On 21-06-20, 22:36, Federico Vaga wrote: > On Sun, Jun 21, 2020 at 12:54:57PM +0530, Vinod Koul wrote: > > 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. > > I was thinking about a dedicated module, and not something that the DMA engine > offers directly. You load the module only if you need it (like the test module) But loading that module would expose dma to userspace. > > > Federico, what use case do you have in mind? > > Userspace drivers more the reason not do do so, why cant a kernel driver be added for your usage? -- ~Vinod
