mtd: nand: teach write_page and write_page_raw return an error code

There is an implemention of hardware ECC write page function which may return an
error indication.
For instance, using Atmel HW PMECC to write one page into a nand flash, the hardware
engine will compute the BCH ecc code for this page. so we need read a the
status register to theck whether the ecc code is generated.
But we cannot assume the status register always can be ready, for example,
incorrect hardware configuration or hardware issue, in such case we need
write_page() to return a error code.

Since the definition of 'write_page' function in struct nand_ecc_ctrl is 'void'.
So this patch will:
  1. add return 'int' value for 'write_page' function.
  2. to be consitent, add return 'int' value for 'write_page_raw' fuctions too.
  3. add code to test the return value, and if negative, indicate an
  error happend when write page with ECC.
  4. fix the compile warning in all impacted nand flash driver.

Note: I couldn't compile-test all of these easily, as some had ARCH dependencies.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 19 insertions, 8 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 0a8724e..98ba46e 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1911,12 +1911,14 @@ out:
  *
  * Not for syndrome calculating ECC controllers, which use a special oob layout.
  */
-static void nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 				const uint8_t *buf, int oob_required)
 {
 	chip->write_buf(mtd, buf, mtd->writesize);
 	if (oob_required)
 		chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+	return 0;
 }
 
 /**
@@ -1928,7 +1930,7 @@ static void nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
  *
  * We need a special oob layout and handling even when ECC isn't checked.
  */
-static void nand_write_page_raw_syndrome(struct mtd_info *mtd,
+static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
 					struct nand_chip *chip,
 					const uint8_t *buf, int oob_required)
 {
@@ -1958,6 +1960,8 @@ static void nand_write_page_raw_syndrome(struct mtd_info *mtd,
 	size = mtd->oobsize - (oob - chip->oob_poi);
 	if (size)
 		chip->write_buf(mtd, oob, size);
+
+	return 0;
 }
 /**
  * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
@@ -1966,7 +1970,7 @@ static void nand_write_page_raw_syndrome(struct mtd_info *mtd,
  * @buf: data buffer
  * @oob_required: must write chip->oob_poi to OOB
  */
-static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
+static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
 				  const uint8_t *buf, int oob_required)
 {
 	int i, eccsize = chip->ecc.size;
@@ -1983,7 +1987,7 @@ static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
 	for (i = 0; i < chip->ecc.total; i++)
 		chip->oob_poi[eccpos[i]] = ecc_calc[i];
 
-	chip->ecc.write_page_raw(mtd, chip, buf, 1);
+	return chip->ecc.write_page_raw(mtd, chip, buf, 1);
 }
 
 /**
@@ -1993,7 +1997,7 @@ static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
  * @buf: data buffer
  * @oob_required: must write chip->oob_poi to OOB
  */
-static void nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
 				  const uint8_t *buf, int oob_required)
 {
 	int i, eccsize = chip->ecc.size;
@@ -2013,6 +2017,8 @@ static void nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
 		chip->oob_poi[eccpos[i]] = ecc_calc[i];
 
 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+	return 0;
 }
 
 /**
@@ -2025,7 +2031,7 @@ static void nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
  * The hw generator calculates the error syndrome automatically. Therefore we
  * need a special oob layout and handling.
  */
-static void nand_write_page_syndrome(struct mtd_info *mtd,
+static int nand_write_page_syndrome(struct mtd_info *mtd,
 				    struct nand_chip *chip,
 				    const uint8_t *buf, int oob_required)
 {
@@ -2059,6 +2065,8 @@ static void nand_write_page_syndrome(struct mtd_info *mtd,
 	i = mtd->oobsize - (oob - chip->oob_poi);
 	if (i)
 		chip->write_buf(mtd, oob, i);
+
+	return 0;
 }
 
 /**
@@ -2080,9 +2088,12 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
 
 	if (unlikely(raw))
-		chip->ecc.write_page_raw(mtd, chip, buf, oob_required);
+		status = chip->ecc.write_page_raw(mtd, chip, buf, oob_required);
 	else
-		chip->ecc.write_page(mtd, chip, buf, oob_required);
+		status = chip->ecc.write_page(mtd, chip, buf, oob_required);
+
+	if (status < 0)
+		return status;
 
 	/*
 	 * Cached progamming disabled for now. Not sure if it's worth the