Re: [PATCH v5] spi: spi-ti-qspi: Add DMA support for QSPI mmap read

From	Mark Brown <broonie@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5] spi: spi-ti-qspi: Add DMA support for QSPI mmap read
Date	2016-08-16 20:50 +0200
Message-ID	<s6RAZ-6EN-3@gated-at.bofh.it> (permalink)
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On Tue, Aug 09, 2016 at 06:20:01PM +0530, Vignesh R wrote:
> 
> 

> According to this thread[1], converting virtual address
> pointer into scatterlist which is then DMA mapped is unsafe on systems
> with certain cache architecture. Hence, I added code to handle kmap
> buffers inside the driver rather than updating generic spi-core code.

That's saying that things that aren't covered aren't DMAable safely at
all which is a more general issue...

> If its okay to update the spi_map_buf() to handle kmap buffers as above
> then I can submit the patch accordingly.

Yes, the whole point is that this is all in generic code so drivers
don't need to worry about it.

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Re: [PATCH v5] spi: spi-ti-qspi: Add DMA support for QSPI mmap read Mark Brown <broonie@kernel.org> - 2016-08-16 20:50 +0200
  Re: [PATCH v5] spi: spi-ti-qspi: Add DMA support for QSPI mmap read Vignesh R <vigneshr@ti.com> - 2016-08-17 07:20 +0200

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