From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (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 A061F30112A for ; Thu, 17 Jul 2025 16:27:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752769678; cv=none; b=h50V/O33feAfacnFHZQterC8RqJmG5SUQABTcCU/FAfvyAgEn7O38lTisXJjmAASo5lHv6IIENPsO116K+mtMBxrxLvjGm6e/WfG3ApvMNWWtpw8Eaq7GBRSYPR8mzaTekD3z6Uf69Wd3LHK/iiQKcTz0nApn6A/41IZ+GtGgXQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752769678; c=relaxed/simple; bh=YLu4Qo0NgwDqCYSE9LkUP789zJ9Z1MNQWKn0CtVFQhM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=l1Ez809sa6DyrWrmQ8SD+jNQSpDjZZXu8LIqRqZdwpt88sgmv1LjEpfbtdxHT/OgAE5DFBJksAzVFSkScki6eK8Bm//01z0KHTCk9h71dof5Mn8DezY6G3mUh6jP0WBz1/5CPPfbAmS4XZpQF7QdhpGscYWrzd5jvSERumZCXsg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=eJaW5FYN; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="eJaW5FYN" Message-ID: <03e04d98-e5eb-41c0-8407-23cccd578dbe@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1752769673; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4Ay4UsrwBiPcaslZNYrakqAaTaS1CuBXla7xAvqK4iw=; b=eJaW5FYN3JIqaJZB1WK5+nmumKzxiIdylG3v2/byRwszJdN7xY/ErtD/wKGWIDxY/r0CyE eA0uTx59AjxDvKL5jzF7aI4+g82sbb19mGdMvZ9tY80nyztEB9+ROft0/sFIfvW0x7RkAV TDgELQ4sup+IAwpp036PgvB8G8CbbSo= Date: Thu, 17 Jul 2025 12:27:44 -0400 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net v2 1/4] auxiliary: Support hexadecimal ids To: Greg Kroah-Hartman Cc: Radhey Shyam Pandey , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, Dave Ertman , Saravana Kannan , Leon Romanovsky , linux-kernel@vger.kernel.org, Michal Simek , linux-arm-kernel@lists.infradead.org, Ira Weiny References: <20250716000110.2267189-1-sean.anderson@linux.dev> <20250716000110.2267189-2-sean.anderson@linux.dev> <2025071637-doubling-subject-25de@gregkh> <719ff2ee-67e3-4df1-9cec-2d9587c681be@linux.dev> <2025071747-icing-issuing-b62a@gregkh> <5d8205e1-b384-446b-822a-b5737ea7bd6c@linux.dev> <2025071736-viscous-entertain-ff6c@gregkh> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Sean Anderson In-Reply-To: <2025071736-viscous-entertain-ff6c@gregkh> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 7/17/25 12:21, Greg Kroah-Hartman wrote: > On Thu, Jul 17, 2025 at 12:04:15PM -0400, Sean Anderson wrote: >> On 7/17/25 11:59, Greg Kroah-Hartman wrote: >> > On Thu, Jul 17, 2025 at 11:49:37AM -0400, Sean Anderson wrote: >> >> On 7/16/25 01:09, Greg Kroah-Hartman wrote: >> >> > On Tue, Jul 15, 2025 at 08:01:07PM -0400, Sean Anderson wrote: >> >> >> Support creating auxiliary devices with the id included as part of the >> >> >> name. This allows for hexadecimal ids, which may be more appropriate for >> >> >> auxiliary devices created as children of memory-mapped devices. If an >> >> >> auxiliary device's id is set to AUXILIARY_DEVID_NONE, the name must >> >> >> be of the form "name.id". >> >> >> >> >> >> With this patch, dmesg logs from an auxiliary device might look something >> >> >> like >> >> >> >> >> >> [ 4.781268] xilinx_axienet 80200000.ethernet: autodetected 64-bit DMA range >> >> >> [ 21.889563] xilinx_emac.mac xilinx_emac.mac.80200000 net4: renamed from eth0 >> >> >> [ 32.296965] xilinx_emac.mac xilinx_emac.mac.80200000 net4: PHY [axienet-80200000:05] driver [RTL8211F Gigabit Ethernet] (irq=70) >> >> >> [ 32.313456] xilinx_emac.mac xilinx_emac.mac.80200000 net4: configuring for inband/sgmii link mode >> >> >> [ 65.095419] xilinx_emac.mac xilinx_emac.mac.80200000 net4: Link is Up - 1Gbps/Full - flow control rx/tx >> >> >> >> >> >> this is especially useful when compared to what might happen if there is >> >> >> an error before userspace has the chance to assign a name to the netdev: >> >> >> >> >> >> [ 4.947215] xilinx_emac.mac xilinx_emac.mac.1 (unnamed net_device) (uninitialized): incorrect link mode for in-band status >> >> >> >> >> >> Signed-off-by: Sean Anderson >> >> >> --- >> >> >> >> >> >> Changes in v2: >> >> >> - Add example log output to commit message >> >> > >> >> > I rejected v1, why is this being sent again? >> >> >> >> You asked for explanation, I provided it. I specifically pointed out why >> >> I wanted to do things this way. But I got no response. So here in v2. >> > >> > Again, I said, "do not do that, this is not how ids work in the driver >> > model", and you tried to show lots of reasons why you wanted to do it >> > this way despite me saying so. >> > >> > So again, no, sorry, this isn't ok. Don't attempt to encode information >> > in a device id like you are trying to do here, that's not what a device >> > id is for at all. I need to go dig up my old patch that made all device >> > ids random numbers just to see what foolish assumptions busses and >> > userspace tools are making.... >> >> But it *is* how ids work in platform devices. > > No one should ever use platform devices/bus as an excuse to do anything, > it's "wrong" in so many ways, but needs to be because of special > reasons. No other bus should work like that, sorry. > >> And because my auxiliary >> devices are created by a platform device, it is guaranteed that the >> platform device id is unique and that it will also be unique for >> auxiliary devices. So there is no assumption here about the uniqueness >> of any given id. > > Then perhaps use the faux device api instead? There's *another* pseudo bus? OK the reason why is that faux was added four months ago and there is nothing under Documentation for it. So I had no idea it existed. I will have a look, but perhaps you should write up some documentation about why someone might want to use a "faux" bus over the auxiliary bus or MFD. --Sean