From: marex@denx•de (Marek Vasut)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 04/11] mtd: ofpart: do not fail probe when no partitions exist
Date: Fri, 5 Jun 2015 16:13:09 +0200 [thread overview]
Message-ID: <201506051613.09187.marex@denx.de> (raw)
In-Reply-To: <CAOMqctQTxVZspcocDsNP6GzsRw5-0zPqkNScS8PzNvkFjBWatQ@mail.gmail.com>
On Thursday, June 04, 2015 at 05:40:58 PM, Michal Suchanek wrote:
> On 4 June 2015 at 17:28, Marek Vasut <marex@denx•de> wrote:
> > On Thursday, June 04, 2015 at 06:54:00 AM, Michal Suchanek wrote:
> >> On 4 June 2015 at 00:58, Marek Vasut <marex@denx•de> wrote:
> >> > On Wednesday, June 03, 2015 at 11:26:40 PM, Michal Suchanek wrote:
> >> >> On Exynos it is necessary to set SPI controller parameters that apply
> >> >> to a SPI slave in a DT subnode of the slave device. The ofpart code
> >> >> returns an error when there are subnodes of the SPI flash but no
> >> >> partitions are found. Change this condition to a warning so that
> >> >> flash without partitions can be accessed on Exynos.
> >> >
> >> > I have to admit the rationale for this patch is not very clear to me,
> >> > sorry. Can you please explain this a bit more ?
> >>
> >> This is how the DT entry for SPI slave looks with s3c64xx:
> >> flash: m25p80 at 0 {
> >>
> >> #address-cells = <1>;
> >> #size-cells = <1>;
> >> compatible = "jedec,spi-nor";
> >> reg = <0>;
> >> spi-max-frequency = <40000000>;
> >> linux,max_tx_len = <65536>;
> >
> > SIDENOTE: I thought this was actually added by your patch #8 in this
> > series. The underscores in the name of the property are not really
> > consistent with the rest of the names.
> >
> >> m25p,fast-read;
> >> controller-data {
> >>
> >> samsung,spi-feedback-delay = <0>;
> >>
> >> };
> >>
> >> };
> >>
> >> this is example of flash partitions:
> >> flash at 0 {
> >>
> >> #address-cells = <1>;
> >> #size-cells = <1>;
> >>
> >> partition at 0 {
> >>
> >> label = "u-boot";
> >> reg = <0x0000000 0x100000>;
> >> read-only;
> >>
> >> };
> >>
> >> uimage at 100000 {
> >>
> >> reg = <0x0100000 0x200000>;
> >>
> >> };
> >>
> >> };
> >>
> >> The parser ignores any flash without subnodes and returns 0 (no
> >> partititon). When there is a subnode it assumes the flash is
> >> partitioned and tries to parse the subnodes as partitions. When there
> >> are subnodes and none parses as partition an error is returned. As
> >> shown above it is valid to have subnodes on unpartitioned flash.
> >>
> >> When an error is returned from a partition parser the mtdpart code
> >> passes on this error to the flash probe function and the proble of the
> >> flash fails.
> >
> > What does /proc/mtd tell you when you have no partitions defined
> > in the DT ? It should provide you with the entire MTD device and
> > the code shouldn't even try to parse any OF partitions, since you
> > don't have any.
>
> mtdinfo shows I have no mtd devices and the log shows that probe
> failed unless I patch the kernel.
>
> When there is *support* for of partitions the ofparser is run on mtd
> probe. If it fails because it considers
>
> >> controller-data {
> >>
> >> samsung,spi-feedback-delay = <0>;
> >>
> >> };
>
> an invalid partition and does not find any valid partition the probe fails.
OK, now it has become clearer to me, thanks!
> There are two problems here
>
> 1) the above is not invalid. It just is not a partition. The parser
> should not fail seeing this
The parser should complain verbosely and ignore this I guess ?
> 2) the mtd probe should not fail when a partition parser fails and
> should present the unpartitioned device
OK
> Both are addressed in separate patches.
>
> Thanks
>
> Michal
next prev parent reply other threads:[~2015-06-05 14:13 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-03 21:26 [PATCH 00/11] Enable access to SPI NOR flash on Samsung Snow board Michal Suchanek
2015-06-03 21:26 ` [PATCH 01/11] ARM: dt: Add SPI CS " Michal Suchanek
2015-06-04 2:05 ` Krzysztof Kozlowski
2015-06-04 6:52 ` Javier Martinez Canillas
2015-06-03 21:26 ` [PATCH 02/11] mtd: spi-nor: Add GD25LQ32C 1.8V SPI NOR flash ID Michal Suchanek
2015-06-03 21:26 ` [PATCH 04/11] mtd: ofpart: do not fail probe when no partitions exist Michal Suchanek
2015-06-03 22:58 ` Marek Vasut
2015-06-04 4:54 ` Michal Suchanek
2015-06-04 15:28 ` Marek Vasut
2015-06-04 15:40 ` Michal Suchanek
2015-06-05 14:13 ` Marek Vasut [this message]
2015-06-23 18:26 ` Brian Norris
2015-06-03 21:26 ` [PATCH 05/11] mtd: mtdpart: Do not fail mtd probe when parsing partitions fails Michal Suchanek
2015-06-03 21:26 ` [PATCH 03/11] mtd: add debug prints to mtdpart partition parser Michal Suchanek
2015-06-03 21:26 ` [PATCH 06/11] mtd: spi-nor: rework spi nor read and write Michal Suchanek
2015-06-03 21:26 ` [PATCH 09/11] dma: pl330: fix wording in mcbufsz message Michal Suchanek
2015-06-04 2:10 ` Krzysztof Kozlowski
2015-06-08 11:07 ` Vinod Koul
2015-06-03 21:26 ` [PATCH 07/11] mtd: spi-nor: rework write loop Michal Suchanek
2015-06-03 21:26 ` [PATCH 08/11] MTD: m25p80: Add option to limit SPI transfer size Michal Suchanek
2015-06-03 23:03 ` Marek Vasut
2015-06-04 4:31 ` Michal Suchanek
2015-06-04 15:15 ` Marek Vasut
2015-06-04 6:42 ` Geert Uytterhoeven
2015-06-04 8:31 ` Michal Suchanek
2015-06-04 17:15 ` Richard Cochran
2015-07-15 9:45 ` Michal Suchanek
2015-07-15 11:52 ` Marek Vasut
2015-07-15 15:59 ` Brian Norris
2015-07-15 17:15 ` Marek Vasut
2015-07-16 1:19 ` Brian Norris
2015-07-16 1:44 ` Marek Vasut
2015-07-19 19:01 ` Michal Suchanek
2015-07-21 4:29 ` Vinod Koul
2015-07-21 8:14 ` Michal Suchanek
2015-07-22 4:49 ` Vinod Koul
2015-07-22 7:30 ` Michal Suchanek
2015-07-22 7:33 ` Marek Vasut
2015-07-22 7:45 ` Michal Suchanek
2015-07-22 7:58 ` Marek Vasut
2015-07-22 8:18 ` Michal Suchanek
2015-07-22 8:24 ` Marek Vasut
2015-07-22 8:38 ` Michal Suchanek
2015-07-22 9:01 ` Marek Vasut
2015-07-23 16:46 ` Michal Suchanek
2015-07-23 17:03 ` Michal Suchanek
2015-07-24 8:34 ` Marek Vasut
2015-07-24 11:20 ` Michal Suchanek
2015-07-27 9:46 ` Michal Suchanek
2015-07-27 17:43 ` Marek Vasut
2015-07-27 20:43 ` Michal Suchanek
2015-07-30 11:24 ` Marek Vasut
2015-07-30 12:18 ` Michal Suchanek
2015-07-30 12:33 ` Marek Vasut
2015-06-03 21:26 ` [PATCH 11/11] dt: Exynos: add Snow SPI NOR node Michal Suchanek
2015-06-04 2:04 ` Krzysztof Kozlowski
2015-06-04 15:20 ` Marek Vasut
2015-06-17 12:19 ` Pavel Machek
2015-06-03 21:26 ` [PATCH 10/11] spi: add more debug prints in s3c64xx Michal Suchanek
2015-06-03 23:04 ` Marek Vasut
2015-06-04 9:16 ` Mark Brown
2015-06-04 9:30 ` Geert Uytterhoeven
2015-06-04 9:42 ` Mark Brown
2015-06-04 9:33 ` Michal Suchanek
2015-06-04 10:26 ` Mark Brown
2015-06-04 10:52 ` Michal Suchanek
2015-06-04 10:56 ` Mark Brown
2015-06-03 22:53 ` [PATCH 00/11] Enable access to SPI NOR flash on Samsung Snow board Marek Vasut
2015-06-04 4:21 ` Michal Suchanek
2015-06-04 15:29 ` Marek Vasut
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201506051613.09187.marex@denx.de \
--to=marex@denx$(echo .)de \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox