impact of 2X_PROGRAM on read operations

David Wagner david.wagner at
Thu Jun 9 08:44:46 EDT 2011

On 06/06/2011 04:32 PM, Artem Bityutskiy wrote:
> On Mon, 2011-06-06 at 14:12 +0200, David Wagner wrote:
>> Is there a way to safely read without 2X_PROGRAM enabled once it has
>> been flashed with a 2X_PROGRAM-enabled flasher (e.g. patched u-boot).
> Not sure about u-boot, but AFAIK 2x is a completely separate mode which
> gives you I/O speed-up but makes things incompatible with "normal" mode.
> E.g., you can mount JFFS2 only in one of the modes.

Ok, so I guess it doesn't make sense trying to address the issue of

I may have to check once again, but I'm pretty sure, however, that I
managed to flash a UBI image with a 2X_PROGRAM-enabled u-boot and read
it with a regular kernel. The u-boot code for 2X_PROGRAM handling seems
to basically be a copy-paste from the kernel.
If the diagram in my first mail is correct, that could not be possible.

Kyungmin, do you know what's wrong in my reasoning ?

David Wagner.
David Wagner, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.

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