On 02.08.2016 16:04, Daniel Vetter wrote:
If you mean "add a generic hw-accelerated bitblt operation": This is not hw drm works. The generic kms stuff is about display only, with just very basic (hence "dumb") buffer allocation support in a generic way.
Well, if it already does buffer allocation and mapping (which might also involve copying around phyisical buffers), why not also add copy-between-buffers ?
If you mean "expose the dma engine I have here to userspace in driver-private ioctls with the trade-off logic between that, kms compositing using the display block and memcpy in userspace", then go ahead ;-) But if you do that, pls don't don't forget that for any uapi the drm subsytem requires correspoding open source userspace (in a real app/compositor, not just some toy test or something similar).
I dont intent to add yet another specific driver and driver-specific ioctl()s, but instead a generic interface. Such stuff needs kernel support and kernel configuration anyways, so I'd like to keep it out of userland's business.
--mtx