mtd: spinand: Fix incorrect parameters for on-die ECC

From: Frieder Schrempf <[email protected]>

The new generic NAND ECC framework stores the configuration and requirements in separate places since commit 93ef92f6f422 (" mtd: nand: Use the new generic ECC object "). In 5.10.x The SPI NAND layer still uses only the requirements to track the ECC properties. This mismatch leads to values of zero being used for ECC strength and step_size in the SPI NAND layer wherever nanddev_get_ecc_conf() is used and therefore breaks the SPI NAND on-die ECC support in 5.10.x.

By using nanddev_get_ecc_requirements() instead of nanddev_get_ecc_conf() for SPI NAND, we make sure that the correct parameters for the detected chip are used. In later versions (5.11.x) this is fixed anyway with the implementation of the SPI NAND on-die ECC engine.

Cc [email protected] # 5.10.x

Reported-by voice INTER connect GmbH <[email protected]>

Signed-off-by Frieder Schrempf <[email protected]>

---
Resending this with an improved subject prefix and because the previous mail wasn't delivered to some of the lists.

---
 drivers/mtd/nand/spi/core.c     | 6 +++---
 drivers/mtd/nand/spi/macronix.c | 6 +++---
 drivers/mtd/nand/spi/toshiba.c  | 6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

drivers/mtd/nand/spi/core.c +0 -0

index 558d8a14810b..8794a1f6eacd 100644
@@ -419,7 +419,7 @@ static int spinand_check_ecc_status(struct
 spinand_device *spinand, u8 status)
 		 * fixed, so let's return the maximum possible value

so that

drivers/mtd/nand/spi/core.c +3 -3

 		 * wear-leveling layers move the data immediately.
 		 */
-		return nanddev_get_ecc_conf(nand)->strength;
+		return nanddev_get_ecc_requirements(nand)->strength;
 
 	case STATUS_ECC_UNCOR_ERROR:
 		return -EBADMSG;

@@ -1090,8 +1090,8 @@ static int spinand_init(struct spinand_device
 *spinand) mtd->oobavail = ret;
 
 	/* Propagate ECC information to mtd_info */
-	mtd->ecc_strength = nanddev_get_ecc_conf(nand)->strength;
-	mtd->ecc_step_size = nanddev_get_ecc_conf(nand)->step_size;
+	mtd->ecc_strength =
 nanddev_get_ecc_requirements(nand)->strength;
+	mtd->ecc_step_size =
 nanddev_get_ecc_requirements(nand)->step_size; 
 	return 0;

(quoted diff) +0 -0

b/drivers/mtd/nand/spi/macronix.c index 8e801e4c3a00..cd7a9cacc3fb 100644 --- a/drivers/mtd/nand/spi/macronix.c
+++ b/drivers/mtd/nand/spi/macronix.c

drivers/mtd/nand/spi/macronix.c +1 -2

@@ -84,11 +84,11 @@ static int mx35lf1ge4ab_ecc_get_status(struct
 spinand_device *spinand,
 		 * data around if it's not necessary.
 		 */
 		if (mx35lf1ge4ab_get_eccsr(spinand, &eccsr))
-			return nanddev_get_ecc_conf(nand)->strength;
+			return
 nanddev_get_ecc_requirements(nand)->strength; 
-		if (WARN_ON(eccsr >

nanddev_get_ecc_conf(nand)->strength ||

(quoted diff) +1 -0

+		if (WARN_ON(eccsr >

nanddev_get_ecc_requirements(nand)->strength || !eccsr))

(quoted diff) +1 -1

-			return nanddev_get_ecc_conf(nand)->strength;
+			return

nanddev_get_ecc_requirements(nand)->strength;

drivers/mtd/nand/spi/macronix.c +0 -0

 		return eccsr;

(quoted diff) +0 -0

b/drivers/mtd/nand/spi/toshiba.c index 21fde2875674..6fe7bd2a94d2 100644 --- a/drivers/mtd/nand/spi/toshiba.c
+++ b/drivers/mtd/nand/spi/toshiba.c

(quoted diff) +3 -3

@@ -90,12 +90,12 @@ static int tx58cxgxsxraix_ecc_get_status(struct
 spinand_device *spinand,
 		 * data around if it's not necessary.
 		 */
 		if (spi_mem_exec_op(spinand->spimem, &op))
-			return nanddev_get_ecc_conf(nand)->strength;
+			return
 nanddev_get_ecc_requirements(nand)->strength; 
 		mbf >>= 4;
 
-		if (WARN_ON(mbf >
 nanddev_get_ecc_conf(nand)->strength || !mbf))
-			return nanddev_get_ecc_conf(nand)->strength;
+		if (WARN_ON(mbf >
 nanddev_get_ecc_requirements(nand)->strength || !mbf))
+			return

nanddev_get_ecc_requirements(nand)->strength;
return mbf;

Hi Frieder,

Frieder Schrempf <[email protected]> wrote on Mon, 30 Aug 2021 09:21:07 +0200:

Quoted 9 lines

From: Frieder Schrempf <[email protected]>

The new generic NAND ECC framework stores the configuration and requirements in separate places since commit 93ef92f6f422 (" mtd: nand: Use the new generic ECC object "). In 5.10.x The SPI NAND layer still uses only the requirements to track the ECC properties. This mismatch leads to values of zero being used for ECC strength and step_size in the SPI NAND layer wherever nanddev_get_ecc_conf() is used and therefore breaks the SPI NAND on-die ECC support in 5.10.x.

Quoted 8 lines

By using nanddev_get_ecc_requirements() instead of nanddev_get_ecc_conf() for SPI NAND, we make sure that the correct parameters for the detected chip are used. In later versions (5.11.x) this is fixed anyway with the implementation of the SPI NAND on-die ECC engine.

Cc [email protected] # 5.10.x

Reported-by voice INTER connect GmbH <[email protected]>

Signed-off-by Frieder Schrempf <[email protected]>

Why not just reverting 9a333a72c1d0 ("mtd: spinand: Use nanddev_get_ecc_conf() when relevant")? I think using this "new" nanddev_get_ecc_requirements() helper because it fits the purpose even if it is wrong [1] doesn't bring the right information. I know it is strictly equivalent but I would personally prefer keeping the old writing "nand->eccreq.xxxx".

[1] We don't want the requirements but the actual current configuration here, which was the primary purpose of the initial patch which ended being a mistake at that point in time because the SPI-NAND core was not ready yet.

Thanks,
Miquèl

Quoted 23 lines

Hi Frieder,

Frieder Schrempf <[email protected]> wrote on Mon, 30 Aug 2021 09:21:07 +0200:

Quoted 17 lines

From: Frieder Schrempf <[email protected]>

The new generic NAND ECC framework stores the configuration and requirements in separate places since commit 93ef92f6f422 (" mtd: nand: Use the new generic ECC object "). In 5.10.x The SPI NAND layer still uses only the requirements to track the ECC properties. This mismatch leads to values of zero being used for ECC strength and step_size in the SPI NAND layer wherever nanddev_get_ecc_conf() is used and therefore breaks the SPI NAND on-die ECC support in 5.10.x.

By using nanddev_get_ecc_requirements() instead of nanddev_get_ecc_conf() for SPI NAND, we make sure that the correct parameters for the detected chip are used. In later versions (5.11.x) this is fixed anyway with the implementation of the SPI NAND on-die ECC engine.

Cc [email protected] # 5.10.x

Reported-by voice INTER connect GmbH <[email protected]>

Signed-off-by Frieder Schrempf <[email protected]>

Quoted 6 lines

Why not just reverting 9a333a72c1d0 ("mtd: spinand: Use nanddev_get_ecc_conf() when relevant")? I think using this "new" nanddev_get_ecc_requirements() helper because it fits the purpose even if it is wrong [1] doesn't bring the right information. I know it is strictly equivalent but I would personally prefer keeping the old writing "nand->eccreq.xxxx".

I think reverting 9a333a72c1d0 to use nand->eccreq.xxxx doesn't work as the eccreq member has already been removed in 93ef92f6f422 ("mtd: nand: Use the new generic ECC object"). So we would need to revert this commit, too. That would work for the SPI NAND layer, but might have implications on RAW NAND as it already uses the new generic ECC object with 'ctx.conf' and 'requirements'. At least I can't tell how this would affect the RAW NAND layer.

Quoted 9 lines

[1] We don't want the requirements but the actual current configuration here, which was the primary purpose of the initial patch which ended being a mistake at that point in time because the SPI-NAND core was not ready yet.

Thanks,
Miquèl