mtd: rawnand: arasan: Fix double assertion of chip-select

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commit b086a46dae upstream.

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.

Fixes: acbd3d0945 ("mtd: rawnand: arasan: Leverage additional GPIO CS")
Cc: stable@vger.kernel.org
Signed-off-by: Maciej Andrzejewski <maciej.andrzejewski@m-works.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Maciej Andrzejewski 2024-12-02 13:51:07 +01:00 • committed by Greg Kroah-Hartman

parent 4b13d0d186

commit 326d7fb3e4

1 changed files with 2 additions and 2 deletions

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drivers/mtd/nand/raw/arasan-nand-controller.c

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