kernel: cut broken SPI_NOR 4K eraseblock LIMIT patch

Since 4e0c54bc5bc8 ("kernel: add support for kernel 5.4"),
the spi-nor limit 4k erasesize to spi-nor chips below a configured size
patch has not functioned as intended.

For uniform erasesize SPI-NOR devices, both
nor->erase_opcode & mtd->erasesize are used in erase operations.
These are set before, and not modified by, this
CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT patch.
Thus, an SPI-NOR device with CONFIG_MTD_SPI_NOR_USE_4K_SECTORS will
always use 4k erasesize (where the device supports it).

If this patch was fixed to function as intended, there would be
cases where devices change from a 4K to a 64K erasesize.

Signed-off-by: John Thomson <git@johnthomson.fastmail.com.au>

target/linux/generic/config-5.10

@@ -3671,7 +3671,6 @@ CONFIG_MTD_ROOTFS_ROOT_DEV=y
 # CONFIG_MTD_SPI_NAND is not set
 # CONFIG_MTD_SPI_NOR is not set
 # CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is not set
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=4096
 # CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE is not set
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_BCM63XX_FW is not set

target/linux/generic/config-5.15

@@ -3814,7 +3814,6 @@ CONFIG_MTD_ROOTFS_ROOT_DEV=y
 CONFIG_MTD_SPI_NOR_SWP_DISABLE_ON_VOLATILE=y
 # CONFIG_MTD_SPI_NOR_SWP_KEEP is not set
 # CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is not set
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=4096
 # CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE is not set
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_BCM63XX_FW is not set

target/linux/generic/pending-5.10/470-mtd-spi-nor-support-limiting-4K-sectors-support-base.patch

@@ -1,71 +0,0 @@
-From: Felix Fietkau <nbd@nbd.name>
-Date: Sat, 4 Nov 2017 07:40:23 +0100
-Subject: [PATCH] mtd: spi-nor: support limiting 4K sectors support based on
- flash size
-
-Some devices need 4K sectors to be able to deal with small flash chips.
-For instance, w25x05 is 64 KiB in size, and without 4K sectors, the
-entire chip is just one erase block.
-On bigger flash chip sizes, using 4K sectors can significantly slow down
-many operations, including using a writable filesystem. There are several
-platforms where it makes sense to use a single kernel on both kinds of
-devices.
-
-To support this properly, allow configuring an upper flash chip size
-limit for 4K sectors support.
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
-
---- a/drivers/mtd/spi-nor/Kconfig
-+++ b/drivers/mtd/spi-nor/Kconfig
-@@ -34,6 +34,17 @@ config MTD_SPI_NOR_USE_4K_SECTORS
- 	  Please note that some tools/drivers/filesystems may not work with
- 	  4096 B erase size (e.g. UBIFS requires 15 KiB as a minimum).
- 
-+config MTD_SPI_NOR_USE_4K_SECTORS_LIMIT
-+	int "Maximum flash chip size to use 4K sectors on (in KiB)"
-+	depends on MTD_SPI_NOR_USE_4K_SECTORS
-+	default "4096"
-+	help
-+	  There are many flash chips that support 4K sectors, but are so large
-+	  that using them significantly slows down writing large amounts of
-+	  data or using a writable filesystem.
-+	  Any flash chip larger than the size specified in this option will
-+	  not use 4K sectors.
-+
- source "drivers/mtd/spi-nor/controllers/Kconfig"
- 
- endif # MTD_SPI_NOR
---- a/drivers/mtd/spi-nor/core.c
-+++ b/drivers/mtd/spi-nor/core.c
-@@ -2801,6 +2801,21 @@ static void spi_nor_info_init_params(str
- 	 */
- 	erase_mask = 0;
- 	i = 0;
-+#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
-+	if ((info->flags & SECT_4K_PMC) && (params->size <=
-+		   CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT * 1024)) {
-+		erase_mask |= BIT(i);
-+		spi_nor_set_erase_type(&map->erase_type[i], 4096u,
-+				       SPINOR_OP_BE_4K_PMC);
-+		i++;
-+	} else if ((info->flags & SECT_4K) && (params->size <=
-+	    CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT * 1024)) {
-+		erase_mask |= BIT(i);
-+		spi_nor_set_erase_type(&map->erase_type[i], 4096u,
-+				       SPINOR_OP_BE_4K);
-+		i++;
-+	}
-+#else
- 	if (info->flags & SECT_4K_PMC) {
- 		erase_mask |= BIT(i);
- 		spi_nor_set_erase_type(&map->erase_type[i], 4096u,
-@@ -2812,6 +2827,7 @@ static void spi_nor_info_init_params(str
- 				       SPINOR_OP_BE_4K);
- 		i++;
- 	}
-+#endif
- 	erase_mask |= BIT(i);
- 	spi_nor_set_erase_type(&map->erase_type[i], info->sector_size,
- 			       SPINOR_OP_SE);

target/linux/generic/pending-5.15/470-mtd-spi-nor-support-limiting-4K-sectors-support-base.patch

@@ -1,71 +0,0 @@
-From: Felix Fietkau <nbd@nbd.name>
-Date: Sat, 4 Nov 2017 07:40:23 +0100
-Subject: [PATCH] mtd: spi-nor: support limiting 4K sectors support based on
- flash size
-
-Some devices need 4K sectors to be able to deal with small flash chips.
-For instance, w25x05 is 64 KiB in size, and without 4K sectors, the
-entire chip is just one erase block.
-On bigger flash chip sizes, using 4K sectors can significantly slow down
-many operations, including using a writable filesystem. There are several
-platforms where it makes sense to use a single kernel on both kinds of
-devices.
-
-To support this properly, allow configuring an upper flash chip size
-limit for 4K sectors support.
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
-
---- a/drivers/mtd/spi-nor/Kconfig
-+++ b/drivers/mtd/spi-nor/Kconfig
-@@ -78,6 +78,17 @@ config MTD_SPI_NOR_SWP_KEEP
- 
- endchoice
- 
-+config MTD_SPI_NOR_USE_4K_SECTORS_LIMIT
-+	int "Maximum flash chip size to use 4K sectors on (in KiB)"
-+	depends on MTD_SPI_NOR_USE_4K_SECTORS
-+	default "4096"
-+	help
-+	  There are many flash chips that support 4K sectors, but are so large
-+	  that using them significantly slows down writing large amounts of
-+	  data or using a writable filesystem.
-+	  Any flash chip larger than the size specified in this option will
-+	  not use 4K sectors.
-+
- source "drivers/mtd/spi-nor/controllers/Kconfig"
- 
- endif # MTD_SPI_NOR
---- a/drivers/mtd/spi-nor/core.c
-+++ b/drivers/mtd/spi-nor/core.c
-@@ -2640,6 +2640,21 @@ static void spi_nor_info_init_params(str
- 	 */
- 	erase_mask = 0;
- 	i = 0;
-+#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
-+	if ((info->flags & SECT_4K_PMC) && (params->size <=
-+		   CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT * 1024)) {
-+		erase_mask |= BIT(i);
-+		spi_nor_set_erase_type(&map->erase_type[i], 4096u,
-+				       SPINOR_OP_BE_4K_PMC);
-+		i++;
-+	} else if ((info->flags & SECT_4K) && (params->size <=
-+	    CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT * 1024)) {
-+		erase_mask |= BIT(i);
-+		spi_nor_set_erase_type(&map->erase_type[i], 4096u,
-+				       SPINOR_OP_BE_4K);
-+		i++;
-+	}
-+#else
- 	if (info->flags & SECT_4K_PMC) {
- 		erase_mask |= BIT(i);
- 		spi_nor_set_erase_type(&map->erase_type[i], 4096u,
-@@ -2651,6 +2666,7 @@ static void spi_nor_info_init_params(str
- 				       SPINOR_OP_BE_4K);
- 		i++;
- 	}
-+#endif
- 	erase_mask |= BIT(i);
- 	spi_nor_set_erase_type(&map->erase_type[i], info->sector_size,
- 			       SPINOR_OP_SE);

target/linux/layerscape/armv8_64b/config-5.10

@@ -511,7 +511,6 @@ CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_RAW_NAND=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
 CONFIG_MTD_SPLIT_FIRMWARE=y
 CONFIG_MTD_SPLIT_FIT_FW=y
 CONFIG_MTD_SST25L=y

target/linux/pistachio/config-5.10

@@ -178,7 +178,6 @@ CONFIG_MTD_NAND_CORE=y
 CONFIG_MTD_SPI_NAND=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
 CONFIG_MTD_UBI=y
 CONFIG_MTD_UBI_BEB_LIMIT=20
 CONFIG_MTD_UBI_BLOCK=y

target/linux/ramips/mt7620/config-5.10

@@ -116,7 +116,6 @@ CONFIG_MTD_CMDLINE_PARTS=y
 CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
 CONFIG_MTD_SPLIT_JIMAGE_FW=y
 CONFIG_MTD_SPLIT_SEAMA_FW=y
 CONFIG_MTD_SPLIT_TPLINK_FW=y

target/linux/ramips/rt305x/config-5.10

@@ -106,7 +106,6 @@ CONFIG_MTD_CMDLINE_PARTS=y
 CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
 CONFIG_MTD_SPLIT_JIMAGE_FW=y
 CONFIG_MTD_SPLIT_SEAMA_FW=y
 CONFIG_MTD_SPLIT_UIMAGE_FW=y

target/linux/ramips/rt3883/config-5.10

@@ -104,7 +104,6 @@ CONFIG_MTD_CMDLINE_PARTS=y
 CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
-CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
 CONFIG_MTD_SPLIT_SEAMA_FW=y
 CONFIG_MTD_SPLIT_UIMAGE_FW=y
 CONFIG_NEED_DMA_MAP_STATE=y