[Ltib] RE: JFFS2 crc errors

[Chris Westervelt]

No I  just made some changes to the rootfs and saved them back.  After a power down and reboot, it started reporting this.  The product cannot be software shut down and must tolerate abrupt power loss.  If that is something we must consider in design then I need to get any appropriate changes made to the hardware/software to correct or tolerate this condition.  This is not the first time I have seen this in fact it almost always happens when we change the rootfs in any way.  I just wanted to better understand it and make sure it’s not a problem.

 

 

From: Kevin Wells [mailto:address@hidden
Sent: Wednesday, August 04, 2010 3:53 PM
To: Chris Westervelt; address@hidden
Subject: RE: JFFS2 crc errors

 

Hi Chris,

 

This can happen if something is writing to the NAND when the system is abruptly powered off or reset. Only part of the data will have been written to NAND.

Was the board shut down with the ‘reboot’ or ‘poweroff’ commands? This should give you a safe shutdown of JFFS2. An abrupt power cycle or reset can lead to issues with JFFS2 data (similar to any file system).

 

thanks,

Kevin

 

 

Subject: [Ltib] JFFS2 crc errors

 

All,

 

I have started the phase of our project where we are weaning off NFS and using JFFS2.  Now my understanding is the flash should work just like a normal drive but I am seeing errors about failed CRCs that I don’t understand.  Is this normal or do we have a real problem here?  Also, if it is normal, is there a way to suppress these messages and or automatic checks.  The following is what I see.

 

address@hidden /]# JFFS2 notice: (309) check_node_data: wrong data CRC in data node at 0x01dd4000: read 0x971bfcf, calculated 0xe401df4b.

JFFS2 notice: (309) check_node_data: wrong data CRC in data node at 0x01dd59b0: read 0x7299d564, calculated 0x4a339945.

 

Chris Westervelt

Senior Product Development Engineer

Infrasafe, Inc.
12612 Challenger Pkwy
Suite 300
Orlando, FL
32826

http://www.infrasafe.com
Office:   (407) 926-6983

Mobile: (407) 595-7023       
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