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From:   Oleksij Rempel <o.rempel@pengutronix.de>
To:     "David S. Miller" <davem@davemloft.net>,
        Andrew Lunn <andrew@lunn.ch>,
        Eric Dumazet <edumazet@google.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Woojung Huh <woojung.huh@microchip.com>,
        Arun Ramadoss <arun.ramadoss@microchip.com>
Cc:     Oleksij Rempel <o.rempel@pengutronix.de>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        UNGLinuxDriver@microchip.com,
        "Russell King (Oracle)" <linux@armlinux.org.uk>
Subject: [PATCH net-next v1 1/5] net: dsa: microchip: improving error handling for 8-bit register RMW operations
Date:   Wed, 24 May 2023 14:32:16 +0200
Message-Id: <20230524123220.2481565-2-o.rempel@pengutronix.de>
In-Reply-To: <20230524123220.2481565-1-o.rempel@pengutronix.de>
References: <20230524123220.2481565-1-o.rempel@pengutronix.de>
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This patch refines the error handling mechanism for 8-bit register
read-modify-write operations. In case of a failure, it now logs an error
message detailing the problematic offset. This enhancement aids in
debugging by providing more precise information when these operations
encounter issues.

Furthermore, the ksz_prmw8() function has been updated to return error
values rather than void, enabling calling functions to appropriately
respond to errors.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/dsa/microchip/ksz_common.h | 28 ++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 8abecaf6089e..b86f1e27a0c3 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -508,7 +508,14 @@ static inline int ksz_write64(struct ksz_device *dev, u32 reg, u64 value)
 
 static inline int ksz_rmw8(struct ksz_device *dev, int offset, u8 mask, u8 val)
 {
-	return regmap_update_bits(dev->regmap[0], offset, mask, val);
+	int ret;
+
+	ret = regmap_update_bits(dev->regmap[0], offset, mask, val);
+	if (ret)
+		dev_err(dev->dev, "can't rmw 8bit reg 0x%x: %pe\n", offset,
+			ERR_PTR(ret));
+
+	return ret;
 }
 
 static inline int ksz_pread8(struct ksz_device *dev, int port, int offset,
@@ -549,12 +556,21 @@ static inline int ksz_pwrite32(struct ksz_device *dev, int port, int offset,
 			   data);
 }
 
-static inline void ksz_prmw8(struct ksz_device *dev, int port, int offset,
-			     u8 mask, u8 val)
+static inline int ksz_prmw8(struct ksz_device *dev, int port, int offset,
+			    u8 mask, u8 val)
 {
-	regmap_update_bits(dev->regmap[0],
-			   dev->dev_ops->get_port_addr(port, offset),
-			   mask, val);
+	int ret;
+
+	ret = regmap_update_bits(dev->regmap[0],
+				 dev->dev_ops->get_port_addr(port, offset),
+				 mask, val);
+	if (ret)
+		dev_err(dev->dev, "can't rmw 8bit reg 0x%x: %pe\n",
+			dev->dev_ops->get_port_addr(port, offset),
+			ERR_PTR(ret));
+
+	return ret;
+
 }
 
 static inline void ksz_regmap_lock(void *__mtx)
-- 
2.39.2