From: ron minnich <rminnich@gmail.com>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Richard Weinberger <richard@nod.at>,
linux-mtd@lists.infradead.org,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
Miquel Raynal <miquel.raynal@bootlin.com>
Subject: Re: [PATCH 1/1] mtd/intel-spi: Support cmdline-based partition
Date: Mon, 27 Apr 2020 13:31:35 -0700 [thread overview]
Message-ID: <CAP6exYJnKjzvC1g1qa8Odxg=HydD-CVbcz9yPi93Sbdg2K+bfw@mail.gmail.com> (raw)
In-Reply-To: <20200427114954.4fc0e8fc@collabora.com>
On Mon, Apr 27, 2020 at 2:50 AM Boris Brezillon
<boris.brezillon@collabora.com> wrote:
>
> On Mon, 27 Apr 2020 11:16:23 +0200
> Boris Brezillon <boris.brezillon@collabora.com> wrote:
>
> > Hi all,
> >
> > On Wed, 1 Apr 2020 09:41:48 +0200
> > Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> >
> > > Hi ron,
> > >
> > > ron minnich <rminnich@gmail.com> wrote on Mon, 30 Mar 2020 08:53:22
> > > -0700:
> > >
> > > > On Mon, Mar 30, 2020 at 12:27 AM Miquel Raynal
> > > > <miquel.raynal@bootlin.com> wrote:
> > > >
> > > > > Would it be hard to support an extra ':' after the MTD device name?
> > > > > This way would would allow anything inside the optional '(' ')' but
> > > > > would keep the trailing ':'.
> > > > >
> > > > > toTay:
> > > > > mtdparts=name:part1,part2
> > > > >
> > > > > So:
> > > > > mtdparts=(0000:00:1f.5):25165824(BIOS),-(squashfs)
> > > >
> > > >
> > > > I thought about that ':' too. It does add a bit more to the code, and
> > > > a bit more in the way of error cases. I always worry, when code is
> > > > going into flash,
> > > > about errors where something looks close to right but is wrong. (says
> > > > the person who just typed it instead of is a few times :-)
> > > >
> > > > What if we did this:
> > > > mtdparts=[0000:00:1f.5]25165824(BIOS),-(squashfs)
> > > >
> > > > Is the "]" 'enough different' that we do not need the ':'?
> > > >
> > > > I kind of like the [] better anyway as it makes the mtdid stand out a
> > > > bit more from the part names? But is it enough that we don't need the
> > > > ':'? Would you still prefer the () as opposed to the []?
> > >
> > > I like the [] as well, maybe more than () because at least it does not
> > > conflict with the partition names. But I really prefer keeping the : if
> > > the code is still readable.
> > >
> > > It is much easier to explain to people : "if you have a : in the name,
> > > enclose it with []".
> >
> > Sorry to chime in so late in the discussion, but I wonder if any of
> > that is necessary. Can't we just split the string per device (split
> > strings every time we see a ';'), and then find the last ':' in each of
> > those strings and consider everything before that last ':' to be the MTD
> > name. That should work even if the MTD name contains one or more ':'.
> >
> > Don't get me wrong, I'm perfectly fine with intel enclosing the PCI
> > address in [] to make it clearer, but I see that other drivers use ':'
> > in their MTD device names (the atmel raw NAND controller driver to name
> > one), so I think it'd be good to make the mtd part parsing robust to
> > this use case.
>
> I just gave it a try and the following patch should solve the problem
> (only compile-tested). As I said previously, it doesn't prevent you from
> enclosing the PCI address in [] if you think it's clearer, but I think
> the problem should be addressed in the cmdline parser anyway.
>
> --->8---
> From 08b30597dd73efd9c4c8d1906ab02a9540875419 Mon Sep 17 00:00:00 2001
> From: Boris Brezillon <boris.brezillon@collabora.com>
> Date: Mon, 27 Apr 2020 11:44:50 +0200
> Subject: [PATCH] mtd: parser: cmdline: Support MTD names containing one or
> more colons
>
> Looks like some drivers define MTD names with a colon in it, thus
> making mtdpart= parsing impossible. Let's fix the parser to gracefully
> handle that case: the last ':' in a partition definition sequence is
> considered instead of the first one.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
> drivers/mtd/parsers/cmdlinepart.c | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/parsers/cmdlinepart.c b/drivers/mtd/parsers/cmdlinepart.c
> index c86f2db8c882..0625b25620ca 100644
> --- a/drivers/mtd/parsers/cmdlinepart.c
> +++ b/drivers/mtd/parsers/cmdlinepart.c
> @@ -218,12 +218,29 @@ static int mtdpart_setup_real(char *s)
> struct cmdline_mtd_partition *this_mtd;
> struct mtd_partition *parts;
> int mtd_id_len, num_parts;
> - char *p, *mtd_id;
> + char *p, *mtd_id, *semicol;
> +
> + /*
> + * Replace the first ';' by a NULL char so strrchr can work
> + * properly.
> + */
> + semicol = strchr(s, ';');
> + if (semicol)
> + *semicol = '\0';
>
> mtd_id = s;
>
> - /* fetch <mtd-id> */
> - p = strchr(s, ':');
> + /*
> + * fetch <mtd-id>. We use strrchr to ignore all ':' that could
> + * be present in the MTD name, only the last one is interpreted
> + * as an <mtd-id>/<part-definition> separator.
> + */
> + p = strrchr(s, ':');
> +
> + /* Restore the ';' now. */
> + if (semicol)
> + *semicol = ';';
> +
> if (!p) {
> pr_err("no mtd-id\n");
> return -EINVAL;
Tested-by: rminnich@google.com
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next prev parent reply other threads:[~2020-04-27 20:32 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-23 19:58 [PATCH 1/1] mtd/intel-spi: Support cmdline-based partition ron minnich
2020-03-23 23:19 ` ron minnich
2020-03-25 17:34 ` ron minnich
2020-03-25 17:34 ` ron minnich
2020-03-27 15:48 ` ron minnich
2020-03-27 15:56 ` Mika Westerberg
2020-03-27 16:19 ` Miquel Raynal
2020-03-27 16:48 ` Mika Westerberg
2020-03-27 16:52 ` Miquel Raynal
2020-03-27 17:05 ` ron minnich
2020-03-27 17:16 ` Mika Westerberg
2020-03-27 17:39 ` ron minnich
2020-03-27 23:53 ` ron minnich
2020-03-30 6:08 ` Mika Westerberg
2020-03-30 7:27 ` Miquel Raynal
2020-03-30 15:53 ` ron minnich
2020-04-01 7:41 ` Miquel Raynal
2020-04-01 15:42 ` ron minnich
2020-04-01 19:49 ` ron minnich
2020-04-27 9:16 ` Boris Brezillon
2020-04-27 9:49 ` Boris Brezillon
2020-04-27 14:41 ` Miquel Raynal
2020-04-27 18:48 ` ron minnich
2020-04-27 18:50 ` ron minnich
2020-04-27 18:56 ` Miquel Raynal
2020-04-27 18:59 ` ron minnich
2020-04-27 19:21 ` Boris Brezillon
2020-04-27 19:31 ` ron minnich
2020-04-27 20:31 ` ron minnich [this message]
2020-04-27 21:20 ` Miquel Raynal
2020-03-27 16:53 ` ron minnich
2020-03-27 16:15 ` Miquel Raynal
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