From: Rob Clark <rob@xxxxxx>
This is following a bit the approach that Ville is taking for atomic-
modeset, in that it is switching over to using properties for everything.
The advantage of this approach is that it makes it easier to add new
attributes to set as part of a page-flip (and even opens the option to
add new object types).
The basic principles are:
a) split out object state (in this case, plane and crtc, although I
expect more to be added as atomic-modeset is added) into seperate
structures that can be atomically commited or rolled back. The
property values array is also split out into the state structs,
so that the property values visible to userspace automatically
reflect the current state (ie. property changes are either
committed or discarded depending on whether the state changes
are committed or discarded).
b) expand the object property API (set_property()) to take a state
object. The obj->set_property() simply updates the state object
without actually applying the changes to the hw.
c) after all the property updates are done, the updated state can
be checked for correctness and against the hw capabilities, and
then either discarded or committed atomically.
Since we need to include properties in the atomic-pageflip scheme,
doing everything via properties avoids updating a bunch of additional
driver provided callbacks. Instead we just drop crtc->page_flip()
and plane->update_plane(). By splitting out the object's mutable
state into drm_{plane,crtc,etc}_state structs (which are wrapped by
the individual drivers to add their own hw specific state), we can
use some helpers (drm_{plane,crtc,etc}_set_property() and
drm_{plane,crtc,etc}_check_state()) to keep core error checking in
drm core and avoid pushing the burden of dealing with common
properties to the individual drivers.
The intention is for this to also simplify atomic-modeset, by
providing some of the necessary infrastructure (object property types,
signed property values, and property's whose usespace visible values
automatically tracks the object state which is either committed or
discarded depending on whether the state change was committed to hw
or not) which will also be needed for atomic-modeset.
So far, I've only updated omapdrm to the new APIs, as a proof of
concept. Only a few drivers support drm plane, so I expect the
updates to convert drm-plane to properties should not be so hard.
Possibly for crtc/pageflip we might need to have a transition period
where we still support crtc->page_flip() code path until all drivers
are updated.
My complete branch is here:
https://github.com/robclark/kernel-omap4/commits/drm_nuclear
git://github.com/robclark/kernel-omap4.git drm_nuclear
Open points (I think) are:
+ should atomic-pageflip support flips on multiple CRTCs. I think
it at least simplifies things if the driver knows up front which
CRTC(s) are involved, and whether the operation is modeset (sync)
or pageflip (async).
+ How to deal w/ hardware restrictions which span multiple CRTCs.
One idea is to get rid of the test flag in the atomic-pageflip
ioctl, and always do test operations via atomic-modeset ioctl
w/ the test flag.
Rob Clark (11):
drm: add atomic fxns
drm: add object property type
drm: add DRM_MODE_PROP_DYNAMIC property flag
drm: add DRM_MODE_PROP_SIGNED property flag
drm: split property values out
drm: convert plane to properties
drm: add drm_plane_state
drm: convert page_flip to properties
drm: add drm_crtc_state
drm: atomic pageflip
drm/omap: update for atomic age
drivers/gpu/drm/drm_crtc.c | 838 ++++++++++++++++++++++++---------
drivers/gpu/drm/drm_crtc_helper.c | 51 +-
drivers/gpu/drm/drm_drv.c | 1 +
drivers/gpu/drm/drm_fb_helper.c | 11 +-
drivers/staging/omapdrm/Makefile | 1 +
drivers/staging/omapdrm/omap_atomic.c | 339 +++++++++++++
drivers/staging/omapdrm/omap_atomic.h | 52 ++
drivers/staging/omapdrm/omap_crtc.c | 246 +++++-----
drivers/staging/omapdrm/omap_drv.c | 21 +-
drivers/staging/omapdrm/omap_drv.h | 45 +-
drivers/staging/omapdrm/omap_fb.c | 44 +-
drivers/staging/omapdrm/omap_plane.c | 296 ++++++------
include/drm/drm.h | 2 +
include/drm/drmP.h | 52 ++
include/drm/drm_crtc.h | 179 +++++--
include/drm/drm_mode.h | 50 ++
16 files changed, 1607 insertions(+), 621 deletions(-)
create mode 100644 drivers/staging/omapdrm/omap_atomic.c
create mode 100644 drivers/staging/omapdrm/omap_atomic.h
--
1.7.9.5
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