From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A9A641DA62E; Thu, 17 Jul 2025 16:33:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752769988; cv=none; b=TtfxhfX02pRdyRhEA/B+yUTnjSwsHw4SY5FCWzZvNEaz/tK1Jy06Ljm+IlhAppduWPHN4+CEMJ+Cl2HcjzPsYhd3Ej/zx/PVVfNMT05AsYd6OjHdhTxJFyEbt44Xn8Dl4K11zwXGFd7ObjdvoxMx03Ks5Agu2vFLZUPHFSYuppQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752769988; c=relaxed/simple; bh=eQMhoaVeh9uL/LQThbKAyyzQTwwiWXQJw5qztLmSJSk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eAVJkhJiPG2prbPaWEfwmFVwGpyfd659gJqraJ1590ObUHd0JjwV/gOPK08XVlJ7y/4mgSN2jj+yRvXNs7CJ/rD3kiDSbzOD7mtULwIfwNOEirKtCSVtfp2f8NK8JpyVw6a5oykqhCx5y56gzzQnGNE/qF/oacJXdnhmBVe3hZ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=j+tSECtT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="j+tSECtT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9222FC4CEE3; Thu, 17 Jul 2025 16:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1752769988; bh=eQMhoaVeh9uL/LQThbKAyyzQTwwiWXQJw5qztLmSJSk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j+tSECtTPZKlPChTcyEBIOo36vO4qPc2DiJVglGxnRk+nMGfCKdY746T73G0/E5Zc COlnqXsuowmFMOkB/Z1ReHIzifEwHWWUgxeRqHk78klRgaYkkOK5SxEezL6eZd9S5s 45tN0uR7TCmpHUjwIsAijMprDxVCRfXt8liZsHbY= Date: Thu, 17 Jul 2025 18:33:05 +0200 From: Greg Kroah-Hartman To: Sean Anderson 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 Subject: Re: [PATCH net v2 1/4] auxiliary: Support hexadecimal ids Message-ID: <2025071726-ramp-friend-a3e5@gregkh> 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> <03e04d98-e5eb-41c0-8407-23cccd578dbe@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: <03e04d98-e5eb-41c0-8407-23cccd578dbe@linux.dev> On Thu, Jul 17, 2025 at 12:27:44PM -0400, Sean Anderson wrote: > 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. "faux" is for when platform devices were being abused because someone just wanted a device in the device tree, and did not use any of the platform device resources. Yes, more documentation is always a good idea, someday... thanks, greg k-h