oobavail issues

[Joshua Wise]

Hi folks,

We're debugging a mysterious crash on NAND writes on an s3c2410-derived 
driver. The culprit seems to be in how oobavail is determined:

line 2524 nand_base.c: mtd->oobavail = mtd->oobsize - 
(this->autooob->eccbytes + 1);

Our oobinfo is the same as the s3c2410's. For reference, that's:

static struct nand_oobinfo nand_hw_eccoob = {
         .useecc = MTD_NANDECC_AUTOPLACE,
         .eccbytes = 3,
         .eccpos = {0, 1, 2 },
         .oobfree = { {8, 8} }
};

We found that making our oobfree match up with oobavail seemed to do the 
trick for avoiding this, and make JFFS2 work, to boot! Here's what we did:

static struct nand_oobinfo nand_hw_eccoob = {
         .useecc = MTD_NANDECC_AUTOPLACE,
         .eccbytes = 3,
         .eccpos = {0, 1, 2 },
         .oobfree = { {8, 8}, {3, 2}, {6, 2} } /* {6, 10} instead? */
};

I suspect that oobavail should be summing oobfree instead of doing that 
arithmetic. Or is there something I'm not seeing?

joshua