[PATCH] mmc: mxs-mmc: add support for pre_req and post_req

Per Forlin per.forlin at linaro.org
Thu Apr 21 04:46:18 EDT 2011

On 21 April 2011 08:29, Shawn Guo <shawn.guo at freescale.com> wrote:
> On Wed, Apr 20, 2011 at 05:30:22PM +0200, Per Forlin wrote:
> [...]
>> Remove dma_map and dma_unmap from your host driver and run the tests
>> (obviously nonblocking and blocking will have the same results). If
>> there is still no performance gain the cache penalty is very small on
>> your platform and therefore nonblocking doesn't improve things much.
>> Please let me know the result.
> Sorry, I could not understand.  What's the point to run the test when
> the driver is even broken.  The removal of  dma_map_sg and
> dma_unmap_sg makes mxs-mmc host driver broken.
The point is only to get a measurement of the cost of handling
dma_map_sg and dma_unmap_sg, this is the maximum time mmc nonblocking
can save.
The nonblocking mmc_test should save the total time of dma_map_sg and
dma_unmap_sg, if the pre_req and post_req hooks are implemented
Running without dma_map_sg and dma_unmap_sg will confirm if the
pre_req and post_req hooks are implemented correctly.

> --
> Regards,
> Shawn

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