[PATCH v7 0/3] mtd: spi-nand: Add support for randomizer feature

[PATCH v7 0/3] mtd: spi-nand: Add support for randomizer feature

[Cheng Ming Lin]

From: Cheng Ming Lin <chengminglin@mxic.com.tw>

This patch series introduces randomizer support for SPI NAND devices.

- Patch 1: add the nand-randomizer-enable and nand-randomizer-disable
           boolean properties to the generic nand-chip.yaml bindings.
- Patch 2: add the initialization logic and the set_randomizer callback
           to the core framework. The core will now parse the device tree
           properties and enable or disable the randomizer accordingly
           during spinand_init.
- Patch 3: implement the set_randomizer callback specifically for Macronix
           chips (MX35LF/UF series) to handle the vendor-specific register
           operations.

v7:
* Directly return the result in macronix_set_randomizer()

v6:
* Added mutual-exclusive constraints using not with required for
  nand-randomizer-enable and nand-randomizer-disable properties based
  on Krzysztof's feedback.
* Simplified the return path in macronix_set_randomizer() to directly
  return ret; and dropped unrelated formatting changes.

v5:
* Promoted the randomizer configuration to use generic NAND properties
  (nand-randomizer-enable and nand-randomizer-disable) instead of
  vendor-specific bindings.
* Refactored the initialization architecture in core.c. The core framework
  is now responsible for parsing the device tree properties and deciding
  whether to enable or disable the randomizer.

v4:
* Fix a build error in spinand_randomizer_init() where a value was
  returned from a void function. (Reported by kernel test robot)
* Update the return type to int.

v3:
* Revert the device tree property to the vendor-specific
  "mxic,randomizer-enable" to strictly follow vendor-specific bindings.

* Update the 'set_randomizer' callback signature to accept a boolean
  'enable' argument, allowing the feature to be explicitly enabled or
  disabled.

* Switch the implementation to use the standard SET_FEATURE command
  to modify the Configuration Register (0x10), replacing the previous
  special program command method.

v2:
* Create a global NAND DT property

Cheng Ming Lin (3):
  dt-bindings: mtd: spinand: Add randomizer enable/disable properties
  mtd: spi-nand: Add support for randomizer
  mtd: spi-nand: macronix: Enable randomizer support

 .../devicetree/bindings/mtd/nand-chip.yaml    | 18 +++++++++
 drivers/mtd/nand/spi/core.c                   | 27 +++++++++++++
 drivers/mtd/nand/spi/macronix.c               | 38 ++++++++++++++-----
 include/linux/mtd/spinand.h                   |  9 +++++
 4 files changed, 82 insertions(+), 10 deletions(-)

-- 
2.25.1

[PATCH v7 1/3] dt-bindings: mtd: spinand: Add randomizer enable/disable properties

[Cheng Ming Lin]

From: Cheng Ming Lin <chengminglin@mxic.com.tw>

Add "nand-randomizer-enable" and "nand-randomizer-disable" boolean
properties.

These properties allow enabling or disabling the randomizer feature
via the device tree.

According to JEDEC standard JESD22-A117E, no single data pattern
represents a universal worst-case for all NAND flash failure mechanisms.
Different patterns, such as fully programmed, checkerboard, or mostly
erased, can disproportionately stress specific cells (e.g., programmed,
erased, or those influenced by adjacent states).

Given that no fixed pattern can cover all scenarios, the use of a
randomized data pattern is a practical and effective mitigation strategy.
Our hardware implements a randomizer feature that scrambles user data
before it is written to the flash and restores the original data upon read.

This ensures the data stored on the media is more evenly distributed,
thus reducing pattern-dependent degradation. This is especially crucial
for preventing errors caused by unbalanced data (e.g., all zeros or
all ones) in blocks with high program/erase (P/E) cycle counts.
Ultimately, the randomizer improves the long-term reliability and
endurance of the flash device.

Please refer to the following link for randomizer feature:
Link: https://www.mxic.com.tw/Lists/ApplicationNote/Attachments/2151/AN1051V1-The%20Introduction%20of%20Randomizer%20Feature%20on%20MX30xFxG28AD_MX35xFxG24AD.

Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>
---
 .../devicetree/bindings/mtd/nand-chip.yaml     | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/nand-chip.yaml b/Documentation/devicetree/bindings/mtd/nand-chip.yaml
index 609d4a4ddd80..2559cd97ccc5 100644
--- a/Documentation/devicetree/bindings/mtd/nand-chip.yaml
+++ b/Documentation/devicetree/bindings/mtd/nand-chip.yaml
@@ -67,6 +67,24 @@ properties:
       the secure regions present.
     $ref: /schemas/types.yaml#/definitions/uint64-matrix
 
+  nand-randomizer-enable:
+    description:
+      Enable the randomizer feature. This property is mutually-exclusive
+      with nand-randomizer-disable.
+    type: boolean
+
+  nand-randomizer-disable:
+    description:
+      Disable the randomizer feature. This property is mutually-exclusive
+      with nand-randomizer-enable.
+    type: boolean
+
+dependencies:
+  nand-randomizer-enable:
+    not:
+      required:
+        - nand-randomizer-disable
+
 required:
   - reg
 
-- 
2.25.1

[PATCH v7 2/3] mtd: spi-nand: Add support for randomizer

[Cheng Ming Lin]

From: Cheng Ming Lin <chengminglin@mxic.com.tw>

This patch adds support for the randomizer feature.

It introduces a 'set_randomizer' callback in 'struct spinand_info' and
'struct spinand_device'.

If a driver implements this callback, the core will invoke it during
device initialization (spinand_init) to enable or disable the randomizer
feature based on the device tree configuration.

Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>
---
 drivers/mtd/nand/spi/core.c | 27 +++++++++++++++++++++++++++
 include/linux/mtd/spinand.h |  9 +++++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 8aa3753aaaa1..77a0371010c4 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1307,6 +1307,29 @@ static int spinand_create_dirmaps(struct spinand_device *spinand)
 	return 0;
 }
 
+static int spinand_randomizer_init(struct spinand_device *spinand)
+{
+	struct device_node *np = spinand->spimem->spi->dev.of_node;
+	bool enable = false;
+	int ret;
+
+	if (!spinand->set_randomizer)
+		return 0;
+
+	if (of_property_read_bool(np, "nand-enable-randomizer"))
+		enable = true;
+	else if (of_property_read_bool(np, "nand-disable-randomizer"))
+		enable = false;
+	else
+		return 0;
+
+	ret = spinand->set_randomizer(spinand, enable);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static const struct nand_ops spinand_ops = {
 	.erase = spinand_erase,
 	.markbad = spinand_markbad,
@@ -1594,6 +1617,7 @@ int spinand_match_and_init(struct spinand_device *spinand,
 		spinand->user_otp = &table[i].user_otp;
 		spinand->read_retries = table[i].read_retries;
 		spinand->set_read_retry = table[i].set_read_retry;
+		spinand->set_randomizer = table[i].set_randomizer;
 
 		/* I/O variants selection with single-spi SDR commands */
 
@@ -1881,6 +1905,9 @@ static int spinand_init(struct spinand_device *spinand)
 	 * ECC initialization must have happened previously.
 	 */
 	spinand_cont_read_init(spinand);
+	ret = spinand_randomizer_init(spinand);
+	if (ret)
+		goto err_cleanup_nanddev;
 
 	mtd->_read_oob = spinand_mtd_read;
 	mtd->_write_oob = spinand_mtd_write;
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 6a024cf1c53a..6a68a6c3866a 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -584,6 +584,7 @@ enum spinand_bus_interface {
  * @user_otp: SPI NAND user OTP info.
  * @read_retries: the number of read retry modes supported
  * @set_read_retry: enable/disable read retry for data recovery
+ * @set_randomizer: enable/disable randomizer support
  *
  * Each SPI NAND manufacturer driver should have a spinand_info table
  * describing all the chips supported by the driver.
@@ -612,6 +613,8 @@ struct spinand_info {
 	unsigned int read_retries;
 	int (*set_read_retry)(struct spinand_device *spinand,
 			     unsigned int read_retry);
+	int (*set_randomizer)(struct spinand_device *spinand,
+			      bool enable);
 };
 
 #define SPINAND_ID(__method, ...)					\
@@ -668,6 +671,9 @@ struct spinand_info {
 	.read_retries = __read_retries,					\
 	.set_read_retry = __set_read_retry
 
+#define SPINAND_RANDOMIZER(__set_randomizer)				\
+	.set_randomizer = __set_randomizer
+
 #define SPINAND_INFO(__model, __id, __memorg, __eccreq, __op_variants,	\
 		     __flags, ...)					\
 	{								\
@@ -753,6 +759,7 @@ struct spinand_mem_ops {
  * @user_otp: SPI NAND user OTP info.
  * @read_retries: the number of read retry modes supported
  * @set_read_retry: Enable/disable the read retry feature
+ * @set_randomizer: Enable/disable the randomizer feature
  */
 struct spinand_device {
 	struct nand_device base;
@@ -786,6 +793,8 @@ struct spinand_device {
 	bool cont_read_possible;
 	int (*set_cont_read)(struct spinand_device *spinand,
 			     bool enable);
+	int (*set_randomizer)(struct spinand_device *spinand,
+			      bool enable);
 
 	const struct spinand_fact_otp *fact_otp;
 	const struct spinand_user_otp *user_otp;
-- 
2.25.1

[PATCH v7 3/3] mtd: spi-nand: macronix: Enable randomizer support

[Cheng Ming Lin]

From: Cheng Ming Lin <chengminglin@mxic.com.tw>

Implement the 'set_randomizer' callback for Macronix SPI NAND chips.
The randomizer is enabled by setting bit 1 of the Configuration Register
(address 0x10).

This patch adds support for the following chips:
  - MX35LFxG24AD series
  - MX35UFxG24AD series

When the randomizer is enabled, data is scrambled internally during
program operations and automatically descrambled during read operations.
This helps reduce bit errors caused by program disturbance.

Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>
---
 drivers/mtd/nand/spi/macronix.c | 38 ++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/nand/spi/macronix.c b/drivers/mtd/nand/spi/macronix.c
index 67cafa1bb8ef..7dfcc34e9b72 100644
--- a/drivers/mtd/nand/spi/macronix.c
+++ b/drivers/mtd/nand/spi/macronix.c
@@ -14,6 +14,8 @@
 #define MACRONIX_ECCSR_BF_LAST_PAGE(eccsr) FIELD_GET(GENMASK(3, 0), eccsr)
 #define MACRONIX_ECCSR_BF_ACCUMULATED_PAGES(eccsr) FIELD_GET(GENMASK(7, 4), eccsr)
 #define MACRONIX_CFG_CONT_READ         BIT(2)
+#define MACRONIX_CFG_RANDOMIZER_EN     BIT(1)
+#define MACRONIX_FEATURE_ADDR_RANDOMIZER 0x10
 #define MACRONIX_FEATURE_ADDR_READ_RETRY 0x70
 #define MACRONIX_NUM_READ_RETRY_MODES 5
 
@@ -170,6 +172,12 @@ static int macronix_set_read_retry(struct spinand_device *spinand,
 	return spi_mem_exec_op(spinand->spimem, &op);
 }
 
+static int macronix_set_randomizer(struct spinand_device *spinand, bool enable)
+{
+	return spinand_write_reg_op(spinand, MACRONIX_FEATURE_ADDR_RANDOMIZER,
+				    enable ? MACRONIX_CFG_RANDOMIZER_EN : 0);
+}
+
 static const struct spinand_info macronix_spinand_table[] = {
 	SPINAND_INFO("MX35LF1GE4AB",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x12),
@@ -231,7 +239,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_HAS_QE_BIT,
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout, NULL),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35LF2G24AD",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x24, 0x03),
 		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 2, 1, 1),
@@ -243,7 +252,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_HAS_PROG_PLANE_SELECT_BIT,
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout, NULL),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35LF2G24AD-Z4I8",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x64, 0x03),
 		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 1, 1, 1),
@@ -254,7 +264,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_HAS_QE_BIT,
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout, NULL),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35LF4G24AD",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x35, 0x03),
 		     NAND_MEMORG(1, 4096, 256, 64, 2048, 40, 2, 1, 1),
@@ -266,7 +277,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_HAS_PROG_PLANE_SELECT_BIT,
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout, NULL),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35LF4G24AD-Z4I8",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x75, 0x03),
 		     NAND_MEMORG(1, 4096, 256, 64, 2048, 40, 1, 1, 1),
@@ -277,7 +289,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_HAS_QE_BIT,
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout, NULL),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX31LF1GE4BC",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x1e),
 		     NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
@@ -327,7 +340,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout,
 				     macronix_ecc_get_status),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35UF4G24AD-Z4I8",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xf5, 0x03),
 		     NAND_MEMORG(1, 4096, 256, 64, 2048, 40, 1, 1, 1),
@@ -340,7 +354,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout,
 				     macronix_ecc_get_status),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35UF4GE4AD",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xb7, 0x03),
 		     NAND_MEMORG(1, 4096, 256, 64, 2048, 40, 1, 1, 1),
@@ -381,7 +396,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout,
 				     macronix_ecc_get_status),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35UF2G24AD-Z4I8",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xe4, 0x03),
 		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 1, 1, 1),
@@ -394,7 +410,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout,
 				     macronix_ecc_get_status),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35UF2GE4AD",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xa6, 0x03),
 		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 1, 1, 1),
@@ -444,7 +461,8 @@ static const struct spinand_info macronix_spinand_table[] = {
 		     SPINAND_ECCINFO(&mx35lfxge4ab_ooblayout,
 				     macronix_ecc_get_status),
 		     SPINAND_READ_RETRY(MACRONIX_NUM_READ_RETRY_MODES,
-					macronix_set_read_retry)),
+					macronix_set_read_retry),
+		     SPINAND_RANDOMIZER(macronix_set_randomizer)),
 	SPINAND_INFO("MX35UF1GE4AD",
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x96, 0x03),
 		     NAND_MEMORG(1, 2048, 128, 64, 1024, 20, 1, 1, 1),
-- 
2.25.1

Re: [PATCH v7 1/3] dt-bindings: mtd: spinand: Add randomizer enable/disable properties

[Miquel Raynal]

On 25/02/2026 at 09:57:03 +08, Cheng Ming Lin <linchengming884@gmail.com> wrote:

> From: Cheng Ming Lin <chengminglin@mxic.com.tw>
>
> Add "nand-randomizer-enable" and "nand-randomizer-disable" boolean
> properties.
>
> These properties allow enabling or disabling the randomizer feature
> via the device tree.
>
> According to JEDEC standard JESD22-A117E, no single data pattern
> represents a universal worst-case for all NAND flash failure mechanisms.
> Different patterns, such as fully programmed, checkerboard, or mostly
> erased, can disproportionately stress specific cells (e.g., programmed,
> erased, or those influenced by adjacent states).
>
> Given that no fixed pattern can cover all scenarios, the use of a
> randomized data pattern is a practical and effective mitigation strategy.
> Our hardware implements a randomizer feature that scrambles user data
> before it is written to the flash and restores the original data upon read.
>
> This ensures the data stored on the media is more evenly distributed,
> thus reducing pattern-dependent degradation. This is especially crucial
> for preventing errors caused by unbalanced data (e.g., all zeros or
> all ones) in blocks with high program/erase (P/E) cycle counts.
> Ultimately, the randomizer improves the long-term reliability and
> endurance of the flash device.
>
> Please refer to the following link for randomizer feature:
> Link:
> https://www.mxic.com.tw/Lists/ApplicationNote/Attachments/2151/AN1051V1-The%20Introduction%20of%20Randomizer%20Feature%20on%20MX30xFxG28AD_MX35xFxG24AD.

This link brings me to a "We have moved to our new home" page.

Anyhow, this Links does not make much sense in the binding. If this is a
very generic AN, why not, but maybe I'd move it to the SPI NAND patches,
as the name implies that it is a bit specific to Macronix chips.

> Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>

Otherwise both the binding and code look ok from my PoV. So besides the
Link that must be moved and fixed, I'll wait for binding approval.

Thanks,
Miquèl

Re: [PATCH v7 1/3] dt-bindings: mtd: spinand: Add randomizer enable/disable properties

[Miquel Raynal]

Hello Cheng Ming,

On 25/02/2026 at 09:57:03 +08, Cheng Ming Lin <linchengming884@gmail.com> wrote:

> From: Cheng Ming Lin <chengminglin@mxic.com.tw>
>
> Add "nand-randomizer-enable" and "nand-randomizer-disable" boolean
> properties.
>
> These properties allow enabling or disabling the randomizer feature
> via the device tree.
>
> According to JEDEC standard JESD22-A117E, no single data pattern
> represents a universal worst-case for all NAND flash failure mechanisms.
> Different patterns, such as fully programmed, checkerboard, or mostly
> erased, can disproportionately stress specific cells (e.g., programmed,
> erased, or those influenced by adjacent states).
>
> Given that no fixed pattern can cover all scenarios, the use of a
> randomized data pattern is a practical and effective mitigation strategy.
> Our hardware implements a randomizer feature that scrambles user data
> before it is written to the flash and restores the original data upon read.
>
> This ensures the data stored on the media is more evenly distributed,
> thus reducing pattern-dependent degradation. This is especially crucial
> for preventing errors caused by unbalanced data (e.g., all zeros or
> all ones) in blocks with high program/erase (P/E) cycle counts.
> Ultimately, the randomizer improves the long-term reliability and
> endurance of the flash device.
>
> Please refer to the following link for randomizer feature:
> Link:
> https://www.mxic.com.tw/Lists/ApplicationNote/Attachments/2151/AN1051V1-The%20Introduction%20of%20Randomizer%20Feature%20on%20MX30xFxG28AD_MX35xFxG24AD.

This link brings me to a "We have moved to our new home" page.

Anyhow, this Link does not make much sense in the binding. If this is a
very generic AN, why not, but maybe I'd move it to the SPI NAND patches,
as the name implies that it is a bit specific to Macronix chips.

> Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>

Otherwise both the binding and code look ok from my PoV. So besides the
Link that must be moved and fixed, I'll wait for binding approval.

Thanks,
Miquèl

Re: [PATCH v7 1/3] dt-bindings: mtd: spinand: Add randomizer enable/disable properties

[Cheng Ming Lin]

Hi Miquel,

Miquel Raynal <miquel.raynal@bootlin.com> 於 2026年2月25日週三 下午11:10寫道：
>
> Hello Cheng Ming,
>
> On 25/02/2026 at 09:57:03 +08, Cheng Ming Lin <linchengming884@gmail.com> wrote:
>
> > From: Cheng Ming Lin <chengminglin@mxic.com.tw>
> >
> > Add "nand-randomizer-enable" and "nand-randomizer-disable" boolean
> > properties.
> >
> > These properties allow enabling or disabling the randomizer feature
> > via the device tree.
> >
> > According to JEDEC standard JESD22-A117E, no single data pattern
> > represents a universal worst-case for all NAND flash failure mechanisms.
> > Different patterns, such as fully programmed, checkerboard, or mostly
> > erased, can disproportionately stress specific cells (e.g., programmed,
> > erased, or those influenced by adjacent states).
> >
> > Given that no fixed pattern can cover all scenarios, the use of a
> > randomized data pattern is a practical and effective mitigation strategy.
> > Our hardware implements a randomizer feature that scrambles user data
> > before it is written to the flash and restores the original data upon read.
> >
> > This ensures the data stored on the media is more evenly distributed,
> > thus reducing pattern-dependent degradation. This is especially crucial
> > for preventing errors caused by unbalanced data (e.g., all zeros or
> > all ones) in blocks with high program/erase (P/E) cycle counts.
> > Ultimately, the randomizer improves the long-term reliability and
> > endurance of the flash device.
> >
> > Please refer to the following link for randomizer feature:
> > Link:
> > https://www.mxic.com.tw/Lists/ApplicationNote/Attachments/2151/AN1051V1-The%20Introduction%20of%20Randomizer%20Feature%20on%20MX30xFxG28AD_MX35xFxG24AD.
>
> This link brings me to a "We have moved to our new home" page.

I apologize for the broken link. I will find the updated, active link
for the Application Note.

>
> Anyhow, this Link does not make much sense in the binding. If this is a
> very generic AN, why not, but maybe I'd move it to the SPI NAND patches,
> as the name implies that it is a bit specific to Macronix chips.

You are right about the placement. Since the randomizer feature and this
AN are indeed specific to Macronix chips, I agree it makes much more sense
in the driver patch. I will remove the link from the dt-binding commit
message and move the updated link to the SPI NAND patches in the next
version.

>
> > Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>
>
> Otherwise both the binding and code look ok from my PoV. So besides the
> Link that must be moved and fixed, I'll wait for binding approval.
>
> Thanks,
> Miquèl

Thanks,
Cheng Ming Lin