mtd: cfi: fix writebufsize initialization

When initializing mtd->writebufsize, we must take into account
possible flash chip interleaving. Wrong writebufsize initialization
caused UBIFS recovery issues resulting in unmountable UBIFS file
system on NOR flash partitions.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Guillaume LECERF <glecerf@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index f072fcf..7e9c4e9 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -440,7 +440,7 @@
 	mtd->flags   = MTD_CAP_NORFLASH;
 	mtd->name    = map->name;
 	mtd->writesize = 1;
-	mtd->writebufsize = 1 << cfi->cfiq->MaxBufWriteSize;
+	mtd->writebufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
 
 	DEBUG(MTD_DEBUG_LEVEL3, "MTD %s(): write buffer size %d\n",
 		__func__, mtd->writebufsize);