[MTD] [NAND] remove len/ooblen confusion.

As was discussed between Ricard Wanderlöf, David Woodhouse, Artem 
Bityutskiy and me, the current API for reading/writing OOB is confusing. 

The thing that introduces confusion is the need to specify ops.len 
together with ops.ooblen for reads/writes that concern only OOB not data 
area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to 
specify the length of the data read, and when ops.datbuf == NULL, it 
serves to specify the full OOB read length.

The patch inlined below is the slightly updated version of the previous 
patch serving the same purpose, but with the new Artem's comments taken 
into account.

Artem, BTW, thanks a lot for your valuable input!

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/drivers/mtd/nftlcore.c b/drivers/mtd/nftlcore.c
index d974adab3492..f4d38546068f 100644
--- a/drivers/mtd/nftlcore.c
+++ b/drivers/mtd/nftlcore.c
@@ -147,10 +147,9 @@ int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
         ops.ooblen = len;
         ops.oobbuf = buf;
         ops.datbuf = NULL;
-        ops.len = len;
 
         res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
-        *retlen = ops.retlen;
+        *retlen = ops.oobretlen;
         return res;
 }
 
@@ -168,10 +167,9 @@ int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
         ops.ooblen = len;
         ops.oobbuf = buf;
         ops.datbuf = NULL;
-        ops.len = len;
 
         res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
-        *retlen = ops.retlen;
+        *retlen = ops.oobretlen;
         return res;
 }