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Re: [PATCH 1/8] Documentation/spi/spidev_test.c: use one rx buffer

From Joshua Clayton <stillcompiling@gmail.com>
Newsgroups linux.kernel
Subject Re: [PATCH 1/8] Documentation/spi/spidev_test.c: use one rx buffer
Date 2015-11-17 20:00 +0100
Message-ID <qvTDX-m1-1@gated-at.bofh.it> (permalink)
References <qvQmJ-6NX-7@gated-at.bofh.it> <qvQmJ-6NX-5@gated-at.bofh.it> <qvSyf-8a9-17@gated-at.bofh.it>
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On Tuesday, November 17, 2015 05:41:56 PM Mark Brown wrote:
> On Tue, Nov 17, 2015 at 07:24:21AM -0800, Joshua Clayton wrote:
> 
> > default_rx and rx are needlessly different.
> > Use one buffer, local to transmit()
> 
> Why?  This isn't what I'd expect from black boxing the API, from a
> userspace point of view the transfer is atomic and in an ideal world
> we'd be able to do direct to/from memory transfers rather than memcpy()
> into kernel space which means that userspace should assume the transfers
> are going on simultaneously even if they don't currently.

The important thing here was to get rid of the default_rx buffer.
I just noticed that the output can be set up completely within the scope
of the transmit function, since the operands are global. But I would be
just as happy to set it up at the top level. I'll change this in V2

--
~Joshua Clayton
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[PATCH 1/8] Documentation/spi/spidev_test.c: use one rx buffer Joshua Clayton <stillcompiling@gmail.com> - 2015-11-17 16:30 +0100
  Re: [PATCH 1/8] Documentation/spi/spidev_test.c: use one rx buffer Mark Brown <broonie@kernel.org> - 2015-11-17 18:50 +0100
    Re: [PATCH 1/8] Documentation/spi/spidev_test.c: use one rx buffer Joshua Clayton <stillcompiling@gmail.com> - 2015-11-17 20:00 +0100

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