Messages in this thread | | | From | Pratyush Yadav <> | Subject | [PATCH 0/3] mtd: Make sure UBIFS does not do multi-pass page programming on flashes that don't support it | Date | Mon, 12 Oct 2020 23:34:01 +0530 |
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Hi,
The Cypress Semper S28 flash family uses 2-bit ECC by default. Under this ECC scheme, multi-pass page programs result in a program error. This means that unlike many other SPI NOR flashes, bit-walking cannot be done. In other words, once a page is programmed, its bits cannot then be flipped to 0 without an erase in between.
This causes problems with UBIFS because it uses bit-walking to clear EC and VID magic numbers from a PEB before issuing an erase to preserve the file system correctness in case of power cuts.
This series fixes that problem by introducing a flag MTD_NO_MULTI_PASS_WRITE that tells the file system layer that it can't do multi-pass writes. It also sets the writesize to the page size for such flashes to make sure file systems know that they should write the entire page in one go.
It is based on the xSPI/8D series that adds support for Cypress S28 flash [0]. The patches themselves are independent of that series in the sense that they don't rely on 8D support. But since S28 flash is not supported without that series, these patches don't make much sense without it.
Tested on Cypress S28HS512T and MT35XU512ABA on J7200 and J721E respectively.
[0] https://lore.kernel.org/linux-mtd/20201005153138.6437-1-p.yadav@ti.com/
Pratyush Yadav (3): mtd: abi: Introduce MTD_NO_MULTI_PASS_WRITE UBI: Do not zero out EC and VID when multi-pass writes are not supported mtd: spi-nor: core: Introduce SPI_NOR_NO_MULTI_PASS_PP
drivers/mtd/spi-nor/core.c | 5 +++++ drivers/mtd/spi-nor/core.h | 6 ++++++ drivers/mtd/spi-nor/spansion.c | 2 +- drivers/mtd/ubi/io.c | 2 +- include/uapi/mtd/mtd-abi.h | 1 + 5 files changed, 14 insertions(+), 2 deletions(-)
-- 2.28.0
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