drm: add support for monotonic vblank timestamps
authorImre Deak <imre.deak@intel.com>
Tue, 23 Oct 2012 18:53:26 +0000 (18:53 +0000)
committerDave Airlie <airlied@redhat.com>
Tue, 20 Nov 2012 06:06:16 +0000 (16:06 +1000)
commitc61eef726a78ae77b6ce223d01ea2130f465fe5c
tree7bd310556195005b5c4c1cbadadc9da1fbf5163c
parente62f2f5acba1d466da047983ae16f6b96b68b310
drm: add support for monotonic vblank timestamps

Jumps in the vblank and page flip event timestamps cause trouble for
clients, so we should avoid them. The timestamp we get currently with
gettimeofday can jump, so use instead monotonic timestamps.

For backward compatibility use a module flag to revert back to using
gettimeofday timestamps. Add also a DRM_CAP_TIMESTAMP_MONOTONIC flag
that is simply a read only version of the module flag, so that clients
can query this without depending on sysfs.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/drm_ioctl.c
drivers/gpu/drm/drm_irq.c
drivers/gpu/drm/drm_stub.c
include/drm/drmP.h
include/uapi/drm/drm.h