From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6397BC83F1A for ; Thu, 17 Jul 2025 17:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+EluqO2moZ07z54L0ghbT5HaZt1N6sU75p1MHiMf6X4=; b=2WoXl+n8oAvyThVlBVJXgWVBXb +nNrM8N55E3Oq/jb7oAsaah6ongwy5h3Uajnm6kE4sElbgrOogzLo6+q7ipc3iZYG6g7Adj8JLcPj 4a4zOmX8O4Me6i1Dse1PxXKr+NrYbjct2kPinGmv7XqA+KCkebl2j/L1aprE4hCszXXCowSLprPvt io5qybLEfyAhZTcUIvuOb4SXd+Iozrh5/1EqVK2dfeFtEe+CV80WSlJXNy/omtQX948Q3YgOc2Xtn RwhZ07Or31Wax9cX2+GqDOwtbmBjpLj/WNCmysiVv9iZ7vXK/jUXgjVwfeNgVzfbonNiwqcYBk4aP v/w//bDQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ucSC2-0000000AlZm-1Xdc; Thu, 17 Jul 2025 17:14:50 +0000 Received: from out-180.mta0.migadu.com ([2001:41d0:1004:224b::b4]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1ucS9Y-0000000AlBD-2Sra for linux-arm-kernel@lists.infradead.org; Thu, 17 Jul 2025 17:12:18 +0000 Message-ID: <5ee4bac4-957b-481a-8608-15886da458c2@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1752772333; 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=+EluqO2moZ07z54L0ghbT5HaZt1N6sU75p1MHiMf6X4=; b=ckjsxq98tfEm25Th4zH5CRqje3rC68aGTOC/Bz9djpqcTCgTf7FWRD/UptBN0Z8iycl2fz Urr+zWCtba04bzEP+CB2lSUU7vfWCQcHB1Q4/Eo5D2a1CgSN2dm79DE3nsMuIvl/8Oxqg7 GOayi3n/u+4ztkqeCj69hLCLZkwdNdg= Date: Thu, 17 Jul 2025 13:12:08 -0400 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> <03e04d98-e5eb-41c0-8407-23cccd578dbe@linux.dev> <2025071726-ramp-friend-a3e5@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: <2025071726-ramp-friend-a3e5@gregkh> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250717_101217_272132_7C876470 X-CRM114-Status: GOOD ( 31.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 7/17/25 12:33, Greg Kroah-Hartman wrote: > 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. OK, well that's not this. These are real devices and there may be more than one per system. Actually, that's the primary problem I wanted to address with this patch: you can't create more than one device with devm_auxiliary_device_create because they will have the same id (0). Anyway, if you really think ids should be random or whatever, why not just ida_alloc one in axiliary_device_init and ignore whatever's provided? I'd say around half the auxiliary drivers just use 0 (or some other constant), which is just as deterministic as using the device address. Another third use ida_alloc (or xa_alloc) so all that could be removed. And the remainder just use an address of some kind (which ends up be formatted as decimal). --Sean