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Arnd Bergmann | 1 Jan 2007 23:22
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Re: [RFC] MTD driver for MMC cards

On Sunday 31 December 2006 13:32, Pierre Ossman wrote:
> Arnd Bergmann wrote:
>
> I'm a complete MTD noob, but what uses does the MTD layer have besides
> JFFS2. If it's none, than this advantage isn't that big of a deal. 
>
> > * It becomes possible to use MMC cards with jffs2 even with CONFIG_BLOCK
> >   disabled, which can save a significant amount of kernel memory on
> >   small machines that have an MMC slot but no other block device.
> > 
> 
> From what I've heard, JFFS2 is close to unusuable on the sizes of modern
> SD/MMC cards. So I'd like to see some more use cases before I'm ready
> to let this in.  

There are multiple efforts in progress to get a jffs2 replacement. NAND
flash in embedded devices has the same size as it has on MMC card
potentially, so we will need one soon. David Woodhouse has pushed the
limit that jffs2 can reasonably used to 512MB, which is the size used
in the OLPC XO laptop. If there are ways to get beyond that (which I
find unlikely), there will be a hard limit 2GB or 4GB because of
limitations in the fs layout.

One promising effort for a replacement is Jörn's logfs
(http://wiki.laptop.org/go/Logfs), which should scale well to many
gigabytes. A driver based on MMC would be a nice development tool
for that, since it enables regular PCs as a debugging machine
instead of having to load test kernels onto an actual embedded
machine.
(Continue reading)

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David Woodhouse | 2 Jan 2007 01:08
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Re: [RFC] MTD driver for MMC cards

On Mon, 2007-01-01 at 23:22 +0100, Arnd Bergmann wrote:
> There are multiple efforts in progress to get a jffs2 replacement. NAND
> flash in embedded devices has the same size as it has on MMC card
> potentially, so we will need one soon. David Woodhouse has pushed the
> limit that jffs2 can reasonably used to 512MB, which is the size used
> in the OLPC XO laptop. If there are ways to get beyond that (which I
> find unlikely), there will be a hard limit 2GB or 4GB because of
> limitations in the fs layout.

The main weakness of JFFS2 (at this kind of size) is that there _is_ no
fs layout -- so there isn't a hard 2GiB or 4GiB limit in the format,
because we never encode offsets anywhere but in memory.

We'll push JFFS2 further than the current 512MiB by enlarging the data
nodes -- so each node covers something like 16KiB of data instead of
only 4KiB, and then there'll be about 1/3 as many of them, which will
cut the memory usage and reduce the amount we need to read in the
"summary" blocks. But logfs is the way forward, I agree.

--

-- 
dwmw2

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Adrian Hunter | 2 Jan 2007 09:05
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Re: onenand_wait and onenane_read

Thanks for looking at this.

Note that after the patch, onenane_wait seems to return non-zero even
when the error is corrected by ecc.  Shouldn't it return zero in that
case?

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Artem Bityutskiy | 2 Jan 2007 10:37
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OneNAND

Hello Kyungmin,

I do not agree with this patch on your OneNAND tree:
564bdb30743e5a85ede4b9fd0cdb24228d902c37

Also this patch is not good in my opinion:
a75603c07553fdcf87f8c658ccdf0508f3b591cd

We have more OneNAND patches which were not sent yet so I decided to
maintain my own OneNAND tree. As I do not agree with some of your
patches I based it on mtd-2.6.git for now.

--

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)

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Nathan Edson | 2 Jan 2007 14:14

DiskOnChip

Hello!

I'm trying to get a diskonchip2000 mounted and
working...

I have a couple Wyse Winterm thin clients with
96mb DOC's.  I'm booting them off the network
using Knoppix.  They don't have any other drives.
So far, I've tried:

modprobe doc2000
modprboe docprobe

After doing docprobe I get an error that the device
is temporarily unvailable.  When I dmesg I see
that the device has been identified.  I've tried mknod
and then mounting the chips with no success.

The knoppix disc I'm using uses kernel 2.6.17.

Any ideas?  Thanks in advance!

Nathan

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Josh Boyer | 2 Jan 2007 15:05
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Re: OneNAND

On Tue, 2007-01-02 at 11:37 +0200, Artem Bityutskiy wrote:
> Hello Kyungmin,
> 
> I do not agree with this patch on your OneNAND tree:
> 564bdb30743e5a85ede4b9fd0cdb24228d902c37
> 
> Also this patch is not good in my opinion:
> a75603c07553fdcf87f8c658ccdf0508f3b591cd

Explaining why you don't like them would help

josh

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Indrek Kruusa | 2 Jan 2007 15:21
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[PATCH] [MTD] cs553x_nand.c: support partitions; cs553x_cleanup() fix

Hi!

Patch for drivers/mtd/nand/cs553x_nand.c:
- support partitions
- cs553x_cleanup(): try the cleanup for all chip selects

Signed-off-by: Indrek Kruusa <indrek.kruusa <at> artecdesign.ee>

--- cs553x_nand.c_git	2007-01-02 15:13:06.000000000 +0200
+++ cs553x_nand.c	2007-01-02 15:45:38.000000000 +0200
 <at>  <at>  -273,12 +273,21  <at>  <at> 
 	return 0;
 }

+
+#ifdef CONFIG_MTD_PARTITIONS
+const char *part_probes[] = { "cmdlinepart", NULL };
+#endif
+
+
 static int __init cs553x_init(void)
 {
 	int err = -ENXIO;
 	int i;
 	uint64_t val;

+	int mtd_parts_nb = 0;
+	struct mtd_partition *mtd_parts = 0;
+
 	/* If the CPU isn't a Geode GX or LX, abort */
(Continue reading)

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Josh Boyer | 2 Jan 2007 15:40
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Re: [PATCH] [MTD] cs553x_nand.c: support partitions; cs553x_cleanup() fix

On Tue, 2007-01-02 at 16:21 +0200, Indrek Kruusa wrote:
> Hi!
> 
> Patch for drivers/mtd/nand/cs553x_nand.c:
> - support partitions
> - cs553x_cleanup(): try the cleanup for all chip selects

Some small nit picks.

> 
> Signed-off-by: Indrek Kruusa <indrek.kruusa <at> artecdesign.ee>
> 
> 
> --- cs553x_nand.c_git	2007-01-02 15:13:06.000000000 +0200
> +++ cs553x_nand.c	2007-01-02 15:45:38.000000000 +0200

Patches should have a strip level of 1.

>  <at>  <at>  -273,12 +273,21  <at>  <at> 
>  	return 0;
>  }
> 
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> +const char *part_probes[] = { "cmdlinepart", NULL };
> +#endif
> +
> +
>  static int __init cs553x_init(void)
>  {
(Continue reading)

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Indrek Kruusa | 2 Jan 2007 16:35
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Re: [PATCH] [MTD] cs553x_nand.c: support partitions; cs553x_cleanup() fix

On Tue, 02 Jan 2007 08:40:58 -0600
Josh Boyer <jwboyer <at> linux.vnet.ibm.com> wrote:

> On Tue, 2007-01-02 at 16:21 +0200, Indrek Kruusa wrote:
> > Hi!
> > 
> > Patch for drivers/mtd/nand/cs553x_nand.c:
> > - support partitions
> > - cs553x_cleanup(): try the cleanup for all chip selects
> 
> Some small nit picks.
> 
> > 
> > Signed-off-by: Indrek Kruusa <indrek.kruusa <at> artecdesign.ee>
> > 
> > 
> > --- cs553x_nand.c_git	2007-01-02 15:13:06.000000000 +0200
> > +++ cs553x_nand.c	2007-01-02 15:45:38.000000000 +0200
> 
> Patches should have a strip level of 1.

Oh my, sure. I will resend the patch.

> 
> >  <at>  <at>  -273,12 +273,21  <at>  <at> 
> >  	return 0;
> >  }
> > 
> > +
> > +#ifdef CONFIG_MTD_PARTITIONS
(Continue reading)

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Silvan Minghetti | 3 Jan 2007 07:34
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Re: LogFS


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