If you don't specify buswidth 2 (16 bits) in the device tree, FSMC doesn't even probe anymore:

fsmc-nand 10100000.flash: FSMC device partno 090, manufacturer 80, revision 00, config 00 nand: device found, Manufacturer ID: 0x20, Chip ID: 0xb1 nand: ST Micro 10100000.flash nand: bus width 8 instead of 16 bits nand: No NAND device found fsmc-nand 10100000.flash: probe with driver fsmc-nand failed with error -22

With this patch to use autodetection unless buswidth is specified, the device is properly detected again:

fsmc-nand 10100000.flash: FSMC device partno 090, manufacturer 80, revision 00, config 00 nand: device found, Manufacturer ID: 0x20, Chip ID: 0xb1 nand: ST Micro NAND 128MiB 1,8V 16-bit nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64 fsmc-nand 10100000.flash: Using 1-bit HW ECC scheme Scanning device for bad blocks

I don't know where or how this happened, I think some change in the nand core.

Cc: stable@vger.kernel.org Signed-off-by: Linus Walleij linus.walleij@linaro.org --- Changes in v2: - Drop surplus semicolon. - Also add NAND_BUSWIDTH_AUTO if 8bit buswidth is specified. - Link to v1: https://lore.kernel.org/r/20250914-fsmc-v1-1-6d86d8b48552@linaro.org --- drivers/mtd/nand/raw/fsmc_nand.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/fsmc_nand.c b/drivers/mtd/nand/raw/fsmc_nand.c index df61db8ce466593d533e617c141a8d2498b3a180..b13b2b0c3f300c7a611a36a402f1587d28166fab 100644 --- a/drivers/mtd/nand/raw/fsmc_nand.c +++ b/drivers/mtd/nand/raw/fsmc_nand.c @@ -876,10 +876,14 @@ static int fsmc_nand_probe_config_dt(struct platform_device *pdev, if (!of_property_read_u32(np, "bank-width", &val)) { if (val == 2) { nand->options |= NAND_BUSWIDTH_16; - } else if (val != 1) { + } else if (val == 1) { + nand->options |= NAND_BUSWIDTH_AUTO; + } else { dev_err(&pdev->dev, "invalid bank-width %u\n", val); return -EINVAL; } + } else { + nand->options |= NAND_BUSWIDTH_AUTO; }

if (of_property_read_bool(np, "nand-skip-bbtscan"))

--- base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585 change-id: 20250914-fsmc-bd18e1a8116f

Best regards,