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NAND ecc error in T1022

Question asked by Debdutta Banerjee on Mar 2, 2020
Latest reply on Apr 29, 2020 by Debdutta Banerjee

Custom board based on T1022.

Nand flash:  MT29F32G08ABAAAWP-Z:A

Page size = 8192; Block size = 1024KiB; Block count = 4096, Memory size = 4096MiB, 8-bit ECC

 

filesystem: ubifs used as root

 

The file system mounts properly without any error. But on certain occasions (randomly) we are getting these errors:

 

UBIFS error (ubi0:0 pid 1881): try_read_node: cannot read node type 1 from LEB 17:803080, error -74
fsl,ifc-nand fff800000.nand: NAND Flash ECC Uncorrectable Error
ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 2590 bytes from PEB 19:819464, read only 2590 bytes, retry
fsl,ifc-nand fff800000.nand: NAND Flash ECC Uncorrectable Error
ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 2590 bytes from PEB 19:819464, read only 2590 bytes, retry
fsl,ifc-nand fff800000.nand: NAND Flash ECC Uncorrectable Error
ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 2590 bytes from PEB 19:819464, read only 2590 bytes, retry
fsl,ifc-nand fff800000.nand: NAND Flash ECC Uncorrectable Error
ubi0 error: ubi_io_read: error -74 (ECC error) while reading 2590 bytes from PEB 19:819464, read 2590 bytes
CPU: 1 PID: 1881 Comm: ls Tainted: P O 4.1.8-rt8 #19
Call Trace:
[e64f9a50] [c0676320] dump_stack+0x78/0xa0 (unreliable)
[e64f9a60] [c03af988] ubi_io_read+0x218/0x400@@@@#@
[e64f9ac0] [c03acdb0] ubi_eba_read_leb+0x150/0x480
[e64f9b10] [c03abe80] ubi_leb_read+0xb0/0x150
[e64f9b40] [c022cc30] ubifs_leb_read+0x30/0xa0
[e64f9b70] [c022ed68] ubifs_read_node+0xa8/0x380
[e64f9ba0] [c0252a50] ubifs_tnc_read_node+0x190/0x200
[e64f9c00] [c023338c] ubifs_tnc_locate+0x1cc/0x210
[e64f9c50] [c0222a70] do_readpage+0x1e0/0x5d0
[e64f9cb0] [c022412c] ubifs_readpage+0x4c/0x490
[e64f9d10] [c00c33c8] filemap_fault+0x2f8/0x4b0
[e64f9d50] [c00e60f4] __do_fault+0x44/0xc0
[e64f9d80] [c00e9ffc] handle_mm_fault+0xa7c/0xf00
[e64f9e00] [c0016a94] do_page_fault+0x2e4/0x620
[e64f9e40] [c000fb1c] handle_page_fault+0xc/0x80
--- interrupt: 301 at do_page_fault+0x3a0/0x620
LR = handle_page_fault+0xc/0x80
[e64f9f00] [00000000] (null) (unreliable)
[e64f9f40] [c000fb1c] handle_page_fault+0xc/0x80
--- interrupt: 401 at 0x1000b320
LR = 0x10002f30
UBIFS error (ubi0:0 pid 1881): ubifs_read_node: bad node type (55 but expected 1)
UBIFS error (ubi0:0 pid 1881): ubifs_read_node: bad node at LEB 17:803080, LEB mapping status 1
Not a node, first 24 bytes:
00000000: 37 3f 37 37 bf bf bf 37 37 3f 37 37 37 37 37 37 3f 3f 37 37 37 37 37 37 7?77...77?777777??777777
CPU: 1 PID: 1881 Comm: ls Tainted: P O 4.1.8-rt8 #19
Call Trace:
[e64f9b60] [c0676320] dump_stack+0x78/0xa0 (unreliable)
[e64f9b70] [c022efb8] ubifs_read_node+0x2f8/0x380

 

1. nanddump of the first few pages of the partition we see that they are all 0x37 or 3f or 0xbf and like wise.

2. On next boot-up there are no errors and filesystem mounts without any error. Nanddump show valid pages.

3. We are not certain what causes this error.

4. From the error and nanddump it seems, that since all the data are corrupted, ECC uncorrectable error is coming on nand read.

 

PFA schematic, pls give your suggestions.

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