From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) (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 1F8AB19E97C; Mon, 12 May 2025 10:01:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.196 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747044115; cv=none; b=QDDk/89ibKsKwnKfaM9bdz7P8tqeDOuSzZEOKVDPpHO8S7mM07iMdR4Q1V3fJfUTGY+IBSGXEId99WDQAhHxmLySg+cqwW6uWalR8kO9F4hdOYdD7A/Z1foR520c1Z454IWuAtkTrHarBs21sJmTnCAIUMJL688DstJM95WTIyk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747044115; c=relaxed/simple; bh=Lvpug9FEpAMKnwLUgy1E94q5V5F3Hp/cYHFhJlR7iIo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=bZcs7jv7GBmvsa1zPyNPhZe4eI3iNGxjbFVDYAMQ9OcKN7INALDdUBNCbBB44amvBXoIWyYNyavBdCCvRjrPsX0/Mw6h8lgm9eTp0K9Qf7+XJeNwdkbyZPofPYwbZdE4eM277uQf7bsA5+w7YVzGuRicU46qtN6ycQXJ9pnCU8w= ARC-Authentication-Results:i=1; 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bh=23/KllP1Vs2xVFOmNRG8GlctBkDoHOk55ezgK8BXOUY=; b=S2t2lVKCHSX+Pvb0Cy6ezCRITtuaBvgqqxJxHdHge7MRpTtFm6Fc74aZuRFzNCExVU7uej JsvO2Q/6gxMMV5CeOML88qNGwLBKAfjcy5x81fhr3FFIZ752NFvgXQi17jtQQl1rIVJPgR Fdi13vV00/fYO6CU7anq4ynM8HI6vIxq6XyTee6haGxsIp5kXSBRQNqD+yl7Yp/V3jggC2 d3NusWAq0bgwsW8TtJs1PFjC4pOYD+374mBBoaU1Jm8jhUOTVDz9TKeMAzsZP/JEQZXVtK iOVk0II5ppF0936fAYEsrm29BU/vN/JDQD9nU8mFFJKKyrYe20oBzqlEvMLxLQ== 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, 30 Apr 2025 14:18:34 +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: Mon, 12 May 2025 12:01:50 +0200 Message-ID: <87o6vyjgfl.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: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdeftddtleejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufgjfhgffffkgggtgfesthhqredttderjeenucfhrhhomhepofhiqhhuvghlucftrgihnhgrlhcuoehmihhquhgvlhdrrhgrhihnrghlsegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeffgefhjedtfeeigeduudekudejkedtiefhleelueeiueevheekvdeludehiedvfeenucfkphepledtrdekledrudeifedruddvjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeltddrkeelrdduieefrdduvdejpdhhvghloheplhhotggrlhhhohhsthdpmhgrihhlfhhrohhmpehmihhquhgvlhdrrhgrhihnrghlsegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopeduvddprhgtphhtthhopegrmhhithdrkhhumhgrrhdqmhgrhhgrphgrthhrrgesrghmugdrtghomhdprhgtphhtthhopehrihgthhgrrhgusehnohgurdgrthdprhgtphhtthhopehvihhgnhgvshhhrhesthhirdgtohhmpdhrtghpthhtoheprhhosghhsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehkrhiikhdoughtsehkvghrnhgvlhdrohhrghdprhgtphhtthhopegtohhnohhrodgutheskhgvr hhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqmhhtugeslhhishhtshdrihhnfhhrrgguvggrugdrohhrghdprhgtphhtthhopeguvghvihgtvghtrhgvvgesvhhgvghrrdhkvghrnhgvlhdrohhrgh X-GND-Sasl: miquel.raynal@bootlin.com >> > + mtd->dev.parent =3D concat->subdev[0]->dev.parent; >> > + mtd->dev =3D concat->subdev[0]->dev; >> > + >> > + /* Register the platform device */ >> > + ret =3D mtd_device_register(mtd, NULL, 0); >> > + if (ret) >> > + goto destroy_concat; >> > + } >> > + >> > + return 0; >> > + >> > +destroy_concat: >> > + mtd_concat_destroy(mtd); >> > + >> > + return ret; >> > +} >> > + >> > +late_initcall(mtd_virt_concat_create_join); >> >> The current implementation does not support probe deferrals, I believe i= t should be >> handled. > > I see that the parse_mtd_partitions() API can return -EPROBE_DEFER during > MTD device registration, but this behavior is specific to the > parse_qcomsmem_part parser. None of the other parsers appear to support > probe deferral. As discussed in RFC [1], the virtual concat feature is > purely a fixed-partition capability, and based on my understanding, the > fixed-partition parser does not support probe deferral. > Please let me know if you can think of any other probe deferral scenarios > that might impact the virtual concat driver. That's true, but I kind of dislike the late_initcall, I fear it might break in creative ways. Thanks, Miqu=C3=A8l