Unstable bit issue with UBIFS on NAND for AM3352 design

John J Wu

I’m wondering if you know whether the unstable bit issue with UBIFS on NAND flash (http://www.linux-mtd.infradead.org/doc/ubifs.html#L_unstable_bits) has been resolved as TI is pushing for using UBIFS (http://processors.wiki.ti.com/index.php/AM335x_JFFS2_Support_Guide#Reasons_for_disabling_JFFS2_support).

over 11 years ago

0 Miroslav Kiradzhiyski XID over 11 years ago

TI__Mastermind 25235 points

Hi John,

I'll ask the factory team about this.

Best regards,
Miroslav

0 Wolfgang Muees1 over 11 years ago

Genius 3685 points

As program and erase times of NAND flashes are short, you can very easy add an extra VCC buffering capacitor (and a decoupling diode). And you will never see this sort of failure in your device.

regards

Wolfgang

0 John J Wu over 11 years ago in reply to Miroslav Kiradzhiyski XID

Genius 3870 points

Any update from the factory, Miroslav?

Thanks,

John

0 Miroslav Kiradzhiyski XID over 11 years ago in reply to John J Wu

TI__Mastermind 25235 points

Sorry, not yet. I suppose someone will post directly in this thread.

Best regards,
Miroslav

0 RonB over 11 years ago

TI__Mastermind 30746 points

John,

In short, no, TI has not done anything above what the Linux community provides. The community has so far elected not to pursue this issue any further.

We recommend UBIFS because we feel it is the best FS option for non-managed NAND. There are other options, and it is up to system developers to choose what makes the best choice for their particular circumstance.

If this issue is a major concern, then a system level solution that involves protecting from power failures during flash writes or keeping redundant backups as best as possible. A lot of customers implement a "golden image" type of scheme.

0 HYOUCK KIM over 9 years ago in reply to Wolfgang Muees1

Prodigy 20 points

can you please provide us with a sample schematic for the vcc buffering capacitor/decoupling diode? I, as my self, am very interested in this unstable bits issue and , as a software engineer, it is not easy to come up with h/w schematic myself. It would be a great reference.

regards

H.Kim

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Unstable bit issue with UBIFS on NAND for AM3352 design