Re: [PATCH v2] spi: ma35d1-qspi: Enable GPIO chip selects

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The driver improperly restricts the total number of chip selects (`num_cs`) to the hardware's native maximum, causing probe to fail for valid device tree configurations that explicitly declare additional GPIO chip selects.
--

--- Patch [1]: [PATCH v2] spi: ma35d1-qspi: Enable GPIO chip selects ---
commit 9b36effcfaa138327c6207a2889e09445f4ecaba
Author: Chi-Wen Weng <cwweng@nuvoton.com>

spi: ma35d1-qspi: Enable GPIO chip selects

The generic SPI controller binding allows GPIO-based chip selects, but
the MA35D1 QSPI driver does not currently enable the SPI core's GPIO
descriptor handling. Enable GPIO chip-select support and specify that
the controller provides two native chip selects.

> diff --git a/drivers/spi/spi-ma35d1-qspi.c b/drivers/spi/spi-ma35d1-qspi.c
> index 541d5d72484cf..60e082de58f51 100644
> --- a/drivers/spi/spi-ma35d1-qspi.c
> +++ b/drivers/spi/spi-ma35d1-qspi.c

[ ... ]

> @@ -613,10 +624,13 @@ static int nuvoton_qspi_probe(struct platform_device *pdev)
>  				     num_cs);
>  
>  	ctlr->num_chipselect = num_cs;
> +	ctlr->max_native_cs = NUVOTON_QSPI_MAX_NUM_CS;
> +	ctlr->use_gpio_descriptors = true;

[Severity: Medium]
Since this patch enables GPIO chip selects, shouldn't the driver allow
configurations where the total number of chip selects exceeds the native
maximum?

In nuvoton_qspi_probe() just above this diff, there is a check:

	if (!num_cs || num_cs > NUVOTON_QSPI_MAX_NUM_CS)
		return dev_err_probe(dev, -EINVAL, "invalid num-cs %u\n",
				     num_cs);

If a device tree explicitly defines a higher value for num-cs (for example
num-cs = <3>) to declare additional GPIO chip selects alongside the native
ones, this check will cause the probe to fail with -EINVAL, preventing
any devices on the bus from functioning.

>  	ctlr->max_transfer_size = nuvoton_qspi_max_transfer_size;
>  	ctlr->max_message_size = nuvoton_qspi_max_message_size;
>  	ctlr->mem_ops = &nuvoton_qspi_mem_ops;
>  	ctlr->mem_caps = &nuvoton_qspi_mem_caps;
> +	ctlr->setup = nuvoton_qspi_setup;
>  	ctlr->set_cs = nuvoton_qspi_set_cs;
>  	ctlr->transfer_one = nuvoton_qspi_transfer_one;
>  	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260803062444.1649057-1-cwweng.linux@gmail.com?part=1