5.15-stable review patch. If anyone has any objections, please let me know.
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From: Maciej Andrzejewski maciej.andrzejewski@m-works.net
commit b086a46dae48829e11c0c02580e30d920b76743c 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: acbd3d0945f9 ("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 --- drivers/mtd/nand/raw/arasan-nand-controller.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/mtd/nand/raw/arasan-nand-controller.c +++ b/drivers/mtd/nand/raw/arasan-nand-controller.c @@ -1425,8 +1425,8 @@ static int anfc_parse_cs(struct arasan_n * case, the "not" chosen CS is assigned to nfc->spare_cs and selected * whenever a GPIO CS must be asserted. */ - if (nfc->cs_array && nfc->ncs > 2) { - if (!nfc->cs_array[0] && !nfc->cs_array[1]) { + if (nfc->cs_array) { + if (nfc->ncs > 2 && !nfc->cs_array[0] && !nfc->cs_array[1]) { dev_err(nfc->dev, "Assign a single native CS when using GPIOs\n"); return -EINVAL;