From nobody Wed Dec 24 19:51:22 2025 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16FA87691E for ; Wed, 24 Jan 2024 12:33:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706099606; cv=none; b=ZqKBMCfBbIB+8RfVGGEqRgiWUVa0rOzF7TtgBLPivwCFLNgz/iYNBCCGuw8ROTZjs6SHTNwMhHJZ0yXaRonbcOe+iG98MnLeWDOAjjpJ0aedxEnSUQD9hrQk2pV4irqo30N8FLKOYupPnFwAEoIWipnuStNdWKTkLhpaQsVRjUU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706099606; c=relaxed/simple; bh=4aPJJecww9GOMWDNhV+Os9xjhao/fFA0y9gRuox/9/U=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OBn68uCeydEpJLyQ+QYOEOTqvREOuZmxJB7eU66sAXCmrU9kJc9NhfkJydAUZdo2Th7JlC+gQeg/NcOQYLN0D6k1L/J3AoLtOyr7j5nhTBeWzBNBTs9DairfT6yE5+gTnA7khEh3q4MvSUwsDG17yBNykTOJEzsKGKsFEvG+8zo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rScRR-0000I1-6l; Wed, 24 Jan 2024 13:33:17 +0100 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1rScRP-0023bS-Ax; Wed, 24 Jan 2024 13:33:15 +0100 Received: from ore by dude04.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1rScRP-0035Ap-0o; Wed, 24 Jan 2024 13:33:15 +0100 From: Oleksij Rempel To: "David S. Miller" , Andrew Lunn , Eric Dumazet , Florian Fainelli , Jakub Kicinski , Paolo Abeni , Vladimir Oltean , Woojung Huh , Arun Ramadoss Cc: Oleksij Rempel , Vladimir Oltean , kernel@pengutronix.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, UNGLinuxDriver@microchip.com, =?UTF-8?q?S=C3=B8ren=20Andersen?= Subject: [PATCH net-next v4 3/3] net: dsa: microchip: implement PHY loopback configuration for KSZ8794 and KSZ8873 Date: Wed, 24 Jan 2024 13:33:14 +0100 Message-Id: <20240124123314.734815-4-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240124123314.734815-1-o.rempel@pengutronix.de> References: <20240124123314.734815-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Correct the PHY loopback bit handling in the ksz8_w_phy_bmcr and ksz8_r_phy_bmcr functions for KSZ8794 and KSZ8873 variants in the ksz8795 driver. Previously, the code erroneously used Bit 7 of port register 0xD for both chip variants, which is actually for LED configuration. This update ensures the correct registers and bits are used for the PHY loopback feature: - For KSZ8794: Use 0xF / Bit 7. - For KSZ8873: Use 0xD / Bit 0. The lack of loopback support was seen on KSZ8873 system by using "ethtool -t lanX". After this patch, the ethtool selftest will work, but only if port is not part of a bridge. Signed-off-by: Oleksij Rempel Reviewed-by: Vladimir Oltean Acked-by: Arun Ramadoss --- drivers/net/dsa/microchip/ksz8795.c | 76 ++++++++++++++++++++++--- drivers/net/dsa/microchip/ksz8795_reg.h | 1 + 2 files changed, 70 insertions(+), 7 deletions(-) diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchi= p/ksz8795.c index 51e0194453df..50351cef6ca5 100644 --- a/drivers/net/dsa/microchip/ksz8795.c +++ b/drivers/net/dsa/microchip/ksz8795.c @@ -632,6 +632,57 @@ static void ksz8_w_vlan_table(struct ksz_device *dev, = u16 vid, u16 vlan) ksz8_w_table(dev, TABLE_VLAN, addr, buf); } =20 +/** + * ksz879x_get_loopback - KSZ879x specific function to get loopback + * configuration status for a specific port + * @dev: Pointer to the device structure + * @port: Port number to query + * @val: Pointer to store the result + * + * This function reads the SMI registers to determine whether loopback mode + * is enabled for a specific port. + * + * Return: 0 on success, error code on failure. + */ +static int ksz879x_get_loopback(struct ksz_device *dev, u16 port, + u16 *val) +{ + u8 stat3; + int ret; + + ret =3D ksz_pread8(dev, port, REG_PORT_STATUS_3, &stat3); + if (ret) + return ret; + + if (stat3 & PORT_PHY_LOOPBACK) + *val |=3D BMCR_LOOPBACK; + + return 0; +} + +/** + * ksz879x_set_loopback - KSZ879x specific function to set loopback mode = for + * a specific port + * @dev: Pointer to the device structure. + * @port: Port number to modify. + * @val: Value indicating whether to enable or disable loopback mode. + * + * This function translates loopback bit of the BMCR register into the + * corresponding hardware register bit value and writes it to the SMI inte= rface. + * + * Return: 0 on success, error code on failure. + */ +static int ksz879x_set_loopback(struct ksz_device *dev, u16 port, u16 val) +{ + u8 stat3 =3D 0; + + if (val & BMCR_LOOPBACK) + stat3 |=3D PORT_PHY_LOOPBACK; + + return ksz_prmw8(dev, port, REG_PORT_STATUS_3, PORT_PHY_LOOPBACK, + stat3); +} + /** * ksz8_r_phy_ctrl - Translates and reads from the SMI interface to a MIIM= PHY * Control register (Reg. 31). @@ -731,16 +782,20 @@ static int ksz8_r_phy_bmcr(struct ksz_device *dev, u1= 6 port, u16 *val) if (ret) return ret; =20 - if (restart & PORT_PHY_LOOPBACK) - *val |=3D BMCR_LOOPBACK; - if (ctrl & PORT_FORCE_100_MBIT) *val |=3D BMCR_SPEED100; =20 if (ksz_is_ksz88x3(dev)) { + if (restart & KSZ8873_PORT_PHY_LOOPBACK) + *val |=3D BMCR_LOOPBACK; + if ((ctrl & PORT_AUTO_NEG_ENABLE)) *val |=3D BMCR_ANENABLE; } else { + ret =3D ksz879x_get_loopback(dev, port, val); + if (ret) + return ret; + if (!(ctrl & PORT_AUTO_NEG_DISABLE)) *val |=3D BMCR_ANENABLE; } @@ -1001,8 +1056,7 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u1= 6 port, u16 val) =20 restart =3D 0; restart_mask =3D PORT_LED_OFF | PORT_TX_DISABLE | PORT_AUTO_NEG_RESTART | - PORT_POWER_DOWN | PORT_AUTO_MDIX_DISABLE | PORT_FORCE_MDIX | - PORT_PHY_LOOPBACK; + PORT_POWER_DOWN | PORT_AUTO_MDIX_DISABLE | PORT_FORCE_MDIX; =20 if (val & KSZ886X_BMCR_DISABLE_LED) restart |=3D PORT_LED_OFF; @@ -1022,8 +1076,16 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u= 16 port, u16 val) if (val & KSZ886X_BMCR_FORCE_MDI) restart |=3D PORT_FORCE_MDIX; =20 - if (val & BMCR_LOOPBACK) - restart |=3D PORT_PHY_LOOPBACK; + if (ksz_is_ksz88x3(dev)) { + restart_mask |=3D KSZ8873_PORT_PHY_LOOPBACK; + + if (val & BMCR_LOOPBACK) + restart |=3D KSZ8873_PORT_PHY_LOOPBACK; + } else { + ret =3D ksz879x_set_loopback(dev, port, val); + if (ret) + return ret; + } =20 return ksz_prmw8(dev, port, regs[P_NEG_RESTART_CTRL], restart_mask, restart); diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/micr= ochip/ksz8795_reg.h index beca974e0171..7c9341ef73b0 100644 --- a/drivers/net/dsa/microchip/ksz8795_reg.h +++ b/drivers/net/dsa/microchip/ksz8795_reg.h @@ -265,6 +265,7 @@ #define PORT_AUTO_MDIX_DISABLE BIT(2) #define PORT_FORCE_MDIX BIT(1) #define PORT_MAC_LOOPBACK BIT(0) +#define KSZ8873_PORT_PHY_LOOPBACK BIT(0) =20 #define REG_PORT_1_STATUS_2 0x1E #define REG_PORT_2_STATUS_2 0x2E --=20 2.39.2