On Wed, 3 Mar 2010 15:25:52 +0800 David Brownell <davi...@pacbell.net> wrote:
> If someone decided to update a SPI controller driver to avoid DMA in > some cases, in favor of PIO, they could already code such heuristics > without needing your proposed hinting from upper layers. > > The result in the low-level driver would be just to use a different > test (maybe "is this a one-word transfer?" instead of checking your > per-transfer "use PIO?" hint) Yup, good point, controller driver can be smarter Thanks, Feng > before kicking in whatever logic you > think would improve performance (by eliminating DMA setup and teardown > costs, including cache cleaning). > > - Dave > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
