On Fri, Jun 19, 2020 at 01:31:18PM +0200, Lars Povlsen wrote:

+/*
+ * The Designware SPI controller (referred to as master in the
+ * documentation) automatically deasserts chip select when the tx fifo
+ * is empty. The chip selects then needs to be driven by a CS override
+ * register. enable is an active low signal.
+ */
+static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool nEnable)

The value that is passed in here is the value that should be driven on
the output pin, the driver should not be interpreting the value in any
way here.  Documenting it as nEnable adds a layer of confusion, and it
may not be an active high signal depending on the system.

+	if (!nEnable) {
+		/* Ensure CS toggles, so start off all disabled */
+		regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0);
+		/* CS override drive enable */
+		regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1);

This should just be setting the value to whatever the core asked for it
to be set to, the driver adding extra toggles is likely to disrupt
things.