This is a note to let you know that I've just added the patch titled mtd: nand: make Samsung SLC NAND usable again to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mtd-nand-make-samsung-slc-nand-usable-again.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 69fc01296c92814b62dbfba1600fe7ed2ed304f5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= <LW@xxxxxxxxxxxxxxxxxxx> Date: Tue, 29 Aug 2017 12:17:12 +0200 Subject: mtd: nand: make Samsung SLC NAND usable again MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx> commit 69fc01296c92814b62dbfba1600fe7ed2ed304f5 upstream. 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 using nand_is_slc(). With the offending commit this call is skipped, leaving chip->bits_per_cell cleared to zero when the manufacturer specific '.detect' function calls nand_is_slc() which in turn interprets bits_per_cell != 1 as indication for an MLC chip. 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. Fixes: c51d0ac59f24 ("mtd: nand: Move Samsung specific init/detection logic in nand_samsung.c") Signed-off-by: Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mtd/nand/nand_base.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -3993,10 +3993,13 @@ static void nand_manufacturer_detect(str * 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); + } } /* Patches currently in stable-queue which might be from LW@xxxxxxxxxxxxxxxxxxx are queue-4.13/mtd-nand-make-samsung-slc-nand-usable-again.patch