Re: [PATCH v7 01/12] mtd: core: always create master device

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Alexander Usyskin <alexander.usyskin@intel.com>
Cc: "Richard Weinberger" <richard@nod.at>,
	"Vignesh Raghavendra" <vigneshr@ti.com>,
	"Lucas De Marchi" <lucas.demarchi@intel.com>,
	"Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
	"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"David Airlie" <airlied@gmail.com>,
	"Simona Vetter" <simona@ffwll.ch>,
	"Jani Nikula" <jani.nikula@linux.intel.com>,
	"Joonas Lahtinen" <joonas.lahtinen@linux.intel.com>,
	"Tvrtko Ursulin" <tursulin@ursulin.net>,
	"Karthik Poosa" <karthik.poosa@intel.com>,
	"Reuven Abliyev" <reuven.abliyev@intel.com>,
	"Oren Weil" <oren.jer.weil@intel.com>,
	linux-mtd@lists.infradead.org, dri-devel@lists.freedesktop.org,
	intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 01/12] mtd: core: always create master device
Date: Tue, 01 Apr 2025 17:00:43 +0200	[thread overview]
Message-ID: <87ecycrko4.fsf@bootlin.com> (raw)
In-Reply-To: <20250326152623.3897204-2-alexander.usyskin@intel.com> (Alexander Usyskin's message of "Wed, 26 Mar 2025 17:26:12 +0200")

Hello Alexander,

On 26/03/2025 at 17:26:12 +02, Alexander Usyskin <alexander.usyskin@intel.com> wrote:

> Create master device without partition when
> CONFIG_MTD_PARTITIONED_MASTER flag is unset.
>
> This streamlines device tree and allows to anchor
> runtime power management on master device in all cases.
>
> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>

I successfully tested it, this patch will be applied at -rc1 to the
mtd/next tree.

I was wondering, do you think it would be possible to keep the creation
of mtd_master and make it a symbolic link to mtdx when
MTD_PARTITIONED_MASTER=y or when there is no partition? In short, always
having mtd_masterx, because I fear at some point we'll have problems
otherwise :-)

Right now we have:

- Without partition:
mtd0 (mtd0ro mtdblock0)
- With partition and MTD_PARTITIONED_MASTER=n
mtd0 (mtd0ro mtdblock0)
mtd_master0
- With partition and MTD_PARTITIONED_MASTER=y
mtd0 (mtd0ro mtdblock0) [this is the master]
mtd1 (mtd1ro mtdblock1)

I am suggesting:
- Without partition:
mtd0 (mtd0ro mtdblock0)
mtd_master0 -> link to mtd0
- With partition and MTD_PARTITIONED_MASTER=n
mtd0 (mtd0ro mtdblock0)
mtd_master0
- With partition and MTD_PARTITIONED_MASTER=y
mtd0 (mtd0ro mtdblock0) [this is the master]
mtd1 (mtd1ro mtdblock1)
mtd_master0 -> link to mtd0

What do you think? Or maybe even always mtd_master in the first place.

Richard, your point of view on this?

Thanks,
Miquèl