I would like to submit that the patch below might be appropriate for those 
who aren't paranoid about ECC errors on read-back contributing to a greater 
chance of future data loss in that block.

Charles, is there anything I've missed?

--MichaeL

--- yaffs_tagscompat-old.c 2006-02-10 16:37:01.000000000 -0700
+++ yaffs_tagscompat.c 2006-02-10 16:37:04.000000000 -0700
@@ -335,6 +335,7 @@

 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND)
 {
+#ifdef PARANOID_ABOUT_READ_ERRORS
  int blockInNAND = chunkInNAND / dev->nChunksPerBlock;

  /* Mark the block for retirement */
@@ -347,6 +348,7 @@
   * then retire the block
   * NB recursion
   */
+#endif
 }

 #ifdef NOTYET