue by binding the lock for the whole MASTER operation
and not only the mdio read/write common operation.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca8k.c | 68 +++++++++++++++++++++++++++++++++--------
 1 file changed, 55 insertions(+), 13 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 2e0d2f918efe..e272ccaaa7f6 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -639,9 +639,32 @@ qca8k_port_to_phy(int port)
 	return port - 1;
 }
 
+static int
+qca8k_mdio_busy_wait(struct qca8k_priv *priv, u32 reg, u32 mask)
+{
+	u16 r1, r2, page;
+	u32 val;
+	int ret;
+
+	qca8k_split_addr(reg, &r1, &r2, &page);
+
+	ret = read_poll_timeout(qca8k_mii_read32, val, !(val & mask), 0,
+				QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC, false,
+				priv->bus, 0x10 | r2, r1);
+
+	/* Check if qca8k_read has failed for a different reason
+	 * before returnting -ETIMEDOUT
+	 */
+	if (ret < 0 && val < 0)
+		return val;
+
+	return ret;
+}
+
 static int
 qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data)
 {
+	u16 r1, r2, page;
 	u32 phy, val;
 	int ret;
 
@@ -657,12 +680,21 @@ qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data)
 	      QCA8K_MDIO_MASTER_REG_ADDR(regnum) |
 	      QCA8K_MDIO_MASTER_DATA(data);
 
-	ret = qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val);
+	qca8k_split_addr(QCA8K_MDIO_MASTER_CTRL, &r1, &r2, &page);
+
+	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
+
+	ret = qca8k_set_page(priv->bus, page);
 	if (ret)
-		return ret;
+		goto exit;
+
+	qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val);
+
+	ret = qca8k_mdio_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
+				   QCA8K_MDIO_MASTER_BUSY);
 
-	ret = qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
-			      QCA8K_MDIO_MASTER_BUSY);
+exit:
+	mutex_unlock(&priv->bus->mdio_lock);
 
 	/* even if the busy_wait timeouts try to clear the MASTER_EN */
 	qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL,
@@ -674,6 +706,7 @@ qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data)
 static int
 qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum)
 {
+	u16 r1, r2, page;
 	u32 phy, val;
 	int ret;
 
@@ -688,21 +721,30 @@ qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum)
 	      QCA8K_MDIO_MASTER_READ | QCA8K_MDIO_MASTER_PHY_ADDR(phy) |
 	      QCA8K_MDIO_MASTER_REG_ADDR(regnum);
 
-	ret = qca8k_write(priv, QCA8K_MDIO_MASTER_CTRL, val);
-	if (ret)
-		return ret;
+	qca8k_split_addr(QCA8K_MDIO_MASTER_CTRL, &r1, &r2, &page);
+
+	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
 
-	ret = qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
-			      QCA8K_MDIO_MASTER_BUSY);
+	ret = qca8k_set_page(priv->bus, page);
 	if (ret)
-		return ret;
+		goto exit;
 
-	val = qca8k_read(priv, QCA8K_MDIO_MASTER_CTRL);
-	if (val < 0)
-		return val;
+	qca8k_mii_write32(priv->bus, 0x10 | r2, r1, val);
+
+	ret = qca8k_mdio_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
+				   QCA8K_MDIO_MASTER_BUSY);
+	if (ret)
+		goto exit;
 
+	val = qca8k_mii_read32(priv->bus, 0x10 | r2, r1);
 	val &= QCA8K_MDIO_MASTER_DATA_MASK;
 
+exit:
+	mutex_unlock(&priv->bus->mdio_lock);
+
+	if (val >= 0)
+		val &= QCA8K_MDIO_MASTER_DATA_MASK;
+
 	/* even if the busy_wait timeouts try to clear the MASTER_EN */
 	qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL,
 			QCA8K_MDIO_MASTER_EN);
-- 
2.30.2


  parent reply	other threads:[~2021-05-08  0:31 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-08  0:28 [RFC PATCH net-next v4 01/28] net: mdio: ipq8064: clean whitespaces in define Ansuel Smith
2021-05-08  0:28 ` [RFC PATCH net-next v4 02/28] net: mdio: ipq8064: add regmap config to disable REGCACHE Ansuel Smith
2021-05-08 15:46   ` Florian Fainelli
2021-05-08  0:28 ` [RFC PATCH net-next v4 03/28] net: mdio: ipq8064: enlarge sleep after read/write operation Ansuel Smith
2021-05-08 15:53   ` Florian Fainelli
2021-05-08  0:28 ` [RFC PATCH net-next v4 04/28] net: dsa: qca8k: change simple print to dev variant Ansuel Smith
2021-05-08 15:47   ` Florian Fainelli
2021-05-08  0:28 ` [RFC PATCH net-next v4 05/28] net: dsa: qca8k: use iopoll macro for qca8k_busy_wait Ansuel Smith
2021-05-08 17:38   ` Andrew Lunn
2021-05-08  0:28 ` [RFC PATCH net-next v4 06/28] net: dsa: qca8k: improve qca8k read/write/rmw bus access Ansuel Smith
2021-05-08 17:39   ` Andrew Lunn
2021-05-08  0:28 ` [RFC PATCH net-next v4 07/28] net: dsa: qca8k: handle qca8k_set_page errors Ansuel Smith
2021-05-08 17:40   ` Andrew Lunn
2021-05-08  0:28 ` [RFC PATCH net-next v4 08/28] net: dsa: qca8k: handle error with qca8k_read operation Ansuel Smith
2021-05-08 17:46   ` Andrew Lunn
2021-05-08  0:28 ` [RFC PATCH net-next v4 09/28] net: dsa: qca8k: handle error with qca8k_write operation Ansuel Smith
2021-05-08 17:47   ` Andrew Lunn
2021-05-08  0:29 ` [RFC PATCH net-next v4 10/28] net: dsa: qca8k: handle error with qca8k_rmw operation Ansuel Smith
2021-05-08 17:59   ` Andrew Lunn
2021-05-08  0:29 ` [RFC PATCH net-next v4 11/28] net: dsa: qca8k: handle error from qca8k_busy_wait Ansuel Smith
2021-05-08 17:59   ` Andrew Lunn
2021-05-08  0:29 ` [RFC PATCH net-next v4 12/28] net: dsa: qca8k: add support for qca8327 switch Ansuel Smith
2021-05-08 15:47   ` Florian Fainelli
2021-05-08  0:29 ` [RFC PATCH net-next v4 13/28] devicetree: net: dsa: qca8k: Document new compatible qca8327 Ansuel Smith
2021-05-08 15:47   ` Florian Fainelli
2021-05-08  0:29 ` [RFC PATCH net-next v4 14/28] net: dsa: qca8k: add priority tweak to qca8337 switch Ansuel Smith
2021-05-08  0:29 ` [RFC PATCH net-next v4 15/28] net: dsa: qca8k: limit port5 delay to qca8337 Ansuel Smith
2021-05-08  0:29 ` [RFC PATCH net-next v4 16/28] net: dsa: qca8k: add GLOBAL_FC settings needed for qca8327 Ansuel Smith
2021-05-08  0:29 ` [RFC PATCH net-next v4 17/28] net: dsa: qca8k: add support for switch rev Ansuel Smith
2021-05-08 15:48   ` Florian Fainelli
2021-05-08  0:29 ` [RFC PATCH net-next v4 18/28] net: dsa: qca8k: add ethernet-ports fallback to setup_mdio_bus Ansuel Smith
2021-05-08 18:07   ` Andrew Lunn
2021-05-08  0:29 ` [RFC PATCH net-next v4 19/28] net: dsa: qca8k: make rgmii delay configurable Ansuel Smith
2021-05-08 18:12   ` Andrew Lunn
2021-05-08 23:58     ` Ansuel Smith
2021-05-09  1:07       ` Andrew Lunn
2021-05-09  1:17         ` Ansuel Smith
2021-05-09  1:27           ` Andrew Lunn
2021-05-08  0:29 ` [RFC PATCH net-next v4 20/28] net: dsa: qca8k: clear MASTER_EN after phy read/write Ansuel Smith
2021-05-08  0:29 ` Ansuel Smith [this message]
2021-05-08  0:29 ` [RFC PATCH net-next v4 22/28] net: dsa: qca8k: enlarge mdio delay and timeout Ansuel Smith
2021-05-08  0:29 ` [RFC PATCH net-next v4 23/28] net: dsa: register of_mdiobus if a mdio node is declared Ansuel Smith
2021-05-08  4:36   ` Florian Fainelli
2021-05-08  0:29 ` [RFC PATCH net-next v4 24/28] devicetree: net: dsa: Document use of mdio node inside switch node Ansuel Smith
2021-05-10 14:01   ` Rob Herring
2021-05-08  0:29 ` [RFC PATCH net-next v4 25/28] net: dsa: qca8k: add support for internal phy Ansuel Smith
2021-05-08  0:29 ` [RFC PATCH net-next v4 26/28] net: dsa: permit driver to provide custom phy_mii_mask for slave mdiobus Ansuel Smith
2021-05-08 15:52   ` Florian Fainelli
2021-05-08 16:29     ` Ansuel Smith
2021-05-08  0:29 ` [RFC PATCH net-next v4 27/28] net: dsa: qca8k: pass switch_revision info to phy dev_flags Ansuel Smith
2021-05-08 15:49   ` Florian Fainelli
2021-05-08  0:29 ` [RFC PATCH net-next v4 28/28] net: phy: add qca8k driver for qca8k switch internal PHY Ansuel Smith
2021-05-08  4:35   ` DENG Qingfang
2021-05-08 11:30     ` Ansuel Smith
2021-05-08 15:45       ` Florian Fainelli
2021-05-08 15:45 ` [RFC PATCH net-next v4 01/28] net: mdio: ipq8064: clean whitespaces in define Florian Fainelli
2021-05-08 15:57 ` Joe Perches
2021-05-08 18:02 ` Andrew Lunn
2021-05-08 18:05   ` Ansuel Smith
2021-05-15 17:00     ` Jonathan McDowell
2021-05-15 17:03       ` Florian Fainelli
2021-05-15 17:30       ` Ansuel Smith
2021-05-15 18:08         ` Jonathan McDowell
2021-05-15 18:20           ` Ansuel Smith
2021-05-15 19:40             ` Jonathan McDowell
2021-05-15 19:47               ` Ansuel Smith
2021-05-15 23:52                 ` Andrew Lunn
2021-05-16  0:23                   ` Ansuel Smith
2021-05-16  9:37                     ` Jonathan McDowell
2021-05-16  9:49         ` Jonathan McDowell
2021-05-16 10:12           ` Jonathan McDowell

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