#1905 BLOC Trial-3: Field Return: flash corruption - OpenFirmware complaining of 'unknown node type 2006'.

[Zarro Boogs per Child]

#1905: Field Return: flash corruption - OpenFirmware complaining of 'unknown node
type 2006'.
-----------------------+----------------------------------------------------
  Reporter:  dwmw2     |       Owner:  dwmw2  
      Type:  defect    |      Status:  new    
  Priority:  blocker   |   Milestone:  Trial-3
 Component:  hardware  |     Version:         
Resolution:            |    Keywords:         
  Verified:  0         |  
-----------------------+----------------------------------------------------
Changes (by dwmw2):

  * component:  kernel => hardware

Comment:

 Replying to [comment:33 Luna]:
 >  Problem 2: ( Use two new Nand flash chips on the same machine to test)
 >
 > I used two methods for the first chip:
 >
 >   (1) Put the chip into the ST nand flash test machine which comes from
 ST Cor. to get the initial bad block table which has 16 initial bad
 blocks.
 >
 >   (2) Solder the chip on the board first. Boot OLPC to OFW and execute
 command "select /nand " "scrub" "test /nandflash" in order.
 >       It comes out 5 bad blocks only to skip and the BBTables is set on
 the latest two blocks (0x1ffe 0x1fff)

 You should _never_ use 'scrub'. That destroys the factory-marked bad block
 information.

 >   (3) Then I move the chip into the ST nand flash test machine and
 scanned it again.
 >       There are 7 bad blocks in the chip. You can see the attachment
 (problem2chip1-1,problem2chip1-2) to get the bad address.

 Your second image shows only 5 bad blocks (and two blocks set aside for
 BBT).
 So only 5 of the original 16 bad blocks are still correctly marked bad.

 > The second chip: (attachment: problem2chip2-1 ~ problem2chip2-3)
 >
 >   (1) Put another new chip into the ST nand flash test machine to get
 the initial bad block table which has one bad block (0x069e).
 >
 >   (2) Solder the chip on the board first. Boot OLPC to OFW and execute
 command "test /nandflash". It comes out 1 bad block (0x069e) and BBTable
 is also set on the latest two blocks
 >
 >   (3) Then I boot from USB. Execute command "flash_eraseall -j
 /dev/mtd0" to get the result with four more bad blocks (0x3ff80000
 0x3ffa0000 0x3ffc000 0x3ffe000).

 Two of those are the bad block table. I'm not entirely sure why four
 blocks end up being used, but it'll be related to the bad block table.
 I'll try to investigate. It isn't related to this trac issue.

 >   (4) Reboot OLPC to OFW to execute command "test /nandflash". Get one
 bad block (0x069e).
 >
 >   (5) Execute command "select /nand " "scrub" "test /nandflash" in
 order. It comes out no bad block and BBTable is set on the latest two
 blocks.

 Again, you've lost information by using 'scrub'. Never do that.

-- 
Ticket URL: <https://dev.laptop.org/ticket/1905#comment:36>
One Laptop Per Child <http://laptop.org/>