Messages in this thread | | | From | Pratyush Yadav <> | Subject | [PATCH v3 0/3] mtd: Make sure UBIFS does not do multi-pass page programming on flashes that don't support it | Date | Tue, 1 Dec 2020 15:57:08 +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 by setting mtd->writesize to the ECC block size (16) and making sure UBIFS does not try to do a multi-pass write on flashes with writesize > 1.
It is based on the xSPI/8D series that adds support for Cypress S28 flash [0] (it is in next now). 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): UBI: Do not zero out EC and VID on ECC-ed NOR flashes mtd: spi-nor: core: Allow flashes to specify MTD writesize mtd: spi-nor: spansion: Set ECC block size
drivers/mtd/spi-nor/core.c | 3 ++- drivers/mtd/spi-nor/core.h | 3 +++ drivers/mtd/spi-nor/spansion.c | 1 + drivers/mtd/ubi/build.c | 4 +--- drivers/mtd/ubi/io.c | 9 ++++++++- 5 files changed, 15 insertions(+), 5 deletions(-)
-- 2.28.0
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