KumiSystems/openwrtv3
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

kernel: add support for limiting 4K erase sector support based on flash chip size

Browse source 
Some targets need 4K sectors for small flash chips (e.g. some
routerboards, where the entire chip is just one "erase block"), whereas
on other devices 4K sectors lead to horrible flash erase/write
performance.

Set the default limit in the generic kernel configuration to 4 MiB to
ensure that all new platforms don't use 4K sectors for bigger flash
chips. On all existing targets use 16 MiB for now to avoid regressions.
They will be changed individually in follow-up commits.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2017-11-03 09:53:54 +01:00
parent 94491a1571
commit c08293893a
9 changed files with 64 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
target/linux/ar71xx/mikrotik/config-default
View file

@ -232,6 +232,7 @@ CONFIG_MTD_NAND_RB750=y
CONFIG_MTD_NAND_RB91X=y
# CONFIG_MTD_REDBOOT_PARTS is not set
CONFIG_MTD_SPI_NOR_USE_4K_SECTORS=y
CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT=16384
# CONFIG_MTD_SPLIT_EVA_FW is not set
# CONFIG_MTD_SPLIT_TPLINK_FW is not set
# CONFIG_MTD_TPLINK_PARTS is not set

1
target/linux/generic/config-4.9
View file

@ -2632,6 +2632,7 @@ CONFIG_MTD_ROOTFS_ROOT_DEV=y
# CONFIG_MTD_SPINAND_MT29F 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_SPLIT=y
# CONFIG_MTD_SPLIT_BRNIMAGE_FW is not set
# CONFIG_MTD_SPLIT_EVA_FW is not set

56
target/linux/generic/pending-4.9/470-mtd-spi-nor-support-limiting-4K-sectors-support-base.patch Normal file
View file

@ -0,0 +1,56 @@
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
@@ -29,6 +29,17 @@ 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.
+
config SPI_ATMEL_QUADSPI
tristate "Atmel Quad SPI Controller"
depends on ARCH_AT91 || (ARM && COMPILE_TEST)
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1642,10 +1642,12 @@ int spi_nor_scan(struct spi_nor *nor, co
#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
/* prefer "small sector" erase if possible */
- if (info->flags & SECT_4K) {
+ if ((info->flags & SECT_4K) && (mtd->size <=
+ CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT * 1024)) {
nor->erase_opcode = SPINOR_OP_BE_4K;
mtd->erasesize = 4096;
- } else if (info->flags & SECT_4K_PMC) {
+ } else if ((info->flags & SECT_4K_PMC) && (mtd->size <=
+ CONFIG_MTD_SPI_NOR_USE_4K_SECTORS_LIMIT * 1024)) {
nor->erase_opcode = SPINOR_OP_BE_4K_PMC;
mtd->erasesize = 4096;
} else

1
target/linux/layerscape/armv8_32b/config-4.9
View file

@ -841,6 +841,7 @@ CONFIG_MTD_NAND_DENALI_DT=y
CONFIG_MTD_NAND_ECC=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_SST25L=y
CONFIG_MTD_UBI=y
CONFIG_MTD_UBI_BEB_LIMIT=20

1
target/linux/layerscape/armv8_64b/config-4.9
View file

@ -824,6 +824,7 @@ CONFIG_MTD_NAND_ECC=y
CONFIG_MTD_NAND_FSL_IFC=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_SST25L=y
CONFIG_MUTEX_SPIN_ON_OWNER=y
CONFIG_MV_XOR_V2=y

1
target/linux/pistachio/config-4.9
View file

@ -216,6 +216,7 @@ CONFIG_MTD_SPI_NAND=y
CONFIG_MTD_SPI_NAND_DEVICES=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

1
target/linux/ramips/mt7620/config-4.9
View file

@ -141,6 +141,7 @@ CONFIG_MTD_NAND_MT7620=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_FIRMWARE=y
CONFIG_MTD_SPLIT_SEAMA_FW=y
CONFIG_MTD_SPLIT_TPLINK_FW=y

1
target/linux/ramips/rt305x/config-4.9
View file

@ -134,6 +134,7 @@ CONFIG_MTD_M25P80=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_FIRMWARE=y
CONFIG_MTD_SPLIT_SEAMA_FW=y
CONFIG_MTD_SPLIT_UIMAGE_FW=y

1
target/linux/ramips/rt3883/config-4.9
View file

@ -134,6 +134,7 @@ CONFIG_MTD_M25P80=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_FIRMWARE=y
CONFIG_MTD_SPLIT_SEAMA_FW=y
CONFIG_MTD_SPLIT_UIMAGE_FW=y