I'm working on getting Android working with DRM drivers. ATM, I'm using virtio-gpu as the driver and trying to get just KMS side working without rendering. I have it working with stock AOSP and the emulated fb with a few additions to the virtio-gpu driver[1]. Now I'm trying to get things working with native KMS using drm_gralloc and drm_hwcomposer (now in AOSP). I've hit one problem though which I'm not sure how to solve without hacking around it.
Is prime allowed on dumb BOs? AIUI, dumb buffer allocation is not allowed on render nodes and drmPrimeHandleToFD is not allowed on card0, so I'm stuck. I could open both nodes, but then I want the case of no render node to work. After some searching, I thought it was a matter of needing to do drmAuthMagic, but then found that is considered obsolete[2].
Rob
[1] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git android-4.4 [2] http://www.x.org/wiki/Events/XDC2013/XDC2013DavidHerrmannDRMSecurity/slides....