[PATCH 2/2] mtd: spi-nor: Skip erase logic when SPI_NOR_NO_ERASE is set

From: Tudor Ambarus
Date: Sat Nov 06 2021 - 03:56:32 EST


SPI_NOR_NO_ERASE is used either by F-RAMs, or MRAMs, or EEPROMs,
neither of which supports SFDP, so once SPI_NOR_NO_ERASE is set,
SFDP can not undo it. These type of flashes should be moved out of
the SPI NOR core anyway, so don't complicate things and just skip
the erase logic when SPI_NOR_NO_ERASE is set. Normally SPI NOR core
should operate just on SNOR_F flags, but since SPI_NOR_NO_ERASE
should be removed, don't bother with extra code.

Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
---
drivers/mtd/spi-nor/core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index a1b5d5432f41..52c82d943499 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2680,6 +2680,9 @@ static void spi_nor_skip_sfdp_init_params(struct spi_nor *nor)
SPINOR_OP_PP, SNOR_PROTO_8_8_8_DTR);
}

+ if (info_flags & SPI_NOR_NO_ERASE)
+ return;
+
/*
* Sector Erase settings. Sort Erase Types in ascending order, with the
* smallest erase size starting at BIT(0).
@@ -3195,12 +3198,13 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
mtd->name = dev_name(dev);
mtd->type = MTD_NORFLASH;
mtd->flags = MTD_CAP_NORFLASH;
- if (nor->info->flags & SPI_NOR_NO_ERASE)
+ if (nor->info->flags & SPI_NOR_NO_ERASE) {
+ mtd->_erase = spi_nor_erase;
mtd->flags |= MTD_NO_ERASE;
+ }
mtd->writesize = nor->params->writesize;
mtd->writebufsize = nor->params->page_size;
mtd->size = nor->params->size;
- mtd->_erase = spi_nor_erase;
mtd->_read = spi_nor_read;
/* Might be already set by some SST flashes. */
if (!mtd->_write)
--
2.25.1