If you are using a devicetree overlay, then SPI DMA won’t work. You have to build the driver into the base devicetree using dtb-rebuilder to get DMA to work with your SPI driver.
Regards, John > On Feb 17, 2016, at 5:55 AM, pauldaniel...@gmail.com wrote: > > Related question: I'm using the towertech CAN cape (mcp2515) and seeing a lot > of CPU usage by the spi process. For example, just connecting one interface > to an active bus gives 30-50% CPU usage, and that doesn't include actually > doing anything with the data! I'm running debian with kernel 3.8.13-bone70 > and using the driver source they provide (mcp2515). Is this a known issue? > Has it been addressed in more recent kernels? Thanks! > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com > <mailto:beagleboard+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/0995AD0C-2685-4015-A6B6-C7F6174F50DC%40gmail.com. For more options, visit https://groups.google.com/d/optout.
