[PATCH 5.17 0068/1126] mtd: spi-nor: Skip erase logic when SPI_NOR_NO_ERASE is set

From: Greg Kroah-Hartman
Date: Tue Apr 05 2022 - 03:47:23 EST

From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>

commit 151c6b49d679872d6fc0b50e0ad96303091694a2 upstream.

Even if SPI_NOR_NO_ERASE was set, one could still send erase opcodes
to the flash. It is not recommended to send unsupported opcodes to
flashes. Fix the logic and do not set mtd->_erase when SPI_NOR_NO_ERASE
is specified. With this users will not be able to issue erase opcodes to
flashes and instead they will recive an -ENOTSUPP error.

Fixes: b199489d37b2 ("mtd: spi-nor: add the framework for SPI NOR")
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Reviewed-by: Michael Walle <michael@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20220228163334.277730-1-tudor.ambarus@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/mtd/spi-nor/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3181,10 +3181,11 @@ static void spi_nor_set_mtd_info(struct
mtd->flags = MTD_CAP_NORFLASH;
if (nor->info->flags & SPI_NOR_NO_ERASE)
mtd->flags |= MTD_NO_ERASE;
+ else
+ mtd->_erase = spi_nor_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)