[PATCH v4 1/2] spi: implemented driver for Cirrus EP93xx SPI controller

[Martin Guy]

On 4/22/10, H Hartley Sweeten <hartleys at visionengravers.com> wrote:
>  > Further, on a suspicion about the silliness of the per-transfer
>  > bits_per_word being checked right down the bottom of the lowest lever
>  > byte-read/writing routine instead of once per transfer, I split
>  > ep93xx_spi_read and _write into 8 and 16-bit variants, and checked
>  > t->bits_per_word once outside the read and write loops.
>  >
>  > This gives:
>  >      60.0% 59.3%  285906 irq/MB
>
>
> It looks like splitting the 8/16-bit read/write routines does help
>  with cpu usage compared to the tests above.  Was the data transfer
>  (kB/sec) any better?

No, exactly the same.