[PATCH v4] mmc: documentation of mmc non-blocking request usage and design.

[Randy Dunlap]

On Tue,  5 Jul 2011 23:35:32 +0200 Per Forlin wrote:

> +MMC block driver
> +================
> +
> +The issue_rw_rq() in the MMC block driver is made non-blocking.
> +The increase in throughput is proportional to the time it takes to
> +prepare (major part of preparations are dma_map_sg and dma_unmap_sg)
> +a request and how fast the memory is. The faster the MMC/SD is
> +the more significant the prepare request time becomes. Roughly the expected
> +performance gain is 5% for large writes and 10% on large reads on a L2 cache
> +platform. In power save mode, when clocks run on a lower frequency, the DMA
> +preparation may cost even more. As long as these slower preparations are run
> +in parallel with the transfer performance wont be affected.

                                             won't

Acked-by: Randy Dunlap <rdunlap at xenotime.net>


thanks.
---
~Randy
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