First of all, do not remove mailing lists from Cc and people if you
are not sure they do not need your stuff.

On Mon, May 14, 2018 at 11:11 AM, Radu Pirea [off-list ref] wrote:

On Sun, 2018-05-13 at 16:33 +0300, Andy Shevchenko wrote:

quoted

On Fri, May 11, 2018 at 1:38 PM, Radu Pirea <radu.pirea@microchip.com

quoted

wrote:

quoted

quoted

+static void at91_usart_spi_cleanup(struct spi_device *spi)
+{
+       struct at91_usart_spi_device *ausd = spi->controller_state;
+
+       if (!ausd)
+               return;

Is it even possible?

Theoretically yes.

I would like to know real circumstances when it might happen.

quoted

Anyway the code below will work fine even if it's the case.

quoted

+
+       spi->controller_state = NULL;
+       kfree(ausd);
+}

quoted

The question is, why you didn't utilize what SPI core provides you?

I tried, but it did not work the way I expected.

So, what is not going as expected in "SPI core takes care of CSs" case?
Did you use oscilloscope for that?

-- 
With Best Regards,
Andy Shevchenko