From f8813c6431971322ef813b39bf41d21c7f40b9c7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Lothar=20Wa=C3=9Fmann?= Date: Tue, 29 Aug 2017 12:06:47 +0200 Subject: [PATCH] mtd: nand: make Samsung SLC NAND usable again commit c51d0ac59f24 ("mtd: nand: Move Samsung specific init/detection logic in nand_samsung.c") introduced a regression for Samsung SLC NAND chips. Prior to this commit chip->bits_per_cell was initialized by calling nand_get_bits_per_cell() before interpreting the ID bytes retrieved from the chip. With the offending commit this call is skipped, leaving chip->bits_per_cell cleared to zero when the manufacturer specific '.detect' function is called. This is interpreted by nand_is_slc() as an indicator for an MLC chip (bits_per_cell != 1). The effect is that e.g. a K9F1G08U0F NAND chip is falsely detected as MLC NAND with 4KiB page size rather than SLC with 2KiB page size. Add a call to nand_get_bits_per_cell() before calling the .detect hook function in nand_manufacturer_detect(), so that the nand_is_slc() calls in the manufacturer specific code will return correct results. --- drivers/mtd/nand/nand_base.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index c6c18b82f8f4..c05cf874cbb8 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -3993,10 +3993,13 @@ static void nand_manufacturer_detect(struct nand_chip *chip) * nand_decode_ext_id() otherwise. */ if (chip->manufacturer.desc && chip->manufacturer.desc->ops && - chip->manufacturer.desc->ops->detect) + chip->manufacturer.desc->ops->detect) { + /* The 3rd id byte holds MLC / multichip data */ + chip->bits_per_cell = nand_get_bits_per_cell(chip->id.data[2]); chip->manufacturer.desc->ops->detect(chip); - else + } else { nand_decode_ext_id(chip); + } } /* -- 2.39.2