Re: [PATCH] spi: sun6i: Set SPI mode in prepare_message

[Mark Brown]

On Mon, Apr 20, 2026 at 10:46:04AM -0600, Kevin Mehall wrote:

> With a GPIO chip select, CS is asserted before entering transfer_one.
> The spi-sun6i driver previously configured the SPI mode (including clock
> polarity) and enabled the bus in transfer_one, which can cause an
> extraneous SCK transition with CS asserted, corrupting the transferred
> data.

> This patch moves the SPI mode configuration and bus enable to the
> spi_prepare_message callback, ensuring that SCK is driven to the correct
> level prior to asserting CS.

> +	/* We want to control the chip select manually */
> +	reg |= SUN6I_TFR_CTL_CS_MANUAL;
> +
> +	sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);

Might this cause the native chip select to get asserted, we didn't set
up values so it'll have defaults if it wasn't previously configured?

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