On 19-06-20, 16:31, Dave Jiang wrote: > > > On 6/19/2020 3:47 PM, Federico Vaga wrote: > > Hello, > > > > is there the possibility of using a DMA engine channel from userspace? > > > > Something like: > > - configure DMA using ioctl() (or whatever configuration mechanism) > > - read() or write() to trigger the transfer > > > > I may have supposedly promised Vinod to look into possibly providing > something like this in the future. But I have not gotten around to do that > yet. Currently, no such support. And I do still have serious reservations about this topic :) Opening up userspace access to DMA does not sound very great from security point of view. Federico, what use case do you have in mind? We should keep in mind dmaengine is an in-kernel interface providing services to various subsystems, so you go thru the respective subsystem kernel interface (network, display, spi, audio etc..) which would in turn use dmaengine. -- ~Vinod
