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[87.6.196.30]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-36bbcf0cc9csm13026496f8f.17.2024.08.06.06.03.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Aug 2024 06:03:28 -0700 (PDT) Message-ID: <66b21f20.5d0a0220.200175.4b9b@mx.google.com> X-Google-Original-Message-ID: Date: Tue, 6 Aug 2024 15:03:24 +0200 From: Christian Marangi To: Christoph Hellwig Cc: Ulf Hansson , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Joern Engel , Keith Busch , Jens Axboe , Sagi Grimberg , Wolfram Sang , Florian Fainelli , Thomas Bogendoerfer , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH v3 2/6] nvme: assign of_node to nvme device References: <20240806114118.17198-1-ansuelsmth@gmail.com> <20240806114118.17198-3-ansuelsmth@gmail.com> <20240806124312.GB10156@lst.de> Precedence: bulk X-Mailing-List: linux-mmc@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: <20240806124312.GB10156@lst.de> On Tue, Aug 06, 2024 at 02:43:12PM +0200, Christoph Hellwig wrote: > On Tue, Aug 06, 2024 at 01:41:12PM +0200, Christian Marangi wrote: > > Introduce support for a dedicated node for a nvme card. This will be a > > subnode of the nvme controller node that will have the "nvme-card" > > compatible. > > > > This follow a similar implementation done for mmc where the specific mmc > > card have a dedicated of_node. > > > > This can be used for scenario where block2mtd module is used to declare > > partition in DT and block2mtd is called on the root block of the nvme > > card, permitting the usage of fixed-partition parser or alternative > > ones. > > Err, hell no. Why would you wire up a purely PCIe device to OF? > PCIe is self-discovering. > Well on embedded pure PCIe card most of the time are not a thing... Unless it's an enterprise product, everything is integrated in the pcb and not detachable for cost saving measure or also if the thing use PCIe protocol but it tighlty coupled with the SoC. This implementation is already very common for all kind of pcie devices like wireless card, gpio expander that are integrated in the PCB and require property in DT like calibration data, quirks or GPIO pin definitions, i2c... In modern SoC we are seeing an influx of using cheap flash storage option instead of NAND or NOR as modern hw require more space and price increase is not that high... Almost any high tier device is switching to using emmc and even attached NVME and simulating MTD with them for easy usage. Please consider this well used scenario in emebedded where PCIe is just a comunication way and the concept of detachable doesn't exist at all and things can be described in DT as static. Also these storage are used for rootfs mount so userspace is not so viable. -- Ansuel 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 8D59AC3DA64 for ; Tue, 6 Aug 2024 13:03:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Subject:Cc:To:From: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=QQBbhxc7AYtOegD9SlcVee7+qIXVriWOq02eEajLwSE=; b=lM7yJINFDqVuF9 8fJYZdnS7Z8FZ6Ckqaq2je00wf3zbUAjGZt/zcI77kITukcS3E6s5LFHPDFLUZZckd9X7dTNAECUr 3rCLMqwpax+PS0vFHezievf2PZBbUiR1O7eeulXN6DuDU+zUUMi/IAOScYITX7/D1uRFgNDGEgoEg Mj4AIRdg7ahUckNBTVH7Gbh8xuihOQTGVjSuVH4EXsAp1FlbwelD1L55LzG0jeULBocSfTdb9APOQ ZnOlHwslGKkpHWhoECxLZnqihir+cqcD7AUR72VgPwU6cmpmh72p9xumGI7eQulMF/3VOKF5wjpAe +S/vq3yGB44+3UNFcMEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sbJqh-00000001cCC-3cPy; Tue, 06 Aug 2024 13:03:35 +0000 Received: from mail-wr1-x435.google.com ([2a00:1450:4864:20::435]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sbJqd-00000001cB5-2Wz8; Tue, 06 Aug 2024 13:03:33 +0000 Received: by mail-wr1-x435.google.com with SMTP id ffacd0b85a97d-369c609d0c7so465176f8f.3; Tue, 06 Aug 2024 06:03:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1722949409; x=1723554209; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:subject:cc :to:from:date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=NXqcooF+h0MdP2Fz1xLEPngVq2SpaVVQUfokhORQgX0=; b=cazLGFAK/N+FFADEWajk3V/6Y9cq9q5Ud21Zx2qKCPZVRVy1U2tKdEyPyRmBfsd3RE vM88W+RN4qQZbRHNv6GcutXqtmC68X2y2DGMxq0XDPeIEYkD2kqNEbtTGd01KM1vPa/d XpfDnQ1L9NK38wknpJME7rCzFZLs9SYOBF/Qr7BHue8WSovj/6FoP7dtY52dUYWs6dMz 7D4ip9WCozLsaB0q052uChMdvmmZAfFVoGfqADo0ohyFY9OStdvhiBzRUsOtF0rwJBEv HFNHeW7f70O4/OjFWZkMKQkar/FMgZYvKlBN95X5tIBWOlcXmHxqLNlwBnm2VptrjZ/v S8Zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722949409; x=1723554209; h=in-reply-to:content-disposition:mime-version:references:subject:cc :to:from:date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NXqcooF+h0MdP2Fz1xLEPngVq2SpaVVQUfokhORQgX0=; b=g3z2bQnXW30cfkjfphZgygg5EzO+NmQnkGLAY44pmzLO/Zqc6M+XDHJ7s7axsK6OrN m5fjjqv+K7aAsWrGRNzHPtHGpIQX1JHP1I+do70S3CYM+C1FFCe/M6prn19STuH+UpMZ sz97zNae+J9bEwIDL8qXVcelE9jbQ7gYODETMMO4fyD2CWLLM1E0p8QyhKRaOkTQ1eSK PpYZhe7oGDbMmgWoqOs9r0/NZqyurufoeVXBUWPUhFAs7mJXADQn0i1kFFI1CPzZHpS2 3ECJf3k65JAnhMUnrl5/MRyVaGFKbNw9905qqAdwz1ANPwEBHRWzRTEJnIKbYd0swRuU DLRg== X-Forwarded-Encrypted: i=1; AJvYcCVRypob6fzoGzXVbxRZQjp8ruwTwiOJCOyQmRmY2TBRibspd6npQN+idAhkpSCNhTF7DlvMcT+EA4p6oFfcqboOwAZ2pss2aihWQxdfcoPhPvqb8IJp4Vqi/GX0/WbLziPEeJDcxxnLfe33wyeo X-Gm-Message-State: AOJu0YxZJVksUFQ0VA/aytpe+lrpmFjHO4Q/13VSxxXqjXcUtpuAFGFc EDmPwSLa1a4o0d5kWndHFdaVUwHyK4k8Inb3kJutPse3gKsK/oWW X-Google-Smtp-Source: AGHT+IFE9bmHdwlb1KsEb5e3xHweTxoHAD/CnO0l3FUpup1/tPLMxcnaiVALbAIQ0dYjYRMgUd3Syg== X-Received: by 2002:adf:e7cf:0:b0:367:4d9d:56a1 with SMTP id ffacd0b85a97d-36bbc1a5f49mr10771026f8f.45.1722949409137; Tue, 06 Aug 2024 06:03:29 -0700 (PDT) Received: from Ansuel-XPS. 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[87.6.196.30]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-36bbcf0cc9csm13026496f8f.17.2024.08.06.06.03.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Aug 2024 06:03:28 -0700 (PDT) Message-ID: <66b21f20.5d0a0220.200175.4b9b@mx.google.com> X-Google-Original-Message-ID: Date: Tue, 6 Aug 2024 15:03:24 +0200 From: Christian Marangi To: Christoph Hellwig Cc: Ulf Hansson , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Joern Engel , Keith Busch , Jens Axboe , Sagi Grimberg , Wolfram Sang , Florian Fainelli , Thomas Bogendoerfer , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH v3 2/6] nvme: assign of_node to nvme device References: <20240806114118.17198-1-ansuelsmth@gmail.com> <20240806114118.17198-3-ansuelsmth@gmail.com> <20240806124312.GB10156@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240806124312.GB10156@lst.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240806_060331_684782_20CC2FE3 X-CRM114-Status: GOOD ( 21.06 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Tue, Aug 06, 2024 at 02:43:12PM +0200, Christoph Hellwig wrote: > On Tue, Aug 06, 2024 at 01:41:12PM +0200, Christian Marangi wrote: > > Introduce support for a dedicated node for a nvme card. This will be a > > subnode of the nvme controller node that will have the "nvme-card" > > compatible. > > > > This follow a similar implementation done for mmc where the specific mmc > > card have a dedicated of_node. > > > > This can be used for scenario where block2mtd module is used to declare > > partition in DT and block2mtd is called on the root block of the nvme > > card, permitting the usage of fixed-partition parser or alternative > > ones. > > Err, hell no. Why would you wire up a purely PCIe device to OF? > PCIe is self-discovering. > Well on embedded pure PCIe card most of the time are not a thing... Unless it's an enterprise product, everything is integrated in the pcb and not detachable for cost saving measure or also if the thing use PCIe protocol but it tighlty coupled with the SoC. This implementation is already very common for all kind of pcie devices like wireless card, gpio expander that are integrated in the PCB and require property in DT like calibration data, quirks or GPIO pin definitions, i2c... In modern SoC we are seeing an influx of using cheap flash storage option instead of NAND or NOR as modern hw require more space and price increase is not that high... Almost any high tier device is switching to using emmc and even attached NVME and simulating MTD with them for easy usage. Please consider this well used scenario in emebedded where PCIe is just a comunication way and the concept of detachable doesn't exist at all and things can be described in DT as static. Also these storage are used for rootfs mount so userspace is not so viable. -- Ansuel ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/