JFFS2 impact when don't have sub page access

[Gupta, Pekon]

Hi,

> >
> >> Also, the subject talks about JFFS2. There is no known affect of absence
> >> of subpage support on JFFS2, right?
> >>
> > There should not be any problem in using either UBIFS or JFFS2.
> 
> Please, clarify me with the last statement.
> 
> There should be no problem using JFFS2 or UBIFS with the patch that you
> mention applied or even without the patch ?
> 

For UBIFS to work, 
(1) please check following options passed for mkfs.ubifs
- with this patch
mkfs.ubifs -s 512  -m 2048

- without this patch
mkfs.ubifs -s 2048  -m 2048

(2) Also please check for  'chip->options & NAND_NO_SUBPAGE_WRITE'.
This flag is used for explicitely _disabling_ sub-pages in NAND driver.


> With OMAP L138 are some complains about using the ubifs and subpage
> access, even on uboot [1] so it don't appear to be only a linux [2] problem.
> 
> And if the problems appear on ubifs it should affect the jffs2.
> 
> [1] - http://lists.denx.de/pipermail/u-boot/2011-April/090072.html
Yes, there is no subpage support in U-Boot.
Also I hope you are using 'ubiformat' to format the NAND partition with
UBI.img in kernel ? If that isn't the case, then I'm not sure what can be the
problem here.
I have tested omap2-nand with subpage enabled and 
using ubiformat. And it works fine.


> [2] - http://comments.gmane.org/gmane.linux.davinci/23836
>
Also from [2] last post, there seemed to be an issue with mis-match in 
ECC scheme used between U-Boot and ECC-scheme used in Kernel.
(But this has nothing todo with sub-pages)..
Your logs also show ECC errors, so I suggest please make sure you are
using same ECC scheme in kernel, as the one with which you flashed 
the image.
----------------------------------------
>> [  128.344667] UBI error: ubi_io_read: error -74 (ECC error) while 
>> reading 512 bytes from PEB 2:512, read 512 bytes
>> [  128.883945] UBI error: ubi_io_read: error -74 (ECC error) while 
>> reading 512 bytes from PEB 1766:512, read 512 bytes
>> [  128.884072] UBI: run torture test for PEB 1766
----------------------------------------


with regards, pekon