diff mbox series

[v2,2/2] mtd: rawnand: brcmnand: ECC error handling on EDU transfers

Message ID 20200612212902.21347-3-kdasu.kdev@gmail.com
State Accepted
Headers show
Series mtd: rawnand: brcmnand: ECC error handling on EDU transfers | expand

Commit Message

Kamal Dasu June 12, 2020, 9:29 p.m. UTC
Implement ECC correctable and uncorrectable error handling for EDU
reads. If ECC correctable bitflips are encountered on EDU transfer,
read page again using PIO. This is needed due to a NAND controller
limitation where corrected data is not transferred to the DMA buffer
on ECC error. This applies to ECC correctable errors that are reported
by the controller hardware based on set number of bitflips threshold in
the controller threshold register, bitflips below the threshold are
corrected silently and are not reported by the controller hardware.

Fixes: a5d53ad26a8b ("mtd: rawnand: brcmnand: Add support for flash-edu for dma transfers")
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
 drivers/mtd/nand/raw/brcmnand/brcmnand.c | 26 ++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

Comments

Miquel Raynal June 15, 2020, 8:59 a.m. UTC | #1
On Fri, 2020-06-12 at 21:29:02 UTC, Kamal Dasu wrote:
> Implement ECC correctable and uncorrectable error handling for EDU
> reads. If ECC correctable bitflips are encountered on EDU transfer,
> read page again using PIO. This is needed due to a NAND controller
> limitation where corrected data is not transferred to the DMA buffer
> on ECC error. This applies to ECC correctable errors that are reported
> by the controller hardware based on set number of bitflips threshold in
> the controller threshold register, bitflips below the threshold are
> corrected silently and are not reported by the controller hardware.
> 
> Fixes: a5d53ad26a8b ("mtd: rawnand: brcmnand: Add support for flash-edu for dma transfers")
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel
diff mbox series

Patch

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index 0c1d6e543586..131d5d6e2626 100644
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1855,6 +1855,22 @@  static int brcmnand_edu_trans(struct brcmnand_host *host, u64 addr, u32 *buf,
 	edu_writel(ctrl, EDU_STOP, 0); /* force stop */
 	edu_readl(ctrl, EDU_STOP);
 
+	if (!ret && edu_cmd == EDU_CMD_READ) {
+		u64 err_addr = 0;
+
+		/*
+		 * check for ECC errors here, subpage ECC errors are
+		 * retained in ECC error address register
+		 */
+		err_addr = brcmnand_get_uncorrecc_addr(ctrl);
+		if (!err_addr) {
+			err_addr = brcmnand_get_correcc_addr(ctrl);
+			if (err_addr)
+				ret = -EUCLEAN;
+		} else
+			ret = -EBADMSG;
+	}
+
 	return ret;
 }
 
@@ -2058,6 +2074,7 @@  static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip,
 	u64 err_addr = 0;
 	int err;
 	bool retry = true;
+	bool edu_err = false;
 
 	dev_dbg(ctrl->dev, "read %llx -> %p\n", (unsigned long long)addr, buf);
 
@@ -2075,6 +2092,10 @@  static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip,
 			else
 				return -EIO;
 		}
+
+		if (has_edu(ctrl) && err_addr)
+			edu_err = true;
+
 	} else {
 		if (oob)
 			memset(oob, 0x99, mtd->oobsize);
@@ -2122,6 +2143,11 @@  static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip,
 	if (mtd_is_bitflip(err)) {
 		unsigned int corrected = brcmnand_count_corrected(ctrl);
 
+		/* in case of EDU correctable error we read again using PIO */
+		if (edu_err)
+			err = brcmnand_read_by_pio(mtd, chip, addr, trans, buf,
+						   oob, &err_addr);
+
 		dev_dbg(ctrl->dev, "corrected error at 0x%llx\n",
 			(unsigned long long)err_addr);
 		mtd->ecc_stats.corrected += corrected;