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 4F2703594B; Mon, 23 Jun 2025 22:45:31 +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=1750718732; cv=none; b=Lxcq6Ehb0C62FvmjbLQdovxEKI3FAewPgjuNO70/smVY5K9MwIVkZRkBWDgeYQ+PAFsTiESgfu7m91Msy2vkEZr337zWyrOBaapFbsDNogHltbCKoTuZbUYC4Rlk2pXeBauGuGrjWNhdMr9+FMb5HnYx2ouaD1SUWeOkYYNBxEc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750718732; c=relaxed/simple; bh=CeO8AY4lnLWCMgU1gN94LRHZAB8UqehzLbM0fBlC9DU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IpHQqqMdAy5MD40E6cY8C0z4cjb0SsMplX5KySS5VsnR3SV9OPDcwpCAvIv9MVkNgIw0M0Jb8PQUFCz7tIm7nyMhf6pcKM9uDLficJ7Woq/3vj29N25IoHey5D5jl+JeNmwUIE1UlN7vdVv6SkRqhwLYIlGfU+aG6MRkhuR+LKA= 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=zS4OurQO; 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="zS4OurQO" 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=CHdSNTwyhEj3ZOnn8e0uBB6QJpASsij9hXSlRqn95gA=; b=zS4OurQOgKjixDkTZUxxvRu1MV cdvpkvkICmkHHCwoGqsknSGMpLlkE+f2CHsH1GUTo+zHMFyt7HiJiDwUxjvk4ckGiGAhhp5uNT6yG F16tQKiX5GaqxW2XIWe8IRjvrgPKywJIstwjT9jHUCiiul80dG5BXcawhVwVujbdZbSc=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1uTpuc-00Gjnq-Lj; Tue, 24 Jun 2025 00:45:14 +0200 Date: Tue, 24 Jun 2025 00:45:14 +0200 From: Andrew Lunn To: Sean Anderson Cc: Radhey Shyam Pandey , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, Greg Kroah-Hartman , Michal Simek , Saravana Kannan , Leon Romanovsky , Dave Ertman , linux-kernel@vger.kernel.org, Ira Weiny , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH net 4/4] net: axienet: Split into MAC and MDIO drivers Message-ID: <3e2acebe-a9db-494b-bca8-2e1bbc3c1eaf@lunn.ch> References: <20250619200537.260017-1-sean.anderson@linux.dev> <20250619200537.260017-5-sean.anderson@linux.dev> <16ebbe27-8256-4bbf-ad0a-96d25a3110b2@lunn.ch> <0854ddee-1b53-472c-a4fe-0a345f65da65@linux.dev> 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: On Mon, Jun 23, 2025 at 02:48:53PM -0400, Sean Anderson wrote: > On 6/23/25 14:27, Andrew Lunn wrote: > > On Mon, Jun 23, 2025 at 11:16:08AM -0400, Sean Anderson wrote: > >> On 6/21/25 03:33, Andrew Lunn wrote: > >> > On Thu, Jun 19, 2025 at 04:05:37PM -0400, Sean Anderson wrote: > >> >> Returning EPROBE_DEFER after probing a bus may result in an infinite > >> >> probe loop if the EPROBE_DEFER error is never resolved. > >> > > >> > That sounds like a core problem. I also thought there was a time > >> > limit, how long the system will repeat probes for drivers which defer. > >> > > >> > This seems like the wrong fix to me. > >> > >> I agree. My first attempt to fix this did so by ignoring deferred probes > >> from child devices, which would prevent "recursive" loops like this one > >> [1]. But I was informed that failing with EPROBE_DEFER after creating a > >> bus was not allowed at all, hence this patch. > > > > O.K. So why not change the order so that you know you have all the > > needed dependencies before registering the MDIO bus? > > > > Quoting your previous email: > > > >> Returning EPROBE_DEFER after probing a bus may result in an infinite > >> probe loop if the EPROBE_DEFER error is never resolved. For example, > >> if the PCS is located on another MDIO bus and that MDIO bus is > >> missing its driver then we will always return EPROBE_DEFER. > > > > Why not get a reference on the PCS device before registering the MDIO > > bus? > > Because the PCS may be on the MDIO bus. This is probably the most-common > case. So you are saying the PCS is physically there, but the driver is missing because of configuration errors? Then it sounds like a kconfig issue? Or are you saying the driver has been built but then removed from /lib/modules/ Andrew