From: Thanh Quan Date: Mon, 27 Oct 2025 14:02:43 +0000 (+0100) Subject: net: phy: dp83869: fix STRAP_OPMODE bitmask X-Git-Tag: v6.18-rc4~24^2~5 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=298574936a6c4ebbe655e15d971ddb1a96c7dc0b;p=thirdparty%2Fkernel%2Fstable.git net: phy: dp83869: fix STRAP_OPMODE bitmask According to the TI DP83869HM datasheet Revision D (June 2025), section 7.6.1.41 STRAP_STS Register, the STRAP_OPMODE bitmask is bit [11:9]. Fix this. In case the PHY is auto-detected via PHY ID registers, or not described in DT, or, in case the PHY is described in DT but the optional DT property "ti,op-mode" is not present, then the driver reads out the PHY functional mode (RGMII, SGMII, ...) from hardware straps. Currently, all upstream users of this PHY specify both DT compatible string "ethernet-phy-id2000.a0f1" and ti,op-mode = property, therefore it seems no upstream users are affected by this bug. The driver currently interprets bits [2:0] of STRAP_STS register as PHY functional mode. Those bits are controlled by ANEG_DIS, ANEGSEL_0 straps and an always-zero reserved bit. Systems that use RGMII-to-Copper functional mode are unlikely to disable auto-negotiation via ANEG_DIS strap, or change auto-negotiation behavior via ANEGSEL_0 strap. Therefore, even with this bug in place, the STRAP_STS register content is likely going to be interpreted by the driver as RGMII-to-Copper mode. However, for a system with PHY functional mode strapping set to other mode than RGMII-to-Copper, the driver is likely to misinterpret the strapping as RGMII-to-Copper and misconfigure the PHY. For example, on a system with SGMII-to-Copper strapping, the STRAP_STS register reads as 0x0c20, but the PHY ends up being configured for incompatible RGMII-to-Copper mode. Fixes: 0eaf8ccf2047 ("net: phy: dp83869: Set opmode from straps") Reviewed-by: Andrew Lunn Signed-off-by: Thanh Quan Signed-off-by: Hai Pham Signed-off-by: Marek Vasut # Port from U-Boot to Linux Link: https://patch.msgid.link/20251027140320.8996-1-marek.vasut+renesas@mailbox.org Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/phy/dp83869.c b/drivers/net/phy/dp83869.c index a2cd1cc35cde..1f381d7b13ff 100644 --- a/drivers/net/phy/dp83869.c +++ b/drivers/net/phy/dp83869.c @@ -84,7 +84,7 @@ #define DP83869_CLK_DELAY_DEF 7 /* STRAP_STS1 bits */ -#define DP83869_STRAP_OP_MODE_MASK GENMASK(2, 0) +#define DP83869_STRAP_OP_MODE_MASK GENMASK(11, 9) #define DP83869_STRAP_STS1_RESERVED BIT(11) #define DP83869_STRAP_MIRROR_ENABLED BIT(12) @@ -528,7 +528,7 @@ static int dp83869_set_strapped_mode(struct phy_device *phydev) if (val < 0) return val; - dp83869->mode = val & DP83869_STRAP_OP_MODE_MASK; + dp83869->mode = FIELD_GET(DP83869_STRAP_OP_MODE_MASK, val); return 0; }