| Message ID | 20220420134740.193563-1-tudor.ambarus@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] ARM: configs: at91: Remove MTD_BLOCK and use MTD_UBI_BLOCK for read only block FS | expand |
On 20/04/2022 at 15:47, Tudor Ambarus wrote: > Using mtdblock on raw flashes is generally a bad idea as it lacks > wear-leveling, bad block handling or power-cut management. > What happens when you use mtdblock and you change any sector of your > mtdblockX device, is that it reads the whole corresponding eraseblock into > the memory, erases the eraseblock, changes the sector in RAM, and writes > the whole eraseblock back. If you have a power failure when the eraseblock > is being erased, you lose all the block device sectors in it. The flash > will likely decay soon because the eraseblocks will wear out. > > Remove this archaic tool as its use case should rather be only for debug > purposes. This means that write-capable block file systems like ext2, > ext3, FAT, etc. will no longer be addressed with at91 defconfigs. For > read only block filesystems like SquashFS, use MTD_UBI_BLOCK instead and > benefit of UBI's bit-flip handling and wear-levelling. > > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> For the whole series: Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> and queued in at91-defconfig for 5.19. Best regards, Nicolas > --- > arch/arm/configs/at91_dt_defconfig | 2 +- > arch/arm/configs/sama5_defconfig | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/configs/at91_dt_defconfig b/arch/arm/configs/at91_dt_defconfig > index 549d01be0b47..cf79510631ea 100644 > --- a/arch/arm/configs/at91_dt_defconfig > +++ b/arch/arm/configs/at91_dt_defconfig > @@ -50,13 +50,13 @@ CONFIG_DEVTMPFS_MOUNT=y > CONFIG_MTD=y > CONFIG_MTD_TESTS=m > CONFIG_MTD_CMDLINE_PARTS=y > -CONFIG_MTD_BLOCK=y > CONFIG_MTD_DATAFLASH=y > CONFIG_MTD_RAW_NAND=y > CONFIG_MTD_NAND_ATMEL=y > CONFIG_MTD_SPI_NOR=y > CONFIG_MTD_UBI=y > CONFIG_MTD_UBI_FASTMAP=y > +CONFIG_MTD_UBI_BLOCK=y > CONFIG_BLK_DEV_LOOP=y > CONFIG_BLK_DEV_RAM=y > CONFIG_BLK_DEV_RAM_COUNT=4 > diff --git a/arch/arm/configs/sama5_defconfig b/arch/arm/configs/sama5_defconfig > index 03dd80c2a19e..1c4c5a035518 100644 > --- a/arch/arm/configs/sama5_defconfig > +++ b/arch/arm/configs/sama5_defconfig > @@ -57,13 +57,13 @@ CONFIG_DEVTMPFS_MOUNT=y > CONFIG_MTD=y > CONFIG_MTD_TESTS=m > CONFIG_MTD_CMDLINE_PARTS=y > -CONFIG_MTD_BLOCK=y > CONFIG_MTD_CFI=y > CONFIG_MTD_RAW_NAND=y > CONFIG_MTD_NAND_ATMEL=y > CONFIG_MTD_SPI_NOR=y > CONFIG_MTD_UBI=y > CONFIG_MTD_UBI_FASTMAP=y > +CONFIG_MTD_UBI_BLOCK=y > CONFIG_BLK_DEV_LOOP=y > CONFIG_BLK_DEV_RAM=y > CONFIG_BLK_DEV_RAM_COUNT=4
diff --git a/arch/arm/configs/at91_dt_defconfig b/arch/arm/configs/at91_dt_defconfig index 549d01be0b47..cf79510631ea 100644 --- a/arch/arm/configs/at91_dt_defconfig +++ b/arch/arm/configs/at91_dt_defconfig @@ -50,13 +50,13 @@ CONFIG_DEVTMPFS_MOUNT=y CONFIG_MTD=y CONFIG_MTD_TESTS=m CONFIG_MTD_CMDLINE_PARTS=y -CONFIG_MTD_BLOCK=y CONFIG_MTD_DATAFLASH=y CONFIG_MTD_RAW_NAND=y CONFIG_MTD_NAND_ATMEL=y CONFIG_MTD_SPI_NOR=y CONFIG_MTD_UBI=y CONFIG_MTD_UBI_FASTMAP=y +CONFIG_MTD_UBI_BLOCK=y CONFIG_BLK_DEV_LOOP=y CONFIG_BLK_DEV_RAM=y CONFIG_BLK_DEV_RAM_COUNT=4 diff --git a/arch/arm/configs/sama5_defconfig b/arch/arm/configs/sama5_defconfig index 03dd80c2a19e..1c4c5a035518 100644 --- a/arch/arm/configs/sama5_defconfig +++ b/arch/arm/configs/sama5_defconfig @@ -57,13 +57,13 @@ CONFIG_DEVTMPFS_MOUNT=y CONFIG_MTD=y CONFIG_MTD_TESTS=m CONFIG_MTD_CMDLINE_PARTS=y -CONFIG_MTD_BLOCK=y CONFIG_MTD_CFI=y CONFIG_MTD_RAW_NAND=y CONFIG_MTD_NAND_ATMEL=y CONFIG_MTD_SPI_NOR=y CONFIG_MTD_UBI=y CONFIG_MTD_UBI_FASTMAP=y +CONFIG_MTD_UBI_BLOCK=y CONFIG_BLK_DEV_LOOP=y CONFIG_BLK_DEV_RAM=y CONFIG_BLK_DEV_RAM_COUNT=4
Using mtdblock on raw flashes is generally a bad idea as it lacks wear-leveling, bad block handling or power-cut management. What happens when you use mtdblock and you change any sector of your mtdblockX device, is that it reads the whole corresponding eraseblock into the memory, erases the eraseblock, changes the sector in RAM, and writes the whole eraseblock back. If you have a power failure when the eraseblock is being erased, you lose all the block device sectors in it. The flash will likely decay soon because the eraseblocks will wear out. Remove this archaic tool as its use case should rather be only for debug purposes. This means that write-capable block file systems like ext2, ext3, FAT, etc. will no longer be addressed with at91 defconfigs. For read only block filesystems like SquashFS, use MTD_UBI_BLOCK instead and benefit of UBI's bit-flip handling and wear-levelling. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> --- arch/arm/configs/at91_dt_defconfig | 2 +- arch/arm/configs/sama5_defconfig | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)