Re: [PATCH v1 1/3] fdt: validate/fix cells count on mtdpart fixup

From: Francesco Dolcini <francesco@dolcini.it>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Marek Vasut <marex@denx.de>,
	Francesco Dolcini <francesco@dolcini.it>,
	Simon Glass <sjg@chromium.org>,
	u-boot@lists.denx.de,
	Marcel Ziswiler <marcel.ziswiler@toradex.com>,
	Francesco Dolcini <francesco.dolcini@toradex.com>,
	linux-mtd@lists.infradead.org
Subject: Re: [PATCH v1 1/3] fdt: validate/fix cells count on mtdpart fixup
Date: Tue, 24 Jan 2023 09:41:41 +0100	[thread overview]
Message-ID: <Y8+ZxTu05BEu5knS@francesco-nb.int.toradex.com> (raw)
In-Reply-To: <20230123105610.38034a11@xps-13>

Hello Miquel,

On Mon, Jan 23, 2023 at 10:56:10AM +0100, Miquel Raynal wrote:
> marex@denx.de wrote on Tue, 17 Jan 2023 01:59:54 +0100:
> 
> > On 1/16/23 19:00, Francesco Dolcini wrote:
> > > On Mon, Jan 16, 2023 at 06:54:44PM +0100, Marek Vasut wrote:  
> > >> On 1/16/23 15:20, Francesco Dolcini wrote:  
> > >>> On Sun, Jan 15, 2023 at 03:35:25PM +0100, Marek Vasut wrote:  
> > >>>> On 1/13/23 19:45, Francesco Dolcini wrote:  
> > >>>>> From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > >>>>>
> > >>>>> Fixup #size-cells value when updating the MTD partitions, this is
> > >>>>> required to prevent issues in case the MTD parent set #size-cells to
> > >>>>> zero.
> > >>>>> This could happen for example in the legacy case in which the partitions
> > >>>>> are created as direct child of the mtd node and that specific node has
> > >>>>> no children. Recent clean-up on Linux device tree files created a boot
> > >>>>> regression on colibri-imx7.
> > >>>>>
> > >>>>> This fixup has the limitation to assume 32-bit (#size-cells=1)
> > >>>>> addressing, therefore it will not work with device bigger than 4GiB.
> > >>>>>
> > >>>>> This change also enforce #address-cells to be the same as #size-cells,
> > >>>>> this was already silently enforced by fdt_node_set_part_info(), now this
> > >>>>> is checked explicitly and partition fixup will just fail in such case.
> > >>>>>
> > >>>>> In general board should not generally need nor use this functionality
> > >>>>> and should be just deprecated, passing mtdparts= in the kernel command
> > >>>>> line is the preferred way according to Linux MTD subsystem maintainer.
> 
> Just to be clear, I'm perfectly fine with the partitions being either
> on the cmdline or in the DT without preference (well, the cmdline only
> works with the simple generic parser, but whatever). What I really
> meant is that tweaking the DT from U-Boot should be rare and in no case
> the "right thing to add partitions".

Miquel, should I send a v2 to clarify the commit message or you do not
mind keeping it as it is?

Francesco

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