[PATCH 3/4] spi: bcm2835aux: set up spi-mode before asserting cs-gpio

Mark Brown broonie at kernel.org
Wed Feb 10 00:01:49 PST 2016

On Tue, Feb 09, 2016 at 03:49:24PM -0800, Eric Anholt wrote:

> This patch surprised me.  I would have thought that the solution was to
> just write the updated CNTL bits for CPOL and wait a moment whenever it
> changes.  The CS only gets asserted later on when we get some data in
> the TX FIFO, so I think you're just reducing the chance of losing the
> race to get our inverted clock noticed by the device before the CS gets
> asserted.

We support (and generally want to use since hardware chip selects are
often very limited in what they do) chip select on GPIO.
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