From nobody Sat Feb 7 04:36:08 2026 Received: from mail-wm1-f51.google.com (mail-wm1-f51.google.com [209.85.128.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BC88621 for ; Tue, 29 Oct 2024 12:43:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730205835; cv=none; b=O4lTQsBPQVFbE98NFkct8gv8jxFwRb+DQj/G5gwQuqzhGzs8lgYmLs4NXLAeGgRGOYVvqUi/RUtxou2R5sNdchEGHtbjUeo6IoQyM9eGKKHgnpgcG59Y1/edIOzg2T5puVt3s1Dm/7ZiK6s2UJv+V9RB/3YSl1oSX4Sbdz66gBs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730205835; c=relaxed/simple; bh=VAIjTC/o5nk8wiDyartM0yrRUBbC8NpqYhxF/SYj1uM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HzFu1bBL+24uq9cKaflSjtW7kb13B9Ac5+cFSnzTsLSZn7pej4ImqK+Fzrdnds5NiVhfp1gtgk3D0o1HJnEpHzSXnoe6NA0ReskMbFfVH13QjUaWOM5H8BFetjIq+cP4Irn1nBbAcNt2Zk7nGfrg3dk00X4wQ8AAMiy8JV0SR5g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sigma-star.at; spf=pass smtp.mailfrom=sigma-star.at; dkim=pass (2048-bit key) header.d=sigma-star.at header.i=@sigma-star.at header.b=uUUinjxN; arc=none smtp.client-ip=209.85.128.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sigma-star.at Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sigma-star.at Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sigma-star.at header.i=@sigma-star.at header.b="uUUinjxN" Received: by mail-wm1-f51.google.com with SMTP id 5b1f17b1804b1-431616c23b5so38533175e9.0 for ; Tue, 29 Oct 2024 05:43:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sigma-star.at; s=google; t=1730205831; x=1730810631; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=0ct56u9lAIlyQ0UHnyppJVp13Bh0/HOpwZWVs1n20D0=; b=uUUinjxNiRjqN6eLL755VeQ+bfk6QKwkPMdR2FRtmxy9rcOQKm0KDLixaFSSD+82FS tGsPY0js9owoQQz1pPTmCcwr2LYOXPytttdkzVq33HF6Diy70AiNS0pM9uAj5mzHb0Nv qNNML6nrL/W37rh8HaOHFeqnOSz+nCDbmzXxPBnXANOlMe5ACIPR+lB6Efe/N6rFHNJ6 qotU8tdJZY+KfZA/9T96JF0fHxyXAQ+/Npw5KVKOhhPmQWgBpYcDVRJHyDGdiwnwXWWt MgB0EukzRIjWucNHVTuSrWqwF9SL7Mc/ehQUw23K/O64Gvca/oyFCayfiyLAPuhjyZKV 9ZVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730205831; x=1730810631; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=0ct56u9lAIlyQ0UHnyppJVp13Bh0/HOpwZWVs1n20D0=; b=Q0R4tTMfpTAu+M1tRv18qtqi6qMmuRdFppNP7vYwj4UCBvsXHWJFbiABXBFB5pNTip OBRfNoA1ns6LNSnua0GjUNC6Qv0ZjqsHn2WwQlKPQZA+uQWNnOq7L+AEyQO0MEMKXoNy 4YDLBYkFAkcjVMZ+qsDecAYUKaXEblkVVLEJSFUJtWkqoy1tK1t0yq1xrZ+AywpAqfmc 6fnDx3n50iJwxFxhIuZ1i2v+8O+NNdxNi825jxXVFHC2YUxBtaLdt/bR8u5OvzMUYZc5 2Ek57bYuDoCEAdXYGwMzjvSU0Tfo/yyGs0GTNV0U9LG4+yMEXxTidf04xgG5etcWQtW1 aOFg== X-Forwarded-Encrypted: i=1; AJvYcCV6QR1qMYY0AyhO2eDE9tBgsJPNdJehOdgDFZaC4LKtyjsZwcq23I7wheK/oXTROEBtNbYzkn6yj3xWmHM=@vger.kernel.org X-Gm-Message-State: AOJu0YxQOn26FkHgiDDOV9kW9FTCmVt0zudekXeObVEW91J16iskdFpl SEIW1pdpz1nripGmZA9HTOuKb1b20c0F5iyk2ui/Kej8QjfQc4Ta8lfZlX1LIKs= X-Google-Smtp-Source: AGHT+IE9yfBCXXTlTJlwoojMc92ENtlt5lsQZG5GZ12S5D6IFW7eXJRgWuNHq1GKc7zlzhNBL9bCLw== X-Received: by 2002:a05:600c:3555:b0:42c:b166:913 with SMTP id 5b1f17b1804b1-431b5727f7fmr15525125e9.11.1730205830697; Tue, 29 Oct 2024 05:43:50 -0700 (PDT) Received: from localtoast.corp.sigma-star.at ([82.150.214.1]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-38058b1c645sm12433940f8f.17.2024.10.29.05.43.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Oct 2024 05:43:50 -0700 (PDT) From: David Oberhollenzer To: netdev@vger.kernel.org, andrew@lunn.ch Cc: Julian.FRIEDRICH@frequentis.com, f.fainelli@gmail.com, olteanv@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-kernel@vger.kernel.org, upstream+netdev@sigma-star.at, David Oberhollenzer Subject: [PATCH] net: dsa: mv88e6xxx: properly shutdown PPU re-enable timer on destroy Date: Tue, 29 Oct 2024 13:42:45 +0100 Message-ID: <20241029124332.51008-1-david.oberhollenzer@sigma-star.at> X-Mailer: git-send-email 2.46.2 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 Content-Type: text/plain; charset="utf-8" The mv88e6xxx has an internal PPU that polls PHY state. If we want to access the internal PHYs, we need to disable it. Because enable/disable of the PPU is a slow operation, a 10ms timer is used to re-enable it, canceled with every access, so bulk operations effectively only disable it once and re-enable it some 10ms after the last access. If a PHY is accessed and then the mv88e6xxx module is removed before the 10ms are up, the PPU re-enable ends up accessing a dangling pointer. This is easily triggered by deferred probing during boot-up. MDIO bus and PHY registration may succeed, but switch registration fails later on, because the CPU port depends on a very slow device. In this case, probe() fails, but the MDIO subsystem may already have accessed bus or the PHYs, arming timer. This is fixed as follows: - If probe fails after mv88e6xxx_phy_init(), make sure we also call mv88e6xxx_phy_destroy() before returning - In mv88e6xxx_phy_destroy(), grab the ppu_mutex to make sure the work function either has already exited, or (should it run) cannot do anything, fails to grab the mutex and returns. - In addition to destroying the timer, also destroy the work item, in case the timer has already fired. - Do all of this synchronously, to make sure timer & work item are destroyed and none of the callbacks are running. Signed-off-by: David Oberhollenzer --- FWIW, this is a forward port of a patch I'm using on v6.6. Thanks, David --- drivers/net/dsa/mv88e6xxx/chip.c | 8 +++++--- drivers/net/dsa/mv88e6xxx/phy.c | 3 +++ 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/c= hip.c index 284270a4ade1..c2af69bed660 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -7264,13 +7264,13 @@ static int mv88e6xxx_probe(struct mdio_device *mdio= dev) err =3D mv88e6xxx_switch_reset(chip); mv88e6xxx_reg_unlock(chip); if (err) - goto out; + goto out_phy; =20 if (np) { chip->irq =3D of_irq_get(np, 0); if (chip->irq =3D=3D -EPROBE_DEFER) { err =3D chip->irq; - goto out; + goto out_phy; } } =20 @@ -7289,7 +7289,7 @@ static int mv88e6xxx_probe(struct mdio_device *mdiode= v) mv88e6xxx_reg_unlock(chip); =20 if (err) - goto out; + goto out_phy; =20 if (chip->info->g2_irqs > 0) { err =3D mv88e6xxx_g2_irq_setup(chip); @@ -7323,6 +7323,8 @@ static int mv88e6xxx_probe(struct mdio_device *mdiode= v) mv88e6xxx_g1_irq_free(chip); else mv88e6xxx_irq_poll_free(chip); +out_phy: + mv88e6xxx_phy_destroy(chip); out: if (pdata) dev_put(pdata->netdev); diff --git a/drivers/net/dsa/mv88e6xxx/phy.c b/drivers/net/dsa/mv88e6xxx/ph= y.c index 8bb88b3d900d..ee9e5d7e5277 100644 --- a/drivers/net/dsa/mv88e6xxx/phy.c +++ b/drivers/net/dsa/mv88e6xxx/phy.c @@ -229,7 +229,10 @@ static void mv88e6xxx_phy_ppu_state_init(struct mv88e6= xxx_chip *chip) =20 static void mv88e6xxx_phy_ppu_state_destroy(struct mv88e6xxx_chip *chip) { + mutex_lock(&chip->ppu_mutex); del_timer_sync(&chip->ppu_timer); + cancel_work_sync(&chip->ppu_work); + mutex_unlock(&chip->ppu_mutex); } =20 int mv88e6185_phy_ppu_read(struct mv88e6xxx_chip *chip, struct mii_bus *bu= s, --=20 2.46.2