From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 306742EEE74; Sun, 7 Jun 2026 17:28:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780853304; cv=none; b=I3zyMV0OfTVMR9Dts+XJ+5P7Nf7rfTeSAoUxO0QDzLo43Ew1wB247or1Ig58/fX3hBp268aZIbsAP3YF0KkexArD9vmNkqcV3XkbCJ2/hkrPKKL7wT9G7g8kS86tcxpM83cs73t6rQqLcAiFmBfOT0kesBEvwbarOJ/SYLQbUsg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780853304; c=relaxed/simple; bh=g6Qssiyd/0gNBdIF+YVWj7h6uA4J1vqU8FZUZN3RMP0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=H7osp+L6mYy3veA4FAP9iyG5ASgmLow39LUEIWgnVXFTdm6bZo2m/f1g/XUHhEs4sGFwFDZSfS19KdulwTs8KJ9PTP63AbDXFFAsEDo4FEsafA/gYLgQZSGpAjkdWlzr3GaPHU0q6Io37OQl/+KaH030XZjsB2EO1MZyqyjERW4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=fJoVabPR; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="fJoVabPR" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=vkRXkBHTm1p59dLWdZH+b6kuiXEG97WGreWW32kZBcI=; b=fJoVabPRm7sSrD8SYBAPv9XVuB LT8iLJLArRNeO/aE9RYUAGc2UybhReA9LeCxwjmdNXi7ZZ2uG+pKUCZklygP0URF0PSHp8/fxButY By5OHnJhEYiimEZgKMRhn04GSJXudvFgLOUK+4Ah64tvzeWqNi1ZgfbX0AN1nryfapdw=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1wWHI2-006UPP-OB; Sun, 07 Jun 2026 19:28:02 +0200 Date: Sun, 7 Jun 2026 19:28:02 +0200 From: Andrew Lunn To: Mieczyslaw Nalewaj Cc: Luiz Angelo Daros de Luca , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Linus Walleij , Alvin =?utf-8?Q?=C5=A0ipraga?= , Yury Norov , Rasmus Villemoes , Russell King , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [net-next PATCH v13 2/9] net: dsa: realtek: rtl8365mb: reject unsupported topologies Message-ID: <9f8d3ee8-4249-4cb2-925d-53b2996239db@lunn.ch> References: <20260606-realtek_forward-v13-0-b9e409687cbe@gmail.com> <20260606-realtek_forward-v13-2-b9e409687cbe@gmail.com> <617aa489-4f0c-4fe0-8cf3-55c98f4d4d9e@yahoo.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <617aa489-4f0c-4fe0-8cf3-55c98f4d4d9e@yahoo.com> On Sun, Jun 07, 2026 at 02:55:07PM +0200, Mieczyslaw Nalewaj wrote: > On 6/6/2026 10:29 AM, Luiz Angelo Daros de Luca wrote: > > Explicitly enforce the presence of a CPU port (-EINVAL) and reject DSA > > cascade links (-EOPNOTSUPP) during setup to prevent silent failures. > > > > These topologies were already non-functional. Without a CPU port, the > > driver does not activate CPU tagging. Additionally, the switch hardware > > was not designed to be cascaded, and DSA links never worked because > > CPU tagging is not enabled for them. > > > > Reviewed-by: Mieczyslaw Nalewaj > > Reviewed-by: Linus Walleij > > Signed-off-by: Luiz Angelo Daros de Luca > > --- > [...] > >drivers/net/dsa/realtek/rtl8365mb.c:rtl8365mb_get_stats64() { > > ... > > mb = priv->chip_data; > > p = &mb->ports[port]; > > spin_lock(&p->stats_lock); > > memcpy(s, &p->stats, sizeof(*s)); > > spin_unlock(&p->stats_lock); > >} > > Sashiko reports a potential deadlock around stats_lock, however I couldn't find a call chain reaching rtl8365mb_get_stats64() from softirq context. Can anyone point to such a path? Enable CONFIG_PROVE_LOCKING and use the device, get the statistics etc. If you hit the two paths with a potential deadlock you will get a report. Andrew