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. Use SPI_NOR_NO_MULTI_PASS_PP to set MTD_NO_MULTI_PASS_WRITE, telling upper layers to avoid multi-pass page programming. In addition, update mtd->writesize to match the page size to make sure upper layers make the changes they need in one single go. Signed-off-by: Pratyush Yadav <[email protected]> --- drivers/mtd/spi-nor/core.c | 5 +++++ drivers/mtd/spi-nor/core.h | 6 ++++++ drivers/mtd/spi-nor/spansion.c | 2 +- 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index ff592468cc15..16d4bcfe7b10 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -3469,6 +3469,11 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, nor->page_size = nor->params->page_size; mtd->writebufsize = nor->page_size; + if (info->flags & SPI_NOR_NO_MULTI_PASS_PP) { + mtd->flags |= MTD_NO_MULTI_PASS_WRITE; + mtd->writesize = nor->page_size; + } + if (of_property_read_bool(np, "broken-flash-reset")) nor->flags |= SNOR_F_BROKEN_RESET; diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 0a775a7b5606..3394b7474c08 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -329,6 +329,12 @@ struct flash_info { * available I/O mode via a * volatile bit. */ +#define SPI_NOR_NO_MULTI_PASS_PP BIT(22) /* + * Once a page is programmed it + * cannot be programmed again + * without an erase operation in + * between. + */ /* Part specific fixup hooks. */ const struct spi_nor_fixups *fixups; diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c index 2c5c0f69dc5c..72430cd4e6af 100644 --- a/drivers/mtd/spi-nor/spansion.c +++ b/drivers/mtd/spi-nor/spansion.c @@ -275,7 +275,7 @@ static const struct flash_info spansion_parts[] = { SPI_NOR_NO_ERASE) }, { "s28hs512t", INFO(0x345b1a, 0, 256 * 1024, 256, SECT_4K | SPI_NOR_OCTAL_DTR_READ | - SPI_NOR_OCTAL_DTR_PP) + SPI_NOR_OCTAL_DTR_PP | SPI_NOR_NO_MULTI_PASS_PP) .fixups = &s28hs512t_fixups, }, }; -- 2.28.0
