Commit 4095f4d9 authored by Tudor Ambarus's avatar Tudor Ambarus Committed by Miquel Raynal
Browse files

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: default avatarTodd Brandt <todd.e.brandt@linux.intel.com>
Reported-by: default avatarTodd Brandt <todd.e.brandt@linux.intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217448
Fixes: 9d6c5d64 ("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: default avatarTudor Ambarus <tudor.ambarus@linaro.org>
Tested-by: default avatarTodd Brandt <todd.e.brandt@linux.intel.com>
Reviewed-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230518085440.2363676-1-tudor.ambarus@linaro.org
parent 650a8884

drivers/mtd/spi-nor/core.c

+4 −1
Original line number Diff line number Diff line
@@ -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)) {