The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 151c6b49d679872d6fc0b50e0ad96303091694a2 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus tudor.ambarus@microchip.com Date: Mon, 28 Feb 2022 18:33:34 +0200 Subject: [PATCH] mtd: spi-nor: Skip erase logic when SPI_NOR_NO_ERASE is set

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@microchip.com Reviewed-by: Michael Walle michael@walle.cc Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220228163334.277730-1-tudor.ambarus@microchip.co...

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 9014008e60b3..b4f141ad9c9c 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2948,10 +2948,11 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor) 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)