Re: [Bug] mtd: rawnand: gpmi

[Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>]

On Tue, Sep 10, 2019 at 01:00:30PM +0200, Sean Nyekjaer wrote:
> 
> 
> On 10/09/2019 12.48, Sascha Hauer wrote:
> > On Tue, Sep 10, 2019 at 12:18:25PM +0200, Sean Nyekjaer wrote:
> > > 
> > > 
> > > On 10/09/2019 11.55, Sascha Hauer wrote:
> > > > > [    2.434057] Bad block table written to 0x00001ffc0000, version 0x01
> > > > > [    2.437254] Bad block table written to 0x00001ff80000, version 0x01
> > > > What about this "Bad block table written" message? You should see this
> > > > exactly once. Do you see this multiple times, especially when switching
> > > > kernels between the good one and the bad one?
> > > > 
> > > > Sascha
> > > 
> > > Not exactly sure what you mean, but here is the dumps:
> > > 
> > > Before (mtd: rawnand: gpmi: Implement exec_op)
> > > [    3.389352] Bad block table written to 0x00001ffc0000, version 0x01
> > > [    3.399019] Bad block table written to 0x00001ff80000, version 0x01
> > > 
> > > After
> > > [    3.301096] Bad block table written to 0x00001ffc0000, version 0x01
> > > [    3.310599] Bad block table written to 0x00001ff80000, version 0x01
> > 
> > The Bad block table is written once. When you see this message multiple
> > times then this means that Linux can't read the BBT and writes it again.
> > So the question is: Start the good kernel multiple times. Do you see
> > this message once or on each boot? Then start the bad Kernel multiple
> > times. Do you see the message once or on each boot?
> > 
> > Sascha
> > 
> 
> U-boot:
> => nand erase.chip
> 
> NAND erase.chip: device 0 whole chip
> Skipping bad block at  0x0c780000
> Skipping bad block at  0x18000000
> Skipping bad block at  0x18040000
> Skipping bad block at  0x1ff00000
> Skipping bad block at  0x1ff40000
> Skipping bad block at  0x1ff80000
> Skipping bad block at  0x1ffc0000
> 
> Look weird it marks the bbt location bad ?

Yes, that's normal. The BBT itself is marked as bad. Otherwise the they
would just be used by regular mtd users.

> Or is it a uboot feature?
> I have tried another board, and uboot marks the bbt location bad on that as
> well
> 
> First boot:
> [    4.149870] nand: device found, Manufacturer ID: 0x98, Chip ID: 0xdc
> 
> 
> [    4.156589] nand: Toshiba NAND 512MiB 3,3V 8-bit
> [    4.161500] nand: 512 MiB, SLC, erase size: 256 KiB, page size: 4096, OOB
> size: 128
> 
> [    4.175918] Bad block table not found for chip 0
> [    4.184059] Bad block table not found for chip 0
> [    4.188808] Scanning device for bad blocks
> [    4.690183] Bad eraseblock 798 at 0x00000c780000
> [    5.155504] Bad eraseblock 1536 at 0x000018000000
> [    5.161008] Bad eraseblock 1537 at 0x000018040000
> [    5.487883] Bad block table written to 0x00001ffc0000, version 0x01

And is this the bad kernel or the good kernel? The question I am trying
to answer is: Can the good kernel read the BBT it has written? Can the
bad Kernel do that?

Sascha

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