[PATCH] mtd: rawnand: arasan: Fix double assertion of chip-select

[Miquel Raynal]

Hi Maciej,

On 23/11/2024 at 20:20:21 +01, Maciej Andrzejewski <maciej.andrzejewski at m-works.net> wrote:

> When two chip-selects are configured in the device tree, and the second is
> a non-native GPIO, both the GPIO-based chip-select and the first native
> chip-select may be asserted simultaneously. This double assertion causes
> incorrect read and write operations.
>
> The issue occurs because when nfc->ncs <= 2, nfc->spare_cs is always
> initialized to 0 due to static initialization. Consequently, when the
> second chip-select (GPIO-based) is selected in anfc_assert_cs(), it is
> detected by anfc_is_gpio_cs(), and nfc->native_cs is assigned the value 0.
> This results in both the GPIO-based chip-select being asserted and the
> NAND controller register receiving 0, erroneously selecting the native
> chip-select.
>
> This patch resolves the issue, as confirmed by oscilloscope testing with
> configurations involving two or more chip-selects in the device tree.
>

Ok to me, can you please send a v2 with correct Fixes and Cc: stable
tags, please?

Thanks,
Miquèl