• Jason Ekstrand's avatar
    drm/syncobj: Add a signal ioctl (v3) · ffa9443f
    Jason Ekstrand authored
    This IOCTL provides a mechanism for userspace to trigger a sync object
    directly.  There are other ways that userspace can trigger a syncobj
    such as submitting a dummy batch somewhere or hanging on to a triggered
    sync_file and doing an import.  This just provides an easy way to
    manually trigger the sync object without weird hacks.
    
    The motivation for this IOCTL is Vulkan fences.  Vulkan lets you create
    a fence already in the signaled state so that you can wait on it
    immediatly without stalling.  We could also handle this with a new
    create flag to ask the driver to create a syncobj that is already
    signaled but the IOCTL seemed a bit cleaner and more generic.
    
    v2:
     - Take an array of sync objects (Dave Airlie)
    v3:
     - Throw -EINVAL if pad != 0
    Signed-off-by: default avatarJason Ekstrand <jason@jlekstrand.net>
    Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
    ffa9443f
drm_syncobj.c 22.4 KB