From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) (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 499C42505C4; Wed, 19 Mar 2025 08:21:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742372485; cv=none; b=sGA20aaBxyCE9Jrq6rLfXgeDvXtUsguxirEsbNAbvrhQstjl1I21EOwWS5ahvXMIJ2hSZ5GgNVIZqGa3OM1lFDmMfDP1fLOXW/aa6SQjIDgCRqSTSAQYxjVWnRdgOnzLg8gYL7HmfnRoRMVQCS5WSB4n5vmWuVj4mtL4mM71fBo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742372485; c=relaxed/simple; bh=SAE9X4EEjY2ZvGnbvYn6CgWKevjhg+JZh0D4LXYQWSc=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=EnoRiJGQEdUyrLy48R2i+DiVzDHUWRWIB3tOh2jw5ffZqB6m/OBA/f9F2tiTi9VNFnUf6lJpv4ZjG2gdgf/vqoDf44osw9B/uaStMAljx2EMBnUH5CkAre0EPvTDw9wV4ST2DWr+fKHOjplg5F63hGCC5ptiHJ85k0kvK7bQvQU= ARC-Authentication-Results:i=1; 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bh=w+li3VJN1jkxERZLWTNPHaOMZTpe2H6m5wVIrNKLoMY=; b=jq/0SFTbB0DqTIk6jgz9+JIMiRX2v42uordG7LZrw21p1NT989w+Ad2jwL7bOVHGxAiKUE lZpDSgfXar49+B+qcp3zOgyDv2ND9ccISl9nhB5mdUGemRgPmiwUDCNgkIktUFDAlsj/oj xhdCy4KnUw6kImhvObGjpv/sUjYFLl3ZrESr828HFSC9/HKD6jGvJm+saGv7kNPUFFMXCc 681QqfiQ78h+el8TYnR9gAr+EvT/4RoWoGkyF1bfrAV68zweAXXEoKEzh58CTVp/W3K1B+ lPKvblwiQXKdE5l/vkJk0cmdgCfDUAp9KIocRKNlG+V1todppirSuOjiGpYawg== From: Miquel Raynal To: "Mahapatra, Amit Kumar" Cc: "richard@nod.at" , "vigneshr@ti.com" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "linux-mtd@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "git (AMD-Xilinx)" , "amitrkcian2002@gmail.com" , Bernhard Frauendienst Subject: Re: [PATCH v12 3/3] mtd: Add driver for concatenating devices In-Reply-To: (Amit Kumar Mahapatra's message of "Wed, 19 Mar 2025 06:17:50 +0000") References: <20250205133730.273985-1-amit.kumar-mahapatra@amd.com> <20250205133730.273985-4-amit.kumar-mahapatra@amd.com> <8734fa8hed.fsf@bootlin.com> User-Agent: mu4e 1.12.7; emacs 29.4 Date: Wed, 19 Mar 2025 09:21:19 +0100 Message-ID: <87h63p5t34.fsf@bootlin.com> 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=utf-8 Content-Transfer-Encoding: quoted-printable X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddugeegkeegucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufgjfhgffffkgggtgfesthhqredttderjeenucfhrhhomhepofhiqhhuvghlucftrgihnhgrlhcuoehmihhquhgvlhdrrhgrhihnrghlsegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeejgeeftdefledvieegvdejlefgleegjefhgfeuleevgfdtjeehudffhedvheegueenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecukfhppeeltddrkeelrdduieefrdduvdejnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepledtrdekledrudeifedruddvjedphhgvlhhopehlohgtrghlhhhoshhtpdhmrghilhhfrhhomhepmhhiqhhuvghlrdhrrgihnhgrlhessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepuddvpdhrtghpthhtoheprghmihhtrdhkuhhmrghrqdhmrghhrghprghtrhgrsegrmhgurdgtohhmpdhrtghpthhtoheprhhitghhrghrugesnhhougdrrghtpdhrtghpthhtohepvhhighhnvghshhhrsehtihdrtghomhdprhgtphhtthhopehrohgshheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepkhhriihkodgutheskhgvrhhnvghlrdhorhhgp dhrtghpthhtoheptghonhhorhdoughtsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhmthgusehlihhsthhsrdhinhhfrhgruggvrggurdhorhhgpdhrtghpthhtohepuggvvhhitggvthhrvggvsehvghgvrhdrkhgvrhhnvghlrdhorhhg X-GND-Sasl: miquel.raynal@bootlin.com On 19/03/2025 at 06:17:50 GMT, "Mahapatra, Amit Kumar" wrote: > [AMD Official Use Only - AMD Internal Distribution Only] > > Hello Miquel, > >> -----Original Message----- >> From: Miquel Raynal >> Sent: Tuesday, March 18, 2025 9:23 PM >> To: Mahapatra, Amit Kumar >> Cc: richard@nod.at; vigneshr@ti.com; robh@kernel.org; krzk+dt@kernel.org; >> conor+dt@kernel.org; linux-mtd@lists.infradead.org; devicetree@vger.kern= el.org; >> linux-kernel@vger.kernel.org; git (AMD-Xilinx) ; >> amitrkcian2002@gmail.com; Bernhard Frauendienst >> Subject: Re: [PATCH v12 3/3] mtd: Add driver for concatenating devices >> >> On 05/02/2025 at 19:07:30 +0530, Amit Kumar Mahapatra > mahapatra@amd.com> wrote: >> >> > Introducing CONFIG_VIRT_CONCAT to separate the legacy flow from the >> > new >> >> CONFIG_MTD_VIRT_CONCAT >> >> > approach, where individual partitions within a concatenated partition >> > are not registered, as they are likely not needed by the user. >> >> I am not a big fan of this choice. We had issues with hiding things to t= he user in the >> first place. Could we find a way to expose both the original mtd devices= as well as >> the virtually concatenated partitions? > > Sure, I think that can be done, but I took this approach to hide the > original devices because Boris mentioned in [1] that we are creating > the original partitions even though the user probably doesn't need > them. I believe he is right, as I can't think of any use case where > the user would require the individual devices instead of the > concatenated device. > > [1] https://lore.kernel.org/linux-mtd/20191209113506.41341ed4@collabora.c= om/ He was suggesting not to create the intermediate partitions, and I agree it is not super relevant, but the flash devices themselves are relevant. In this example: concatenate =3D <&part2>, <&part3>; flash@0 { part1 { } part2 { } }; flash@0 { part3 { } part4 { } }; part1, part2, part3, part4 are partitions, at least part1 and part4 should appear like mtd devices. Boris was suggesting to not expose part2 and part3 individually when concatenating them, I'm fine with that. What I am saying, is that flash@0 and flash@1 shall be represented by two mtd devices and not hidden/skipped. Thanks, Miqu=C3=A8l