From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Francesco Dolcini <francesco@dolcini.it>
Cc: linux-mtd@lists.infradead.org,
Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Marek Vasut <marex@denx.de>,
Francesco Dolcini <francesco.dolcini@toradex.com>,
u-boot@lists.denx.de
Subject: Re: [PATCH v4] mtd: parsers: ofpart: add workaround for #size-cells 0
Date: Thu, 26 Jan 2023 10:01:02 +0100 [thread overview]
Message-ID: <Y9JBTgmA8WX03QzK@kroah.com> (raw)
In-Reply-To: <Y9GZ8c9VDXC582IA@francesco-nb.int.toradex.com>
On Wed, Jan 25, 2023 at 10:06:57PM +0100, Francesco Dolcini wrote:
> Hello Miquel, Greg and all
>
> On Tue, Jan 24, 2023 at 04:38:59PM +0100, Greg Kroah-Hartman wrote:
> > On Tue, Jan 24, 2023 at 11:44:44AM +0100, Francesco Dolcini wrote:
> > > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > >
> > > Add a mechanism to handle the case in which partitions are present as
> > > direct child of the nand controller node and #size-cells is set to <0>.
> > >
> > > This could happen if the nand-controller node in the DTS is supposed to
> > > have #size-cells set to 0, but for some historical reason/bug it was set
> > > to 1 in the past, and the firmware (e.g. U-Boot) is adding the partition
> > > as direct children of the nand-controller defaulting to #size-cells
> > > being to 1.
> > >
> > > This prevents a real boot failure on colibri-imx7 that happened during v6.1
> > > development cycles.
> > >
> > > Link: https://lore.kernel.org/all/Y4dgBTGNWpM6SQXI@francesco-nb.int.toradex.com/
> > > Link: https://lore.kernel.org/all/20221202071900.1143950-1-francesco@dolcini.it/
> > > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > ---
> > > I do not expect this patch to be backported to stable, however I would expect
> > > that we do not backport nand-controller dts cleanups neither.
> > >
> > > v4:
> > > fixed wrong English spelling in the comment
> > >
> > > v3:
> > > minor formatting change, removed not needed new-line and space.
> > >
> > > v2:
> > > fixup size-cells only when partitions are direct children of the nand-controller
> > > completely revised commit message, comments and warning print
> > > use pr_warn instead of pr_warn_once
> > > added Reviewed-by Greg
> > > removed cc:stable@ and fixes tag, since the problematic commit was reverted
> > > ---
> > > drivers/mtd/parsers/ofpart_core.c | 19 +++++++++++++++++++
> > > 1 file changed, 19 insertions(+)
> > >
> > > diff --git a/drivers/mtd/parsers/ofpart_core.c b/drivers/mtd/parsers/ofpart_core.c
> > > index 192190c42fc8..e7b8e9d0a910 100644
> > > --- a/drivers/mtd/parsers/ofpart_core.c
> > > +++ b/drivers/mtd/parsers/ofpart_core.c
> > > @@ -122,6 +122,25 @@ static int parse_fixed_partitions(struct mtd_info *master,
> > >
> > > a_cells = of_n_addr_cells(pp);
> > > s_cells = of_n_size_cells(pp);
> > > + if (!dedicated && s_cells == 0) {
> > > + /*
> > > + * This is a ugly workaround to not create
> > > + * regression on devices that are still creating
> > > + * partitions as direct children of the nand controller.
> > > + * This can happen in case the nand controller node has
> > > + * #size-cells equal to 0 and the firmware (e.g.
> > > + * U-Boot) just add the partitions there assuming
> > > + * 32-bit addressing.
> > > + *
> > > + * If you get this warning your firmware and/or DTS
> > > + * should be really fixed.
> > > + *
> > > + * This is working only for devices smaller than 4GiB.
> > > + */
> > > + pr_warn("%s: ofpart partition %pOF (%pOF) #size-cells is wrongly set to <0>, assuming <1> for parsing partitions.\n",
> > > + master->name, pp, mtd_node);
> >
> > This is a driver, always use dev_*() calls, not pr_*() calls so that we
> > know what is being referred to exactly.
>
> Is this reasonable here? Where can I get the struct device?
Walk back up the call chain, there has to be a device somewhere
controlling this, right?
> In general this file uses only pr_* debug API and messages are about OF
> nodes/properties, not about a device.
OF nodes and properties are part of a device's properties :)
thanks,
greg k-h
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next prev parent reply other threads:[~2023-01-26 9:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-24 10:44 [PATCH v4] mtd: parsers: ofpart: add workaround for #size-cells 0 Francesco Dolcini
2023-01-24 15:38 ` Greg Kroah-Hartman
2023-01-25 21:06 ` Francesco Dolcini
2023-01-26 8:42 ` Miquel Raynal
2023-01-26 9:01 ` Greg Kroah-Hartman [this message]
2023-01-26 9:12 ` Miquel Raynal
2023-02-02 11:33 ` Francesco Dolcini
2023-02-03 15:12 ` Miquel Raynal
2023-02-03 18:03 ` Francesco Dolcini
2023-02-03 18:16 ` Miquel Raynal
2023-02-03 18:37 ` Francesco Dolcini
2023-02-04 8:19 ` Greg Kroah-Hartman
2023-02-06 11:55 ` Miquel Raynal
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