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 7E398CCFA13 for ; Thu, 6 Nov 2025 17:39:05 +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:In-Reply-To:Content-Type: MIME-Version:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=8khqmivdHqvLRaEjWc9ce8rzijxmIFPMF+BQyZmHFIg=; b=2K18WqQCF6g+zT UfjVpKcpkgGpRZ11wJXLMdvvaAQw44KVFTtero/ScRu+vxOHk7zc7zQHxeF2Q/Lb/iSYpi3nvxLqD cFljx2pfedC0xQShC6vrM9HKtsTCWeMvbM4kD35B6OyBPSXq1/tSSl2EczrTF7IX/Cag86N4t3joY vTmDyv/JHd60dmBpaVaFNwJU++ZcWrflLlwpDtK2bvFxlbfKygd/bR/NbU15CIfRmmCFwlXv4w5C3 oUoEgkq2ihB92deYOurf2iCRQvIkti1gdU20TcfR6WUTmeYLlyiHq0uEfgh3OaevA/oYyQIL/WTgK oD36DW1waGThKEci1JWg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vH3wn-0000000G2W8-2RQB; Thu, 06 Nov 2025 17:38:57 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vH3wl-0000000G2Vm-2A1J for linux-arm-kernel@lists.infradead.org; Thu, 06 Nov 2025 17:38:56 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id E12AE4018C; Thu, 6 Nov 2025 17:38:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90CEEC16AAE; Thu, 6 Nov 2025 17:38:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762450734; bh=KT4NxU4wzZtWzjzdNyOaIb2J5xsI7ldg+J7TbPIxc2s=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=RKZnoXF2yCM0esJy0nNdLPHb5DCoMw2//OUPJtCchG/Cd8esCy4W7xNGUF9NZtym8 HKyyWeEERf8/AN3v7TvGd/1muy/vbounHttD2Uc0onBdB+RQRKH1NUJ7jKOVP9HDn9 Udy27sHloM66hl2xBTgbs2TbZwUcZ/Q/PVqMKc69O8gNSxB2HEzAvcW+p+ri7OXkGT iDCXL8yE6hySjYsZIRNmC+WnR8BqEOjSREVal8M5UEwfGbaZgVEj0BLT7kUkRl9utH HiSeM77VN+qtG1pvUMbvDqQqHVhWrp8g3W6VLu1wLV7rMErYylWqQWpoGbikP1WMgS 8EdbtQuGnnPDg== Date: Thu, 6 Nov 2025 11:38:53 -0600 From: Bjorn Helgaas To: Vincent Guittot Cc: Manivannan Sadhasivam , chester62515@gmail.com, mbrugger@suse.com, ghennadi.procopciuc@oss.nxp.com, s32@nxp.com, bhelgaas@google.com, jingoohan1@gmail.com, lpieralisi@kernel.org, kwilczynski@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, Ionut.Vicovan@nxp.com, larisa.grigore@nxp.com, Ghennadi.Procopciuc@nxp.com, ciprianmarian.costea@nxp.com, bogdan.hamciuc@nxp.com, Frank.li@nxp.com, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, cassel@kernel.org, Senchuan Zhang Subject: Re: [PATCH 1/4 v3] dt-bindings: PCI: s32g: Add NXP PCIe controller Message-ID: <20251106173853.GA1959661@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251106_093855_576447_C09A010C X-CRM114-Status: GOOD ( 23.61 ) 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 [+cc Senchuan] On Thu, Nov 06, 2025 at 09:09:01AM +0100, Vincent Guittot wrote: > On Thu, 6 Nov 2025 at 08:12, Manivannan Sadhasivam wrote: > > On Wed, Oct 22, 2025 at 07:43:06PM +0200, Vincent Guittot wrote: > > > Describe the PCIe host controller available on the S32G platforms. > > > + phys = <&serdes0 PHY_TYPE_PCIE 0 0>; > > > > PHY is a Root Port specific resource, not Root Complex. So it > > should be moved to the Root Port node and the controller driver > > should parse the Root Port node and control PHY. Most of the > > existing platforms still specify PHY and other Root Port > > properties in controller node, but they are wrong. > > Yeah, we had similar discussion on v1 and as designware core code > doesn't support it, the goal was to follow other implementations > until designware core is able to parse root port nodes. I can add a > root port node for the phy and parse it in s32 probe function but > then If I need to restrict the number of lane to 1 instead of the > default 2 with num-lanes then I have to put it the controller node > otherwise designware core node will not get it. I think it's better to put the PHY info, including num-lanes, in Root Port DT nodes now even thought the DWC core doesn't explicitly support that yet because it's much easier to change the DWC core and the driver code than it is to change the DT structure. That will mean a little extra code in the s32g driver now, but we will be able to remove that eventually. If we leave the PHY in the DT controller node, we may eventually end up having to support two s32g DT structures: the single RP style with PHY in the controller, and a multiple RP style with PHY in the RP. We'll likely have both structures for many existing drivers, but I think it will be simpler if new drivers can avoid the old one. The eic7700 driver is an example of num-lanes support in the driver: https://lore.kernel.org/linux-pci/20251030083143.1341-1-zhangsenchuan@eswincomputing.com/ Bjorn