Re: [BUG] pxa3xx: wait time out when scanning for bb

[Miquel RAYNAL <miquel.raynal@free-electrons.com>]

Hi Sean,


> >> I had a look at it and I have rebased my stuff on top of your
> >> branch. I have edited my devicetree to look like this:
> >> &nand_controller {
> >>       status = "okay";
> >>       pinctrl-names = "default";
> >>       pinctrl-0 = <&nand_pins>, <&nand_rb>;
> >>
> >>       nand@0 {
> >>           reg = <0>;
> >>           label = "pxa3xx_nand-0";
> >>           marvell,rb = <0>;
> >>           marvell,nand-keep-config;
> >>           nand-on-flash-bbt;
> >>           nand-ecc-strength = <4>;
> >>           nand-ecc-step-size = <512>;
> >>       };
> >> };
> >>
> >> It produces a lot of bad eraseblocks entrys
> >> [    2.693343] nand: device found, Manufacturer ID: 0x2c, Chip ID:
> >> 0xda [    2.699717] nand: Micron MT29F2G08ABAEAH4
> >> [    2.703772] nand: 256 MiB, SLC, erase size: 128 KiB, page size:
> >> 2048, OOB size: 64
> >> [    2.714286] Bad block table not found for chip 0
> >> [    2.721509] Bad block table not found for chip 0
> >> [    2.726139] Scanning device for bad blocks
> >> [    2.730583] Bad eraseblock 0 at 0x000000000000
> >> [    2.735365] Bad eraseblock 1 at 0x000000020000
> >> [    2.740145] Bad eraseblock 2 at 0x000000040000
> >> [    2.744934] Bad eraseblock 3 at 0x000000060000
> >> [    2.749714] Bad eraseblock 4 at 0x000000080000
> >>
> >> Is my devicetree correct?  
> > It depends:
> >    - Did you already use bad block tables before ?  
> Yes because if I don't i would get the timeouts described in this
> thread :-)

Actually, if you look carefully to the trace behind, you are not using
the same bad block table with the bootloader ("Bad block table not
found for chip 0") so the core then reads the OOB area of every first
page for each block and looks at the first OOB bytes for the bad block
markers. If there was data there, the block will be declared as bad.

Can you please check that by using the configuration that actually
boots and use nanddump in raw mode with the OOB area (options -n and -o)
to show us the content of the first page of any block of the last NAND
MTD device?


> >    - Is your bootloader using 4b/512B ECC strength ?  
> strength 4, ecc_stepsize 512, page_size 2048 but the uboot driver
> sets it to strength 16, ecc_stepsize 512, page_size 2048,
> just like the current pxa3xx driver in the kernel does.
> >
> > Besides:
> >
> >    - What filesystem are you booting? Is it UBIFS or JFFS2 or
> > something else?  
> UBI
> >    - Did you show the 5 first bad eraseblocks only or all of them?  
> It continues to count to:
> Bad eraseblock 2047 at 0x00000ffe0000
> >    - Do you have good blocks ?  
> No
> >    - Can you make use of the NAND chip after?  
> No
> 
> Correct me if i'm wrong, but i can't find anywhere the 
> nand-ecc-step-size is read by the new nand driver?

The core does (nand_scan_tail -> nand_dt_init ->
of_get_nand_ecc_step_size).


Thanks,
Miquèl