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Message-ID: <192acb8f-47b8-426c-bcc9-ef214a797f26@acm.org>
Date: Fri, 22 Mar 2024 12:22:32 -0700
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Subject: Re: [PATCH 3/8] block: add new genhd flag GENHD_FL_NVMEM
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To: Daniel Golle <daniel@makrotopia.org>
Cc: Rob Herring <robh@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 Conor Dooley <conor+dt@kernel.org>, Ulf Hansson <ulf.hansson@linaro.org>,
 Jens Axboe <axboe@kernel.dk>, Dave Chinner <dchinner@redhat.com>,
 Jan Kara <jack@suse.cz>, =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?=
 <linux@weissschuh.net>, Damien Le Moal <dlemoal@kernel.org>,
 Li Lingfeng <lilingfeng3@huawei.com>, Christian Brauner
 <brauner@kernel.org>, Christian Heusel <christian@heusel.eu>,
 Min Li <min15.li@samsung.com>, Adrian Hunter <adrian.hunter@intel.com>,
 Avri Altman <avri.altman@wdc.com>, Hannes Reinecke <hare@suse.de>,
 Christian Loehle <CLoehle@hyperstone.com>, Bean Huo <beanhuo@micron.com>,
 Yeqi Fu <asuk4.q@gmail.com>, Victor Shih <victor.shih@genesyslogic.com.tw>,
 Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
 Dominique Martinet <dominique.martinet@atmark-techno.com>,
 "Ricardo B. Marliere" <ricardo@marliere.net>, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org,
 linux-block@vger.kernel.org
References: <cover.1711048433.git.daniel@makrotopia.org>
 <89abd9ab93783da0e8934ebc03d66559f78f6060.1711048433.git.daniel@makrotopia.org>
 <7027ccdc-878a-420e-a7ea-5156e1d67b8a@acm.org>
 <Zf3I6DDqqyd924Ks@makrotopia.org>
From: Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <Zf3I6DDqqyd924Ks@makrotopia.org>
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On 3/22/24 11:07, Daniel Golle wrote:
> On Fri, Mar 22, 2024 at 10:49:48AM -0700, Bart Van Assche wrote:
>> On 3/21/24 12:33, Daniel Golle wrote:
>>>    enum {
>>>    	GENHD_FL_REMOVABLE			= 1 << 0,
>>>    	GENHD_FL_HIDDEN				= 1 << 1,
>>>    	GENHD_FL_NO_PART			= 1 << 2,
>>> +	GENHD_FL_NVMEM				= 1 << 3,
>>>    };
>>
>> What would break if this flag wouldn't exist?
> 
> As both, MTD and UBI already act as NVMEM providers themselves, once
> the user creates a ubiblock device or got CONFIG_MTD_BLOCK=y set in their
> kernel configuration, we would run into problems because both, the block
> layer as well as MTD or UBI would try to be an NVMEM provider for the same
> device tree node.

Why would both MTD and UBI try to be an NVMEM provider for the same
device tree node? Why can't this patch series be implemented such that
a partition UUID occurs in the device tree and such that other code
scans for that partition UUID?

Thanks,

Bart.