From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793864819; b=H/SP79nlbOdmRxFGlAFYCUMaxoGSCOa4NauhWonNTvamya0drzu5mD9yB2PIGdLS2j88 RBjsWWf6q41Uy0tFmVxhaX694dnH2L2jtI1+UlzBCSLExa+iKnHfx6gb2OS5wjng0ixod HEzany/6iWdI2hwIqYFCGiMOQGbYDcvosh2hvK+ajPS2PvsPfti6lkreytlirHna50Eik jzI0rhr/dgYwd4RsZhRhpHUcLYXDx6DudfBagN6RLPgJAPrmkJYKiUDncA1EBGjfFhqPK mnuQ0tTSaCVBEU0MojTAlMc/A5fdWVQbjXtD/fhEPQmFqO7dxiIXkXzpCPLCnYlEMQw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793864819; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=PU50rkTM7P9N/lvPiRkmpsgKA2mgcVLrq2zbVJoPex4=; b=x1oHF6+fp0z9DdNiwl1h3C6V5N66vEEFKMpXgb3O1MzjpyBtgSgyILQnynb+CtF278aa GAaw7XDEBCHw2CNxBM8GDvtdUs0vwll2+h77XGOZ6pKyb5PoiA0CT3x9JdHloYW5l09jq bekRXL5uGjU+HVxBoP1x7fAX3e6ELsOEird5Vak2IQfVcGSgBt6eIDsq70hJ6xHy+McP8 7XjhU/9j3bmdM5ApII2xTwkGoRFk4rnsS6Ft5bQBjEm2JOAWBdvhUGi2m4RuLU+a1jTQN tMfz2cGXs5SRlXH2V1bdOoVkkdTVfe3krIggQLjqv1xSdnJMdWZ5JfTV1YLyadrbPBA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="fh/7Sh08"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 28D31606A328; Thu, 5 Nov 2026 07:46:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fh/7Sh08 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B3261F000C1; Thu, 5 Nov 2026 07:46:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793864818; bh=PU50rkTM7P9N/lvPiRkmpsgKA2mgcVLrq2zbVJoPex4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=fh/7Sh08z2YJ1Yqdw8RZUNKty9ZCz/hgiv/J0VYHAxJHoE+0XM8dtRZgD6YYPFJdV q4Mqw/AE0dWFofaBAcYKlFYf/RefqB4PF5MOyXqfDIkxJJtQZJzqKipcxJIbpfDP8H 9kg7IP7Y9MUuNPI/eWfDjQEE/EXtqtLY07nUyESiRtGORUROfsD4QDuGZoqaYei/KX mW/L2dc1IUUmVPDfzjs5nN+q80/7sHhDJJszahEvOn5T9myCeL9szljDSUqM9fVdNO RlIkwbhI4hK0UPtI3h7vhgmDvPEKbz/edinZukySfsuRvqnxNVZisUuSp+E/K43RHm I/g41vmHdx3Dg== Message-ID: Date: Thu, 5 Nov 2026 08:46:51 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] dt-bindings: PCI: Add linux,pci-domain-reuse property To: Cui Chao , Will Deacon , Krzysztof Kozlowski , Conor Dooley , Bjorn Helgaas Cc: Lorenzo Pieralisi , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Manivannan Sadhasivam , Rob Herring , Wang Yinfeng , linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20261102095150.2370959-1-cuichao1753@phytium.com.cn> <20261102095150.2370959-2-cuichao1753@phytium.com.cn> <8112d8ca-2234-490c-a4a2-c3b01adfbc88@kernel.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGPBBMBCgA5AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJp2mE8AAoJEBuTQ307QWKbeaIP /ihHTkTW4KsN/DQ945JJbyu5tI0J80Wue7QyyLPglyKfhgb5cLLNPpOC8cCIJsc7+W3i2P38 s2c1cOH6CYGE7E9ur3Vfme8NW2S2I/Z8VC7bZnzyS23wT17LrsdS/qCpx4o8U+pt/xdXDKph EGRYrIEmMpUWvyYzyYKGIe25FtaayIIKpq8eZYyFcp2f/sG5IkOW5uZzHPMPdcm87jU7fyuQ rAU2vx9r+ulUfQ/q9Z2roC/ode3l7t2pN7BCBCsUDp6JCrUyZrtT1e7EbA0ZRP3aOBNk2P2E DQOgJGjGdO5Yx2Y9LFtltu6JbsBJHi1syGRX3AtQYOMc4Y1WGoeZJmMlvKj2ZqqXNkcWi2DS IQEWB0uW6CqFsBBIMGDa+6OzdaVO/uAVXWDWml02Men3CILdI1MbVjoh8ECqYUY7OQ+JJvNN vnliuq5WM3Ghd3jg/LZZrxXjdIginRHFQCjIJYLKpLZWm1/iDFedcfzqRNYmTtqscdCNHW41 oT3Z7BmO9xwdjuwBS6nmS6JJwkbf5Ot2QR4pB/DRU7ZwjT1qHe+9r9gF32wXVQatHNGK/VVu sfwOnkdxCWkp/qb2gdQRmZh+SedStWshigH6sNfuHBloF/q+hjMRc8b2m326OZdrbSHwY1Sz vti8Hn7n8NjdHO9LKB7BIdjkA9DA5WsqOuVCzsFNBFVDXDQBEADNkrQYSREUL4D3Gws46JEo Z9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLueMNsWLJBv BaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6eiOMheesVS 5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wAGldWsRxb f3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA6z6lBZn0 WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9YegxWKvX XHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt91pFzBSO IpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gUBLHFTg2h YnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/JoFzZ4B0 p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu4vXVFBYI GmpyNPYzRm0QPwARAQABwsF2BBgBCgAgAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtBYpsFAmna YUkACgkQG5NDfTtBYptX+BAApg32CkxwNucNEi8WfWA8oKkW0y8YDuY6ORMo9FWNGiT/OTy0 vyJrLocrpn86zwfjVp+eCrssPYh8eqJfnWqmYv6ACQtHPYzPZQ3mSo8H97Z01oUxITzCxpXm ZkLgPIqtDPcC2E3dPM/fVxcyowM8XsaMA9wcsaUYrta8toOq2b9tKcjleKMfMrm0gQ9u7wUc QbLkwj6TCLOwucb07GXzLTNF9PZmaDUpKAZjMjmrW+le+SFvQbhamx0rxLWPR0NWntXpbCn+ +ACch03p/JyTBVktxFsFyCt7pTPE1kEaeuXBTe/a2D9iQvRxRW19LvuO2e59/u1wYUiH/orz wbIC2S4dBsPAPihL3ztOU1yE86GPyQtSE0kU+/7snnLt4QGi6PChf3t5gnNjAzjUUovO8rgI c+5yN5heq5loYHgK6OQ9OlHzsPHO9e9MOQcKlFycs1pyijFGzDwdNUm/SchK8iWT2QApTx4A K9bCVaboTA2T77QYkRcRJYSsO1alGX0ome/hMLD1daXlkrNUp1HWa3K4iytLRXjCSIorWiGs n+q3krnpXu3TFkA8qtOFZMdnIiFuiq1yLT8hptsV5xh1TA2nsVvSYiaCr3q4s4BKjS/KrLDb qoxzw8ISjdUp4pA85vb6YLCmb39NgidD+7PmAr65lBNveIFynTgsja1rRQ4= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 05/11/2026 08:35, Cui Chao wrote: > > On 11/4/2026 3:23 PM, Krzysztof Kozlowski wrote: >> On 03/11/2026 03:57, Cui Chao wrote: >>> On 11/2/2026 6:00 PM, Krzysztof Kozlowski wrote: >>>> On 02/11/2026 10:51, Cui Chao wrote: >>>>> Add a new optional boolean property 'linux,pci-domain-reuse' for PCI >>>>> host bridges. >>>>> >>>>> By default, the 'linux,pci-domain' property must be unique across all >>>>> host bridges. This property allows a host bridge to explicitly opt-out >>>>> of this uniqueness check, permitting multiple host bridges to reuse the >>>>> same software domain number. >>>> Why isn't this deducible from the compatibles? >>> Hi Krzysztof, >>> >>> Thanks. >>> >>> The compatible cannot express this. "pci-host-ecam-generic" only >> You have vendor specific compatibles, no? > > > I used a tool to assist me earlier. I will now discuss directly. > The driver used by our hardware is not a vendor specific driver but > the generic "pci-host-generic" driver, so previously the compatible > in our DTS was only "pci-host-ecam-generic", with no vendor specific > compatibles. Why aren't you using vendor specific compatible? > >>> describes how configuration space is accessed; it does not describe >>> whether two host bridge instances may share one Linux PCI domain. >>> >>> The same compatible is used on systems where every host bridge must >>> have a unique domain and on this system where two RCs intentionally >>> share a domain with disjoint bus ranges and resource windows. >>> Comparing the compatible strings of the nodes therefore cannot >>> distinguish our case. >> OK, so let's look at your DTS - where is it posted for upstream? > > > The DTS has not been uploaded upstream. Below is our DTS (with So do we need the property in upstream in such case? > irrelevant information such as interrupts and IOMMU omitted). Both > nodes use only "pci-host-ecam-generic", and their resources do not > overlap, but the domain is the same. > >  pcie0: pcie@80000000 { >         compatible = "pci-host-ecam-generic"; >         device_type = "pci"; >         #address-cells = <0x3>; >         #size-cells = <0x2>; >         #interrupt-cells = <0x1>; >         reg = <0x0 0x80000000 0x0 0x8000000>; >         linux,pci-domain = <0>; >         bus-range = <0x0 0x7f>; >         ranges = <0x1000000 0x0 0x100000 0x0 0x10000000 0x0 0x100000 >                           0x2000000 0x0 0x20000000 0x0 0x20000000 0x0 > 0x10000000 >                           0x43000000 0x200 0x0 0x200 0x0 0x100 0x0>; >  }; > >  pcie1: pcie@88000000 { >         compatible = "pci-host-ecam-generic"; >         device_type = "pci"; >         #address-cells = <0x3>; >         #size-cells = <0x2>; >         #interrupt-cells = <0x1>; >         reg = <0x0 0x88000000 0x0 0x8000000>; >         linux,pci-domain = <0>; >         bus-range = <0x80 0xff>; >         ranges = <0x1000000 0x0 0x200000 0x0 0x10100000 0x0 0x100000 >                           0x2000000 0x0 0x30000000 0x0 0x30000000 0x0 > 0x10000000 >                           0x43000000 0x300 0x0 0x300 0x0 0x100 0x0>; >  }; > Anyway, I clearly see no usage of linux,pci-domain-reuse in above code, so I think this closes the case. Best regards, Krzysztof