diff mbox series

[net-next,v1,3/7] net: usb: lan78xx: Improve error handling for PHY init path

Message ID 20250108121341.2689130-4-o.rempel@pengutronix.de (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Convert LAN78xx to PHYLINK | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: linux-usb@vger.kernel.org
netdev/build_clang success Errors and warnings before: 3 this patch: 2
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 3
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Oleksij Rempel Jan. 8, 2025, 12:13 p.m. UTC 
Make sure existing return values are actually used.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/usb/lan78xx.c | 58 +++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 18 deletions(-)

Comments

Russell King (Oracle) Jan. 8, 2025, 12:52 p.m. UTC | #1 
On Wed, Jan 08, 2025 at 01:13:37PM +0100, Oleksij Rempel wrote:
>  	phydev = phy_find_first(dev->mdiobus);
>  	if (!phydev) {
>  		netdev_dbg(dev->net, "PHY Not Found!! Registering Fixed PHY\n");
>  		phydev = fixed_phy_register(PHY_POLL, &fphy_status, NULL);
> -		if (IS_ERR(phydev)) {
> +		if (PTR_ERR_OR_ZERO(phydev)) {

Even though I've said to use phylink's fixed-phy support, I'm wondering
about this entire hunk.

>  			netdev_err(dev->net, "No PHY/fixed_PHY found\n");
> -			return NULL;
> +			if (IS_ERR(phydev))
> +				return phydev;
> +			else
> +				return ERR_PTR(-ENODEV);

When does fixed_phy_register() return NULL?

If there's no fixed-phy support enabled, then you get an ENODEV error
pointer. If support is enabled, then you may get an error pointer
or a valid phy_device structure. I can't see any case where it returns
NULL. So, I think this hunk is redundant.
diff mbox series

Patch

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 3d0097d07bcd..dde127d18a07 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2574,22 +2574,24 @@  static const struct phylink_mac_ops lan78xx_phylink_mac_ops = {
 
 static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
 {
-	u32 buf;
-	int ret;
 	struct fixed_phy_status fphy_status = {
 		.link = 1,
 		.speed = SPEED_1000,
 		.duplex = DUPLEX_FULL,
 	};
 	struct phy_device *phydev;
+	int ret;
 
 	phydev = phy_find_first(dev->mdiobus);
 	if (!phydev) {
 		netdev_dbg(dev->net, "PHY Not Found!! Registering Fixed PHY\n");
 		phydev = fixed_phy_register(PHY_POLL, &fphy_status, NULL);
-		if (IS_ERR(phydev)) {
+		if (PTR_ERR_OR_ZERO(phydev)) {
 			netdev_err(dev->net, "No PHY/fixed_PHY found\n");
-			return NULL;
+			if (IS_ERR(phydev))
+				return phydev;
+			else
+				return ERR_PTR(-ENODEV);
 		}
 
 		dev->fixed_phy = phydev;
@@ -2597,24 +2599,34 @@  static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
 		phydev->interface = PHY_INTERFACE_MODE_RGMII;
 		ret = lan78xx_write_reg(dev, MAC_RGMII_ID,
 					MAC_RGMII_ID_TXC_DELAY_EN_);
+		if (ret < 0)
+			return ERR_PTR(ret);
+
 		ret = lan78xx_write_reg(dev, RGMII_TX_BYP_DLL, 0x3D00);
-		ret = lan78xx_read_reg(dev, HW_CFG, &buf);
-		buf |= HW_CFG_CLK125_EN_;
-		buf |= HW_CFG_REFCLK25_EN_;
-		ret = lan78xx_write_reg(dev, HW_CFG, buf);
+		if (ret < 0)
+			return ERR_PTR(ret);
+
+		ret = lan78xx_update_reg(dev, HW_CFG, HW_CFG_CLK125_EN_ |
+					 HW_CFG_REFCLK25_EN_,
+					 HW_CFG_CLK125_EN_ | HW_CFG_REFCLK25_EN_);
+		if (ret < 0)
+			return ERR_PTR(ret);
 	} else {
 		if (!phydev->drv) {
 			netdev_err(dev->net, "no PHY driver found\n");
-			return NULL;
+			return ERR_PTR(-ENODEV);
 		}
 		phydev->interface = PHY_INTERFACE_MODE_RGMII_ID;
 		/* The PHY driver is responsible to configure proper RGMII
 		 * interface delays. Disable RGMII delays on MAC side.
 		 */
-		lan78xx_write_reg(dev, MAC_RGMII_ID, 0);
+		ret = lan78xx_write_reg(dev, MAC_RGMII_ID, 0);
+		if (ret < 0)
+			return ERR_PTR(ret);
 
 		phydev->is_internal = false;
 	}
+
 	return phydev;
 }
 
@@ -2663,9 +2675,9 @@  static int lan78xx_phy_init(struct lan78xx_net *dev)
 	switch (dev->chipid) {
 	case ID_REV_CHIP_ID_7801_:
 		phydev = lan7801_phy_init(dev);
-		if (!phydev) {
+		if (IS_ERR(phydev)) {
 			netdev_err(dev->net, "lan7801: PHY Init Failed");
-			return -EIO;
+			return PTR_ERR(phydev);
 		}
 		break;
 
@@ -2674,7 +2686,7 @@  static int lan78xx_phy_init(struct lan78xx_net *dev)
 		phydev = phy_find_first(dev->mdiobus);
 		if (!phydev) {
 			netdev_err(dev->net, "no PHY found\n");
-			return -EIO;
+			return -ENODEV;
 		}
 		phydev->is_internal = true;
 		phydev->interface = PHY_INTERFACE_MODE_INTERNAL;
@@ -2682,7 +2694,7 @@  static int lan78xx_phy_init(struct lan78xx_net *dev)
 
 	default:
 		netdev_err(dev->net, "Unknown CHIP ID found\n");
-		return -EIO;
+		return -ENODEV;
 	}
 
 	/* if phyirq is not set, use polling mode in phylib */
@@ -2696,10 +2708,15 @@  static int lan78xx_phy_init(struct lan78xx_net *dev)
 	if (ret) {
 		netdev_err(dev->net, "can't attach PHY to %s, error %pe\n",
 			   dev->mdiobus->id, ERR_PTR(ret));
-		return -EIO;
+		return ret;
 	}
 
-	phy_suspend(phydev);
+	ret = phy_suspend(phydev);
+	if (ret) {
+		netdev_err(dev->net, "can't suspend PHY, error %pe\n",
+			   ERR_PTR(ret));
+		return ret;
+	}
 
 	phy_support_eee(phydev);
 
@@ -2712,7 +2729,10 @@  static int lan78xx_phy_init(struct lan78xx_net *dev)
 						      sizeof(u32));
 		if (len >= 0) {
 			/* Ensure the appropriate LEDs are enabled */
-			lan78xx_read_reg(dev, HW_CFG, &reg);
+			ret = lan78xx_read_reg(dev, HW_CFG, &reg);
+			if (ret < 0)
+				return ret;
+
 			reg &= ~(HW_CFG_LED0_EN_ |
 				 HW_CFG_LED1_EN_ |
 				 HW_CFG_LED2_EN_ |
@@ -2721,7 +2741,9 @@  static int lan78xx_phy_init(struct lan78xx_net *dev)
 				(len > 1) * HW_CFG_LED1_EN_ |
 				(len > 2) * HW_CFG_LED2_EN_ |
 				(len > 3) * HW_CFG_LED3_EN_;
-			lan78xx_write_reg(dev, HW_CFG, reg);
+			ret = lan78xx_write_reg(dev, HW_CFG, reg);
+			if (ret < 0)
+				return ret;
 		}
 	}