netdev - Re: LAN8720: RX errors / packet loss when using smsc PHY driver on i.MX6Q

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Message-ID: <CAOMZO5CLvDMgxi+VUVgiTy=TsK75QMYrTYZDEOzY4Y7eN=CRMw@mail.gmail.com>
Date: Sat, 15 Nov 2025 18:54:08 -0300
From: Fabio Estevam <festevam@...il.com>
To: Heiner Kallweit <hkallweit1@...il.com>
Cc: Russell King - ARM Linux <linux@...linux.org.uk>, edumazet <edumazet@...gle.com>, 
	netdev <netdev@...r.kernel.org>, Andrew Lunn <andrew@...n.ch>
Subject: Re: LAN8720: RX errors / packet loss when using smsc PHY driver on i.MX6Q

On Sat, Nov 15, 2025 at 6:26 PM Heiner Kallweit <hkallweit1@...il.com> wrote:

> smsc_phy_reset() does two things:
> 1. set PHY to "all capable" mode if in power-down
> 2. genphy_soft_reset()
>
> Again, as the genphy driver works fine for you, both parts should be optional.
> Check with part is causing the packet loss.

It is the genphy_soft_reset() that causes the packet loss.

If I comment it out like this, there is no packet loss:

--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -149,8 +149,7 @@ static int smsc_phy_reset(struct phy_device *phydev)
                phy_write(phydev, MII_LAN83C185_SPECIAL_MODES, rc);
        }

-       /* reset the phy */
-       return genphy_soft_reset(phydev);
+       return 0
 }