From mboxrd@z Thu Jan 1 00:00:00 1970 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 607483F1AC9; Thu, 9 Jul 2026 09:44:52 +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=1783590293; cv=none; b=iGnQLpzr7t5dTfenVJB6mAGqN/YemAtI/btCh1/SaSpnYFRrU8rhYoYjXK+tymBAZtdBVvCGqcDwbSofJ/ghFDBPLNe6H9PwkUo0vBk1Uh/N4+j5RehNr/06J6rElC5D+dNV3mcpQCvFksTfWv9B4f1EZl0OvLG5GlAQEZDVvNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783590293; c=relaxed/simple; bh=7Ou5+3G75tDZu799wGoMAdBW6+Fh+b5nNnd6FitkyyM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XWAsNTNtOU0n6RZ0d7Yiuty13CBUFfE0oKJP4VoeWybMCnvn03sCEkaMsqe3u6t2+UzhR9JDY4/HO4oH76KSq/49wsDY3SoGBYshfkFTBBcB6nmZXC5dEVZIvbHLLGrCjHNfBgDw+NHpv8v3lA3lZ7SuCZiPj8F+lnSX6OCU5JU= 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 1whlJJ-000000005VW-1BkQ; Thu, 09 Jul 2026 09:44:49 +0000 Date: Thu, 9 Jul 2026 11:44:41 +0200 From: Daniel Golle To: Andrew Lunn Cc: Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH RFC net-next 2/3] net: dsa: mxl862xx: add SMDIO clause-22 register access Message-ID: References: <96c362d3-59d2-43c4-b2aa-c12dfeb6fcca@lunn.ch> <98505e14-d684-4225-9415-f4d872113998@lunn.ch> Precedence: bulk X-Mailing-List: netdev@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: <98505e14-d684-4225-9415-f4d872113998@lunn.ch> On Thu, Jul 09, 2026 at 01:15:34AM +0200, Andrew Lunn wrote: > On Wed, Jul 08, 2026 at 09:45:48PM +0200, Daniel Golle wrote: > > On Wed, Jul 08, 2026 at 07:22:49PM +0200, Andrew Lunn wrote: > > > On Tue, Jul 07, 2026 at 04:16:07PM +0200, Daniel Golle wrote: > > > > Add mxl862xx_smdio_read() and mxl862xx_smdio_write() for clause-22 > > > > SMDIO register access. MCUboot rescue mode only exposes clause-22 > > > > registers; the existing clause-45 MMD interface is unavailable during > > > > firmware transfer. The MDIO bus lock is held per-transaction (not > > > > across polls) so that SB PDI polling during flash erase does not > > > > starve other MDIO users. > > > > > > What other MDIO users are there? It sounds like once the switch is in > > > rescue mode, switch management is dead. So how can there be users? > > > > The MDIO bus lock refers to the host bus which is used to connect > > the switch management interface. The same bus can also be used to > > connect other unrelated PHYs (eg. to provide a WAN or management > > interface independent of the switch). > > Thanks for the explanation. Maybe 'does not starve other non-switch > MDIO users'? > > I've not got to the rest of the patch yet, but i wondered if phylib > might still be trying to poll the switches PHYs. The driver takes down the CPU ports and thereby implicitely also puts all user-ports into admin-down state, effectively disabling PHY polling until the switch comes back and reprobe has happened.