Re: SPI not working on 5.10 and 5.11, bisected to 766c6b63aa04 ("spi: fix client driver breakages when using GPIO descriptors")

On Thu, Jan 14, 2021 at 12:27:42PM +0100, Christophe Leroy wrote:

Today I have in the DTS the CS GPIOs declared as ACTIVE_LOW.

If I declare them as ACTIVE_HIGH instead, then I also have to set
spi-cs-high property, otherwise of_gpio_flags_quirks() is not happy and
forces the GPIO ACTIVE LOW.

When I set spi-cs-high property, it sets the SPI_CS_HIGH bit in spi->mode.

OK, so it sounds like you want SPI_CS_HIGH and that is being set
correctly?

In fsl_spi_chipselect(), we have

	bool pol = spi->mode & SPI_CS_HIGH

Then
	pdata->cs_control(spi, pol);

So changing the board config is compensated by the above, and at the end it still doesn't work.

This is a driver bug, the driver set_cs() operation should not be
modifying the value it is told to set.