From nobody Sun Feb 8 04:18:15 2026 Received: from pidgin.makrotopia.org (pidgin.makrotopia.org [185.142.180.65]) (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 AE2C8214A97; Sun, 1 Feb 2026 03:42:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.142.180.65 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769917346; cv=none; b=eImPpqSDW2QMUAaglYv1Za9eO7v3cTW5b0DNVJjEBNnB/lxcUB1upi5bwNiNLSDEpnPNyczPD2PEqX9Bdsy5BuhM6ckyWvHvGO2JQMsRwe7c+cJJhdSRT2kRL98di2c2FtChoJBqrtMt6QjGiThVXuj+bGXBpJiaqBL53Aq6Q1A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769917346; c=relaxed/simple; bh=y5+QMwEDBy51k3wsErYHXEtqjXeGgkIxQaoB/RxTjzo=; h=Date:From:To:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Vbn5ZDQ9ZWJ2Q1YvnEJF0lFmG4tICsTYgnGacMkhSlv/jhkY9audIEp6J0MrxVNqrZz3A+FE1RAhsWlJFGekRwYPauCCOhGoZrZ3K4r/2doIUCObls0XlhdneoseVyhepJsAV8wX0MN3XshMFw1/q9hm6tGB1pVs1Ua/jhBzYj4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org; spf=pass smtp.mailfrom=makrotopia.org; arc=none smtp.client-ip=185.142.180.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=makrotopia.org Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.99) (envelope-from ) id 1vmOLt-000000002XJ-2EXk; Sun, 01 Feb 2026 03:42:21 +0000 Date: Sun, 1 Feb 2026 03:42:18 +0000 From: Daniel Golle To: Hauke Mehrtens , Andrew Lunn , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v3 3/3] net: dsa: mxl-gsw1xx: validate chip ID Message-ID: <3194d3d3bb0b51f08755d392e1fdf7bb6dc49608.1769916962.git.daniel@makrotopia.org> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" No check for actually present hardware is being performed in the probe function of the mxl-gsw1xx switch driver. So even if the switch isn't present at the configured MDIO bus address the driver wrongly tells the user that a "GSWIP version 0 mod 0" was found, outputting errors about PHY capabilities not matching. Read and validate the chip MANU_ID and PNUM_ID registers and output information while probing, but return an error and abort probing in case the hardware is not actually present. Signed-off-by: Daniel Golle --- v3: no changes v2: no changes drivers/net/dsa/lantiq/mxl-gsw1xx.c | 27 ++++++++++++++++++++++++++- drivers/net/dsa/lantiq/mxl-gsw1xx.h | 9 +++++++++ 2 files changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/net/dsa/lantiq/mxl-gsw1xx.c b/drivers/net/dsa/lantiq/m= xl-gsw1xx.c index 61220b5fe5af..a1104b2f92a9 100644 --- a/drivers/net/dsa/lantiq/mxl-gsw1xx.c +++ b/drivers/net/dsa/lantiq/mxl-gsw1xx.c @@ -688,7 +688,9 @@ static int gsw1xx_probe(struct mdio_device *mdiodev) { struct device *dev =3D &mdiodev->dev; struct gsw1xx_priv *priv; - u32 version; + u32 version, val; + u8 shellver; + u16 pnum; int ret; =20 priv =3D devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); @@ -736,6 +738,27 @@ static int gsw1xx_probe(struct mdio_device *mdiodev) if (IS_ERR(priv->shell)) return PTR_ERR(priv->shell); =20 + ret =3D regmap_read(priv->shell, GSW1XX_SHELL_MANU_ID, &val); + if (ret < 0) + return ret; + + /* validate chip ID */ + if (FIELD_GET(GSW1XX_SHELL_MANU_ID_FIX1, val) !=3D 1) + return -ENODEV; + + if (FIELD_GET(GSW1XX_SHELL_MANU_ID_MANID, val) !=3D + GSW1XX_SHELL_MANU_ID_MANID_VAL) + return -ENODEV; + + pnum =3D FIELD_GET(GSW1XX_SHELL_MANU_ID_PNUML, val); + + ret =3D regmap_read(priv->shell, GSW1XX_SHELL_PNUM_ID, &val); + if (ret < 0) + return ret; + + pnum |=3D FIELD_GET(GSW1XX_SHELL_PNUM_ID_PNUMM, val) << 4; + shellver =3D FIELD_GET(GSW1XX_SHELL_PNUM_ID_VER, val); + ret =3D gsw1xx_serdes_pcs_init(priv); if (ret < 0) return ret; @@ -756,6 +779,8 @@ static int gsw1xx_probe(struct mdio_device *mdiodev) if (ret) return ret; =20 + dev_info(dev, "standalone switch part number 0x%x v1.%u\n", pnum, shellve= r); + dev_set_drvdata(dev, &priv->gswip); =20 return 0; diff --git a/drivers/net/dsa/lantiq/mxl-gsw1xx.h b/drivers/net/dsa/lantiq/m= xl-gsw1xx.h index d1fded56e967..caa8f1008587 100644 --- a/drivers/net/dsa/lantiq/mxl-gsw1xx.h +++ b/drivers/net/dsa/lantiq/mxl-gsw1xx.h @@ -110,6 +110,15 @@ #define GSW1XX_SHELL_BASE 0xfa00 #define GSW1XX_SHELL_RST_REQ 0x01 #define GSW1XX_RST_REQ_SGMII_SHELL BIT(5) +#define GSW1XX_SHELL_MANU_ID 0x10 +#define GSW1XX_SHELL_MANU_ID_PNUML GENMASK(15, 12) +#define GSW1XX_SHELL_MANU_ID_MANID GENMASK(11, 1) +#define GSW1XX_SHELL_MANU_ID_MANID_VAL 0x389 +#define GSW1XX_SHELL_MANU_ID_FIX1 BIT(0) +#define GSW1XX_SHELL_PNUM_ID 0x11 +#define GSW1XX_SHELL_PNUM_ID_VER GENMASK(15, 12) +#define GSW1XX_SHELL_PNUM_ID_PNUMM GENMASK(11, 0) + /* RGMII PAD Slew Control Register */ #define GSW1XX_SHELL_RGMII_SLEW_CFG 0x78 #define RGMII_SLEW_CFG_DRV_TXC BIT(2) --=20 2.52.0