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Date:   Fri, 21 Jul 2023 13:10:09 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Ming Lei <ming.lei@redhat.com>
Cc:     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>,
        Thomas =?iso-8859-1?Q?Wei=DFschuh?= <linux@weissschuh.net>,
        Jan Kara <jack@suse.cz>, Damien Le Moal <dlemoal@kernel.org>,
        Min Li <min15.li@samsung.com>,
        Christian Loehle <CLoehle@hyperstone.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Hannes Reinecke <hare@suse.de>,
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        Florian Fainelli <f.fainelli@gmail.com>,
        Yeqi Fu <asuk4.q@gmail.com>, Avri Altman <avri.altman@wdc.com>,
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        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org
Subject: Re: [RFC PATCH 0/6] nvmem: add block device NVMEM provider
Message-ID: <2023072118-flyable-aspect-060f@gregkh>
References: <cover.1689802933.git.daniel@makrotopia.org>
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On Fri, Jul 21, 2023 at 04:32:49PM +0800, Ming Lei wrote:
> On Wed, Jul 19, 2023 at 11:01:14PM +0100, Daniel Golle wrote:
> > On embedded devices using an eMMC it is common that one or more (hw/sw)
> > partitions on the eMMC are used to store MAC addresses and Wi-Fi
> > calibration EEPROM data.
> > 
> > Implement an NVMEM provider backed by block devices as typically the
> > NVMEM framework is used to have kernel drivers read and use binary data
> > from EEPROMs, efuses, flash memory (MTD), ...
> > 
> > In order to be able to reference hardware partitions on an eMMC, add code
> > to bind each hardware partition to a specific firmware subnode.
> > 
> > This series is meant to open the discussion on how exactly the device tree
> > schema for block devices and partitions may look like, and even if using
> > the block layer to back the NVMEM device is at all the way to go -- to me
> > it seemed to be a good solution because it will be reuable e.g. for NVMe.
> 
> Just wondering why you don't use request_firmware() in drivers which consume
> the data, then the logic can be moved out of kernel, and you needn't to deal
> with device tree & block device.
> 
> Or Android doesn't support udev and initrd?

It does support initrd, but not really udev last I looked.

But it does allow request_firmware() to be called at boot time, so yes,
finding out why that isn't used here would be good.

thanks,

greg k-h