[PATCH] mtd: nand: cadence: Fix device assignment to avoid warm reset issue

[Michael Nazzareno Trimarchi]

Hi

Il mar 19 ago 2025, 07:22 <dinesh.maniyam at altera.com> ha scritto:

> From: Dinesh Maniyam <dinesh.maniyam at intel.com>
>
> The driver currently does:
>     mtd->dev->parent = cadence->dev;
>
> This works in Linux because `struct mtd_info` embeds a `struct device`,
> so `mtd->dev` is always valid and its `.parent` can be set.
>
> In U-Boot, however, `mtd->dev` is only a pointer to a `struct udevice`.
> Dereferencing it before assignment is invalid, which breaks the device
> hierarchy. As a result, consumers relying on `mtd->dev` (e.g. partition
> parser, reset and re-init paths) operate on a dangling pointer. This
> leads to failures during warm reset when the NAND device is accessed
> again.
>
> Fix by assigning the device pointer directly:
>     mtd->dev = cadence->dev;
>
> This matches U-Boot’s device model, preserves a valid hierarchy, and
> resolves the warm reset issue on Cadence NAND.
>


Please add commit that it fixes

Michael

>
> Signed-off-by: Dinesh Maniyam <dinesh.maniyam at intel.com>
> ---
>  drivers/mtd/nand/raw/cadence_nand.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/cadence_nand.c
> b/drivers/mtd/nand/raw/cadence_nand.c
> index 27aa7f97a45..4771440d1de 100644
> --- a/drivers/mtd/nand/raw/cadence_nand.c
> +++ b/drivers/mtd/nand/raw/cadence_nand.c
> @@ -2196,7 +2196,7 @@ static int cadence_nand_chip_init(struct
> cadence_nand_info *cadence, ofnode node
>         chip->controller = &cadence->controller;
>         nand_set_flash_node(chip, node);
>         mtd = nand_to_mtd(chip);
> -       mtd->dev->parent = cadence->dev;
> +       mtd->dev = cadence->dev;
>
>         chip->options |= NAND_BUSWIDTH_AUTO;
>         chip->select_chip = cadence_nand_select_chip;
> --
> 2.35.3
>
>