From 4095f4d9225a64921a6ee4bb8dbc94c6edc2df08 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Thu, 18 May 2023 08:54:40 +0000 Subject: [PATCH] mtd: spi-nor: Fix divide by zero for spi-nor-generic flashes We failed to initialize n_banks for spi-nor-generic flashes, which caused a devide by zero when computing the bank_size. By default we consider that all chips have a single bank. Initialize the default number of banks for spi-nor-generic flashes. Even if the bug is fixed with this simple initialization, check the n_banks value before dividing so that we make sure this kind of bug won't occur again if some other struct instance is created uninitialized. Suggested-by: Todd Brandt Reported-by: Todd Brandt Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217448 Fixes: 9d6c5d64f028 ("mtd: spi-nor: Introduce the concept of bank") Link: https://lore.kernel.org/all/20230516225108.29194-1-todd.e.brandt@intel.com/ Signed-off-by: Tudor Ambarus Tested-by: Todd Brandt Reviewed-by: Miquel Raynal Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230518085440.2363676-1-tudor.ambarus@linaro.org --- drivers/mtd/spi-nor/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 0bb0ad14a2fc..5f29fac8669a 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2018,6 +2018,7 @@ static const struct spi_nor_manufacturer *manufacturers[] = { static const struct flash_info spi_nor_generic_flash = { .name = "spi-nor-generic", + .n_banks = 1, /* * JESD216 rev A doesn't specify the page size, therefore we need a * sane default. @@ -2921,7 +2922,8 @@ static void spi_nor_late_init_params(struct spi_nor *nor) if (nor->flags & SNOR_F_HAS_LOCK && !nor->params->locking_ops) spi_nor_init_default_locking_ops(nor); - nor->params->bank_size = div64_u64(nor->params->size, nor->info->n_banks); + if (nor->info->n_banks > 1) + params->bank_size = div64_u64(params->size, nor->info->n_banks); } /** @@ -2987,6 +2989,7 @@ static void spi_nor_init_default_params(struct spi_nor *nor) /* Set SPI NOR sizes. */ params->writesize = 1; params->size = (u64)info->sector_size * info->n_sectors; + params->bank_size = params->size; params->page_size = info->page_size; if (!(info->flags & SPI_NOR_NO_FR)) {