On Tue, Oct 14, 2014 at 04:50:27PM +1100, Iwo Mergler wrote:

quoted

No, it doesn't seem to be correct.
But it's an MLC flash, so you'll most probably need to apply this patch
to nandbiterrs testsuite:

http://code.bulix.org/f69wuu-87021

This patch is flashing the block between each bitflip insertion to
avoid multiple write without erasure (which, AFAIK, is not supported
by MLC flashes).

Hi Huang,


just out of interest, have you tried this on the MLC NAND without the patch?

I'm aware that MLC says you shouldn't write multiple times, but that is
with a view towards specified data endurance. I would only expect a few
additional bit errors during the test.

Did you try the overwrite test?

The following is the test result for overwrite with this MLC patch:

root at imx6qdlsolo:~# insmod mtd_nandbiterrs.ko dev=1 mode=1
[  762.534714] 
[  762.536259] ==================================================
[  762.542115] mtd_nandbiterrs: MTD device: 1
[  762.546326] mtd_nandbiterrs: MTD device size 16777216,
	eraseblock=2097152, page=8192, oob=744
	[  762.554937] mtd_nandbiterrs: Device uses 1 subpages of 8192
	bytes
	[  762.561059] mtd_nandbiterrs: Using page=0, offset=0,
	eraseblock=0
	[  762.571333] mtd_nandbiterrs: overwrite biterrors test
	[  762.576715] mtd_nandbiterrs: write_page
	[  762.590448] mtd_nandbiterrs: error: read failed at 0x0
	[  762.595650] mtd_nandbiterrs: Read reported error -74
	[  762.600625] mtd_nandbiterrs: Bit error histogram (0
			operations total):
	[  762.608586] mtd_nandbiterrs: finished successfully.
	[  762.613501]
	==================================================
	insmod: ERROR: could not insert module mtd_nandbiterrs.ko:
	Input/output error


thanks	   

Huang Shijie