[MTD] OneNAND: Amend write-verify to compare to original buffer

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=8b29c0b6eb3a4952e7eae03038bbf6c1695dfe80
Commit:     8b29c0b6eb3a4952e7eae03038bbf6c1695dfe80
Parent:     ec255e34061bbc48fc702875336c6db969df9461
Author:     Adrian Hunter <ext-adrian.hunter at nokia.com>
AuthorDate: Thu Jan 25 14:06:33 2007 +0900
Committer:  Kyungmin Park <kyungmin.park at samsung.com>
CommitDate: Thu Jan 25 14:06:33 2007 +0900

    [MTD] OneNAND: Amend write-verify to compare to original buffer
    
    When write-verify is enabled (CONFIG_MTD_ONENAND_VERIFY_WRITE),
    the data written is read back and compared.  The comparison
    was being made between dataRAM buffers, but this does not
    verify that the data made it to the dataRAM correctly in
    the first place.  This patch amends write-verify to
    compare back to the original buffer.  It also now verifies
    sub-page writes.
    
    Signed-off-by: Adrian Hunter <ext-adrian.hunter at nokia.com>
    Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/mtd/onenand/onenand_base.c |   52 +++++++++++++++++++++--------------
 1 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 0249b4a..65acb85 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -909,41 +909,51 @@ static int onenand_verify_oob(struct mtd_info *mtd, const u_char *buf, loff_t to
 }
 
 /**
- * onenand_verify_page - [GENERIC] verify the chip contents after a write
- * @param mtd		MTD device structure
- * @param buf		the databuffer to verify
+ * onenand_verify - [GENERIC] verify the chip contents after a write
+ * @param mtd          MTD device structure
+ * @param buf          the databuffer to verify
+ * @param addr         offset to read from
+ * @param len          number of bytes to read and compare
  *
- * Check DataRAM area directly
  */
-static int onenand_verify_page(struct mtd_info *mtd, u_char *buf, loff_t addr)
+static int onenand_verify(struct mtd_info *mtd, const u_char *buf, loff_t addr, size_t len)
 {
 	struct onenand_chip *this = mtd->priv;
-	void __iomem *dataram0, *dataram1;
+	void __iomem *dataram;
 	int ret = 0;
+	int thislen, column;
 
-	/* In partial page write, just skip it */
-	if ((addr & (mtd->writesize - 1)) != 0)
-		return 0;
+	while (len != 0) {
+		thislen = min_t(int, mtd->writesize, len);
+		column = addr & (mtd->writesize - 1);
+		if (column + thislen > mtd->writesize)
+			thislen = mtd->writesize - column;
 
-	this->command(mtd, ONENAND_CMD_READ, addr, mtd->writesize);
+		this->command(mtd, ONENAND_CMD_READ, addr, mtd->writesize);
 
-	ret = this->wait(mtd, FL_READING);
-	if (ret)
-		return ret;
+		onenand_update_bufferram(mtd, addr, 0);
+
+		ret = this->wait(mtd, FL_READING);
+		if (ret)
+			return ret;
 
-	onenand_update_bufferram(mtd, addr, 1);
+		onenand_update_bufferram(mtd, addr, 1);
 
-	/* Check, if the two dataram areas are same */
-	dataram0 = this->base + ONENAND_DATARAM;
-	dataram1 = dataram0 + mtd->writesize;
+		dataram = this->base + ONENAND_DATARAM;
+		dataram += onenand_bufferram_offset(mtd, ONENAND_DATARAM);
 
-	if (memcmp(dataram0, dataram1, mtd->writesize))
-		return -EBADMSG;
+		if (memcmp(buf, dataram + column, thislen))
+			return -EBADMSG;
+
+		len -= thislen;
+		buf += thislen;
+		addr += thislen;
+	}
 
 	return 0;
 }
 #else
-#define onenand_verify_page(...)	(0)
+#define onenand_verify(...)		(0)
 #define onenand_verify_oob(...)		(0)
 #endif
 
@@ -1025,7 +1035,7 @@ static int onenand_write(struct mtd_info *mtd, loff_t to, size_t len,
 		}
 
 		/* Only check verify write turn on */
-		ret = onenand_verify_page(mtd, (u_char *) wbuf, to);
+		ret = onenand_verify(mtd, (u_char *) wbuf, to, thislen);
 		if (ret) {
 			DEBUG(MTD_DEBUG_LEVEL0, "onenand_write: verify failed %d\n", ret);
 			break;