On Thu, Jan 24, 2013 at 01:56:21PM +0100, Marek Vasut wrote: > Add support for the PIO mode and mixed PIO/DMA mode support. The mixed > PIO/DMA is the default mode of operation. This shall leverage overhead > that the driver creates due to setting up DMA descriptors even for very > short transfers. > > The current boundary between PIO/DMA 8 bytes, transfers shorter than 8 > bytes are transfered by PIO, longer transfers use DMA. The performance > of write transfers remains unchanged, while there is a minor improvement > of read performance. Reading 16KB EEPROM with DMA-only operations gives > a read speed of 39.5KB/s, while with then new mixed-mode the speed is > blazing 40.6KB/s. > > Signed-off-by: Marek Vasut <[email protected]> > Cc: Fabio Estevam <[email protected]> > Cc: Shawn Guo <[email protected]> > Cc: Wolfram Sang <[email protected]>
OK, the polling can be argued. I shortened the comment about the threshold a little, since bandwidth measurements depend on a lot of other things and it is not really needed there. Applied to -next, thanks! -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
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