Hello,

Well I should have looked up where the "uncorrectable error" was coming from 
before sending out this email. It looks like the MTD layer is getting multi-bit 
errors and hence can't correct the error. It's kind of interesting that the ECC 
failures don't affect the data I wrote, that is I can read back the data 
properly. The other interesting thing I noticed is the sectors where the 
failures occur appear to be multiples of 8?

Eddie Dawydiuk wrote:
> Hello,
> 
> I'm running a 2.6.28 Linux kernel with Yaffs2(checked out 04/22/2009). 
> Were using a 512 MB (2K sector) nand flash chip and I'm currently in the 
> testing phase. I've found if I transfer large files (approx 400MB) I get 
> the following errors when I remount the Yaffs filesystem.
> 
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 0
> __ratelimit: 11 callbacks suppressed
> Buffer I/O error on device mtdblock3, logical block 0
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 8
> Buffer I/O error on device mtdblock3, logical block 1
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 16
> Buffer I/O error on device mtdblock3, logical block 2
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 24
> Buffer I/O error on device mtdblock3, logical block 3
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 32
> Buffer I/O error on device mtdblock3, logical block 4
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 40
> Buffer I/O error on device mtdblock3, logical block 5
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 48
> Buffer I/O error on device mtdblock3, logical block 6
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 56
> Buffer I/O error on device mtdblock3, logical block 7
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 64
> Buffer I/O error on device mtdblock3, logical block 8
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 72
> Buffer I/O error on device mtdblock3, logical block 9
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 80
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 88
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 96
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 104
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 112
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 120
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 128
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 0
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 528
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 528
> uncorrectable error : <3>end_request: I/O error, dev mtdblock3, sector 528
> 
> The large file reads back correctly though(no data corruption). Has 
> anyone else seen any similiar failures or have any pointers? I've turned 
> on Yaffs tracing but it's no help seeing as though these messages are 
> not coming from Yaffs...
> 
> 
> I'm not sure if MTD would be a more appropriate list to post this to...?
> 


-- 
Best Regards,
________________________________________________________________
  Eddie Dawydiuk, Technologic Systems | voice:  (480) 837-5200
  16525 East Laser Drive 	     | fax:    (480) 837-5300
  Fountain Hills, AZ 85268            | web: www.embeddedARM.com