[MTD] OneNAND: Select correct chip's bufferRAM for DDP

OneNAND double-density package (DDP) has two chips, each with
their own bufferRAM.  The driver will skip loading data from
the NAND core if the data can be found in a bufferRAM, however
in that case, the correct chip's bufferRAM must be selected
before reading from bufferRAM.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

1 files changed, 16 insertions, 8 deletions

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index f690c1916d1d..779327b845d1 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -577,7 +577,7 @@ static int onenand_write_bufferram(struct mtd_info *mtd, int area,
 static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)
 {
         struct onenand_chip *this = mtd->priv;
-        int blockpage;
+        int blockpage, found = 0;
         unsigned int i;
 
         blockpage = (int) (addr >> this->page_shift);
@@ -585,16 +585,24 @@ static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)
         /* Is there valid data? */
         i = ONENAND_CURRENT_BUFFERRAM(this);
         if (this->bufferram[i].blockpage == blockpage)
-                return 1;
+                found = 1;
+        else {
+                /* Check another BufferRAM */
+                i = ONENAND_NEXT_BUFFERRAM(this);
+                if (this->bufferram[i].blockpage == blockpage) {
+                        ONENAND_SET_NEXT_BUFFERRAM(this);
+                        found = 1;
+                }
+        }
 
-        /* Check another BufferRAM */
-        i = ONENAND_NEXT_BUFFERRAM(this);
-        if (this->bufferram[i].blockpage == blockpage) {
-                ONENAND_SET_NEXT_BUFFERRAM(this);
-                return 1;
+        if (found && ONENAND_IS_DDP(this)) {
+                /* Select DataRAM for DDP */
+                int block = (int) (addr >> this->erase_shift);
+                int value = onenand_bufferram_address(this, block);
+                this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
         }
 
-        return 0;
+        return found;
 }
 
 /**