[MTD] [OneNAND] Check the ECC status first instead of controller

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=83973b87938a06a2af7e2a7fd1b630c35f8baff4
Commit:     83973b87938a06a2af7e2a7fd1b630c35f8baff4
Parent:     271c5c59e00302494ffc299741e7fa2d63103e76
Author:     Kyungmin Park <kyungmin.park at samsung.com>
AuthorDate: Thu May 29 14:52:40 2008 +0900
Committer:  David Woodhouse <dwmw2 at infradead.org>
CommitDate: Wed Jun 4 17:45:39 2008 +0100

    [MTD] [OneNAND] Check the ECC status first instead of controller
    
    To get the correct information in case of power off recovery,
    it should read ECC status first
    Also remove previous workaround method.
    
    Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
    Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
---
 drivers/mtd/onenand/onenand_base.c |   54 ++++++++++++++++-------------------
 1 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 5d7965f..926cf3a 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -325,28 +325,11 @@ static int onenand_wait(struct mtd_info *mtd, int state)
 
 	ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);
 
-	if (ctrl & ONENAND_CTRL_ERROR) {
-		printk(KERN_ERR "onenand_wait: controller error = 0x%04x\n", ctrl);
-		if (ctrl & ONENAND_CTRL_LOCK)
-			printk(KERN_ERR "onenand_wait: it's locked error.\n");
-		if (state == FL_READING) {
-			/*
-			 * A power loss while writing can result in a page
-			 * becoming unreadable.  When the device is mounted
-			 * again, reading that page gives controller errors.
-			 * Upper level software like JFFS2 treat -EIO as fatal,
-			 * refusing to mount at all.  That means it is necessary
-			 * to treat the error as an ECC error to allow recovery.
-			 * Note that typically in this case, the eraseblock can
-			 * still be erased and rewritten i.e. it has not become
-			 * a bad block.
-			 */
-			mtd->ecc_stats.failed++;
-			return -EBADMSG;
-		}
-		return -EIO;
-	}
-
+	/*
+	 * In the Spec. it checks the controller status first
+	 * However if you get the correct information in case of
+	 * power off recovery (POR) test, it should read ECC status first
+	 */
 	if (interrupt & ONENAND_INT_READ) {
 		int ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
 		if (ecc) {
@@ -364,6 +347,15 @@ static int onenand_wait(struct mtd_info *mtd, int state)
 		return -EIO;
 	}
 
+	/* If there's controller error, it's a real error */
+	if (ctrl & ONENAND_CTRL_ERROR) {
+		printk(KERN_ERR "onenand_wait: controller error = 0x%04x\n",
+			ctrl);
+		if (ctrl & ONENAND_CTRL_LOCK)
+			printk(KERN_ERR "onenand_wait: it's locked error.\n");
+		return -EIO;
+	}
+
 	return 0;
 }
 
@@ -1135,22 +1127,26 @@ static int onenand_bbt_wait(struct mtd_info *mtd, int state)
 	interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
 	ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);
 
-	/* Initial bad block case: 0x2400 or 0x0400 */
-	if (ctrl & ONENAND_CTRL_ERROR) {
-		printk(KERN_DEBUG "onenand_bbt_wait: controller error = 0x%04x\n", ctrl);
-		return ONENAND_BBT_READ_ERROR;
-	}
-
 	if (interrupt & ONENAND_INT_READ) {
 		int ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
-		if (ecc & ONENAND_ECC_2BIT_ALL)
+		if (ecc & ONENAND_ECC_2BIT_ALL) {
+			printk(KERN_INFO "onenand_bbt_wait: ecc error = 0x%04x"
+				", controller error 0x%04x\n", ecc, ctrl);
 			return ONENAND_BBT_READ_ERROR;
+		}
 	} else {
 		printk(KERN_ERR "onenand_bbt_wait: read timeout!"
 			"ctrl=0x%04x intr=0x%04x\n", ctrl, interrupt);
 		return ONENAND_BBT_READ_FATAL_ERROR;
 	}
 
+	/* Initial bad block case: 0x2400 or 0x0400 */
+	if (ctrl & ONENAND_CTRL_ERROR) {
+		printk(KERN_DEBUG "onenand_bbt_wait: "
+			"controller error = 0x%04x\n", ctrl);
+		return ONENAND_BBT_READ_ERROR;
+	}
+
 	return 0;
 }