Hello，my kernel version is 2.6.12, my yaffs versionis "$Id: yaffs_checkptrw.c,v 1.15 2007-12-13 15:35:17 wookey Exp $", my nand flash model is S34ML08G. In the kernel, I was able to mount successfully. However, an error occurred while creating the file. 
E.g: 
mkdir test
**>> yaffs chunk 256 was not erased
**>> yaffs chunk 320 was not erased
**>> yaffs chunk 384 was not erased
**>> yaffs chunk 448 was not erased
**>> yaffs chunk 512 was not erased
**>> yaffs write required 7 attempts
I reboot the kernel, The test does not exist. 
If you have encountered, help me.  thank you very much.