[U-Boot] NOR NAND Interference question

[Andrei <ayakimov@iptec-inc.com>]

Hi,
 Recently I am start getting strange problem
with u-boot-2011.09. MPC8313ERDB like
configuration ( main change - I am using 
different NAND flash - 256MBib - need change
page size)

If I am access NAND flash before nor
u-boot not always read NOR correctly.

>mtdparts 

device nor0 <phys_mapped_flash>, # parts = 3
 #: name                size            offset          mask_flags
 0: u-boot              0x000e0000      0x00000000      0
 1: env                 0x00020000      0x000e0000      0
 2: jffs2               0x01f00000      0x00100000      0

device nand0 <e2800000.flash>, # parts = 1
 #: name                size            offset          mask_flags
 0: ubifs               0x10000000      0x00000000      0

If I do:
ubi part ubifs;ubifsmount iptec_nand

and read something from NAND before I read NOR

I am getting time to time after Linux update 
uImage: 

>run boot_cmd
### JFFS2 loading 'BANK1/uImage' to 0x100000
Scanning JFFS2 FS: . done.
### JFFS2 load complete: 4926025 bytes loaded to 0x100000
### JFFS2 loading 'BANK1/vnp100_dtb.dtb' to 0x900000
### JFFS2 load complete: 10205 bytes loaded to 0x900000
## Booting kernel from Legacy Image at 00100000 ...
   Image Name:   Linux-2.6.38.8
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    4925961 Bytes = 4.7 MiB
   Load Address: 02000000
   Entry Point:  02000000
   Verifying Checksum ... Bad Data CRC
ERROR: can't get kernel image!

but if I reset board and skip NAND access 
it always fine, some times I can add or remove
some environment variable after NAND access
and it boot even without reset:

>run boot_cmd
### JFFS2 loading 'BANK1/uImage' to 0x100000
Scanning JFFS2 FS: . done.
### JFFS2 load complete: 4926025 bytes loaded to 0x100000
### JFFS2 loading 'BANK1/vnp100_dtb.dtb' to 0x900000
### JFFS2 load complete: 10205 bytes loaded to 0x900000
## Booting kernel from Legacy Image at 00100000 ...
   Image Name:   Linux-2.6.38.8
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    4925961 Bytes = 4.7 MiB
   Load Address: 02000000
   Entry Point:  02000000
   Verifying Checksum ... OK
## Flattened Device Tree blob at 00900000
   Booting using the fdt blob at 0x900000
   Uncompressing Kernel Image ... OK
   Loading Device Tree to 007fa000, end 007ff7dc ... OK

I found most stable configuration:
mount NAND, read NAND,
chaprt nor0,2
boot

and most unstable
chaprt nor0,2
mount NAND, read NAND,
boot

And I did increase malloc size to 1M.( ubifs does not like 128K).
There is no option for stack size  - it is PPC,
so it should grow down as needed.

As long I am not mixing NOR and NAND evithing working perfect.

Any idea?

Thanks,
Andrei