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Date:   Thu, 20 Jul 2023 10:24:18 +0200
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Subject: Re: [RFC PATCH 3/6] block: add new genhd flag GENHD_FL_NO_NVMEM
To:     Daniel Golle <daniel@makrotopia.org>, Jens Axboe <axboe@kernel.dk>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Dave Chinner <dchinner@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        =?UTF-8?Q?Thomas_Wei=c3=9fschuh?= <linux@weissschuh.net>,
        Jan Kara <jack@suse.cz>, Damien Le Moal <dlemoal@kernel.org>,
        Ming Lei <ming.lei@redhat.com>, Min Li <min15.li@samsung.com>,
        Christian Loehle <CLoehle@hyperstone.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Jack Wang <jinpu.wang@ionos.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Yeqi Fu <asuk4.q@gmail.com>, Avri Altman <avri.altman@wdc.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Ye Bin <yebin10@huawei.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org
References: <cover.1689802933.git.daniel@makrotopia.org>
 <96510d925cb0ca1a3a132f8f8affd4bbdafd8fc9.1689802933.git.daniel@makrotopia.org>
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From:   Hannes Reinecke <hare@suse.de>
In-Reply-To: <96510d925cb0ca1a3a132f8f8affd4bbdafd8fc9.1689802933.git.daniel@makrotopia.org>
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On 7/20/23 00:03, Daniel Golle wrote:
> Add new flag to destinguish block devices which should not act as an
> NVMEM provider, such as for example an emulated block device on top of
> an MTD partition which already acts as an NVMEM provider itself.
> 
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> ---
>   include/linux/blkdev.h | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 2f5371b8482c0..e853d1815be15 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -80,11 +80,14 @@ struct partition_meta_info {
>    * ``GENHD_FL_NO_PART``: partition support is disabled.  The kernel will not
>    * scan for partitions from add_disk, and users can't add partitions manually.
>    *
> + * ``GENHD_FL_NO_NVMEM``: NVMEM emulation is disabled.  The kernel will not
> + * emulate an NVMEM device on top of this disk.
>    */
>   enum {
>   	GENHD_FL_REMOVABLE			= 1 << 0,
>   	GENHD_FL_HIDDEN				= 1 << 1,
>   	GENHD_FL_NO_PART			= 1 << 2,
> +	GENHD_FL_NO_NVMEM			= 1 << 3,
>   };
>   
>   enum {
Please reverse this flag. Most of the devices will not have an NVMEM 
partition, and we shouldn't require each and every driver to tag their 
devices.
So please use GENHD_FL_NVMEM and only set this flag on devices which 
really have an NVMEM partition.

Cheers,

Hannes