[mtd] possible bug in nandsim

[Ezequiel Garcia]

Hello Richard, Tanya:

On Thu, Nov 07, 2013 at 03:35:30PM +0100, Richard Weinberger wrote:
> On Thu, Nov 7, 2013 at 12:43 PM, Tanya Brokhman <tlinder at codeaurora.org> wrote:
> > Hi
> >
> > I've recently started working with the nand simulator. For my testing
> > purposes I have to use it with a cache file. Bellow are the commands I run:
> >
> > modprobe nandsim first_id_byte=0x20 second_id_byte=0xaa third_id_byte=0x00
> > fourth_id_byte=0x15 cache_file=cache_file.txt
> > modprobe ubi mtd=0 fm_autoconvert=1
> >
> > Unfortunately, when trying the above I noticed that the next time i load
> > nandsim and ubi on top of it the fastmap data is not saved at cache_file.txt
> > and the device comes up as clean. Meaning, the cache file feature of the
> > nandsim isn't working properly.
> 
> IIRC this feature is really meant as a cache and not persistent storage.
> 

AFAIK Richard is right, the feature is just a non-persistent cache.

However a patch was submitted (and never reviewed) recently to
apparently add persistent behavior:

  http://patchwork.ozlabs.org/patch/277974/

Tanya: Can you test or review the patch and provide a formal
Tested/Reviewed-by? I'd be interested in seeing that move forward :)

Thanks!
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com