Re: [PATCH] spi: spi-davinci: deassert CS on setup()

[Ben Gardiner]

Hi Trent,

Thanks for the quick review.

On Tue, Sep 10, 2013 at 10:44 PM, Trent Piepho <tpiepho@xxxxxxxxx> wrote:
>
> It is supposed to be possible to call setup() on one slave while
> transfers on another slave attached to the same master are in
> progress.
>
> A cursory look at the code makes it seem that all the CS control bits
> share SPIDAT1?  Will writing to SPIDAT1 in davinci_spi_chipselect()
> cause a race if another chipselect is being used?

Good point. I think you're right there could be a race.

I tested with multiple slaves and hammered the bus with concurrent
accesses; but that doesn't mean that there _isn't_ still a race.

Can you recommend an existing implementation in-tree upon which I can
base a new patch to add concurrency protection to SPIDAT1 accesses?
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