Use cases like rotation require these hooks to have some context so they
know how to prepare and cleanup the frame buffer correctly.

For i915 specifically, object backing pages need to be mapped differently
for different rotation modes and the driver needs to know which mapping to
instantiate and which to tear down when transitioning between them.

v2: Made passed in states const. (Daniel Vetter)

[airlied: add mdp5 and atmel fixups]
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

With runtime PM the hw might still be off while doing the ->mode_set
callbacks - runtime PM get/put should only happen in the
enable/disable hooks to properly support DPMS. Which essentially makes
these callbacks useless for drivers support runtime PM, so make them
optional. Again motivated by discussions with Laurent.

Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

These names only make sense because of backwards compatability with
the order used by the crtc helper library. There's not really any real
requirement in the ordering here.

So rename them to something more descriptive and update the kerneldoc
a bit. Motivated in a discussion with Laurent about how to restore
plane state for dpms for drivers with runtime pm.

v2: Squash in fixup from Stephen Rothwell to fix a conflict with
tegra.

Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Acked-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The argument contains a pointer to the old state, rename it to old_state
like in all other commit helper functions.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Atomic state handling adds a lot of indirection and complexity between
simple updates and drivers. For easier debugging the diagnostic output
is therefore rather chatty. Which is great for tracking down atomic
issues, but really annoying otherwise.

Add a new DRM_DEBUG_ATOMIC to be able to filter this out.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The kerneldoc blocks for the drm_atomic_helper_*_set_property()
functions seem to have been copied from the plane disable handler
without being properly updated. Fix them.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This callback can be used instead of the legacy ->mode_fixup() and is
passed the CRTC and connector states. It can thus use these states to
validate the modeset and cache values in the state to be used during
the actual modeset.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NThierry Reding <treding@nvidia.com>

In order to prevent drivers from having to perform the same checks over
and over again, add an optional ->atomic_disable callback which the core
calls under the right circumstances.

v2: pass old state and detect edges to avoid calling ->atomic_disable on
already disabled planes, remove redundant comment (Daniel Vetter)

v3: rename helper to drm_atomic_plane_disabling() to clarify that it is
checking for transitions, move helper to drm_atomic_helper.h, clarify
check for !old_state and its relation to transitional helpers

Here's an extract from some discussion rationalizing the behaviour (for
a full version, see the reference below):

    > > Hm, thinking about this some more this will result in a slight difference
    > > in behaviour, at least when drivers just use the helper ->reset functions
    > > but don't disable everything:
    > > - With transitional helpers we assume we know nothing and call
    > >   ->atomic_disable.
    > > - With atomic old_state->crtc == NULL in the same situation right after
    > >   boot-up, but we asssume the plane is really off and _dont_ call
    > >   ->atomic_disable.
    > >
    > > Should we instead check for (old_state && old_state->crtc) and state that
    > > drivers need to make sure they don't have stuff hanging around?
    >
    > I don't think we can check for old_state because otherwise this will
    > always return false, whereas we really want it to force-disable planes
    > that could be on (lacking any more accurate information). For
    > transitional helpers anyway.
    >
    > For the atomic helpers, old_state will never be NULL, but I'd assume
    > that the driver would reconstruct the current state in ->reset().

    By the way, the reason for why old_state can be NULL with transitional
    helpers is the ordering of the steps in the atomic transition. Currently
    the Tegra patches do this (based on your blog post and the Exynos proto-
    type):

        1) atomic conversion, phase 1:
           - implement ->atomic_{check,update,disable}()
           - use drm_plane_helper_{update,disable}()

        2) atomic conversion, phase 2:
           - call drm_mode_config_reset() from ->load()
           - implement ->reset()

    That's only a partial list of what's done in these steps, but that's the
    only relevant pieces for why old_state is NULL.

    What happens is that without ->reset() implemented there won't be any
    initial state, hence plane->state (the old_state here) will be NULL the
    first time atomic state is applied.

    We could of course reorder the sequence such that drivers are required
    to hook up ->reset() before they can (or at the same as they) hook up
    the transitional helpers. We could add an appropriate WARN_ON to this
    helper to make that more obvious.

    However, that will not solve the problem because it only gets rid of the
    special case. We still don't know whether old_state->crtc == NULL is the
    current state or just the initial default.

    So no matter which way we do this, I don't see a way to get away without
    requiring specific semantics from drivers. They would be that:

        - drivers recreate the correct state in ->reset() so that
          old_state->crtc != NULL if the plane is really enabled

    or

        - drivers have to ensure that the real state in fact mirrors the
          initial default as encoded in the state (plane disabled)

References: http://lists.freedesktop.org/archives/dri-devel/2015-January/075578.htmlReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NThierry Reding <treding@nvidia.com>

There is no use-case where it would be useful for drivers not to
implement this function and the transitional plane helpers already
require drivers to provide an implementation.

v2: add new requirement to kerneldoc
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NThierry Reding <treding@nvidia.com>

With the combination of ->enable and ->active it's a bit complicated
to follow what exactly is going on sometimes within a full modeset.
Add debug output to make this all traceable.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

For historical reasons going all the way back to how the Xrandr code
was implemented the semantics of the callbacks used to enable/disable
crtcs and encoders are ... interesting.

But with atomic helpers all that complexity has been binned, with only
a well-defined on/off action left. Unfortunately the names stuck.

Let's fix that by adding enable/disable hooks every, make them the
preferred variant for atomic and update documentations.

Later on we add debug warnings when drivers have deprecated hooks. But
while everything is in-flight with lots of drivers converting to
atomic that's a bit too much - better wait for things to settle a bit
first.

v2: Fix kerneldoc, reported by Wu Fengguang.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Cursor plane updates have historically been fully async and mutliple
updates batched together for the next vsync. And userspace relies upon
that. Since implementing a full queue of async atomic updates is a bit
of work lets just recover the cursor specific behaviour with a hint
flag and some hacks to drop the vblank wait.

v2: Fix kerneldoc, reported by Wu Fengguang.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This builds on top of the crtc->active infrastructure to implement
legacy DPMS. My choice of semantics is somewhat arbitrary, but the
entire pipe is enabled as along as one output is still enabled.

Of course it also clamps everything that's not ON to OFF.

v2: Fix spelling in one comment.

v3: Don't do an async commit (Thierry)

v4: Dan Carpenter noticed missing error case handling.

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Tested-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This is the infrastructure for DPMS ported to the atomic world.
Fundamental changes compare to legacy DPMS are:

- No more per-connector dpms state, instead there's just one per each
  display pipeline. So if you clone either you have to unclone first
  if you only want to switch off one screen, or you just switch of
  everything (like all desktops do). This massively reduces complexity
  for cloning since now there's no more half-enabled cloned configs to
  consider.

- Only on/off, dpms standby/suspend are as dead as real CRTs. Again
  reduces complexity a lot.

Now especially for backwards compat the really important part for dpms
support is that dpms on always succeeds (except for hw death and
unplugged cables ofc). Which means everything that could fail (like
configuration checking, resources assignments and buffer management)
must be done irrespective from ->active. ->active is really only a
toggle to change the hardware state. More precisely:

- Drivers MUST NOT look at ->active in their ->atomic_check callbacks.
  Changes to ->active MUST always suceed if nothing else changes.

- Drivers using the atomic helpers MUST NOT look at ->active anywhere,
  period. The helpers will take care of calling the respective
  enable/modeset/disable hooks as necessary. As before the helpers
  will carefully keep track of the state and not call any hooks
  unecessarily, so still no double-disables or enables like with crtc
  helpers.

- ->mode_set hooks are only called when the mode or output
  configuration changes, not for changes in ->active state.

- Drivers which reconstruct the state objects in their ->reset hooks
  or through some other hw state readout infrastructure must ensure
  that ->active reflects actual hw state.

This just implements the core bits and helper logic, a subsequent
patch will implement the helper code to implement legacy dpms with
this.

v2: Rebase on top of the drm ioctl work:
- Move crtc checks to the core check function.
- Also check for ->active_changed when deciding whether a modeset
  might happen (for the ALLOW_MODESET mode).
- Expose the ->active state with an atomic prop.

v3: Review from Rob
- Spelling fix in comment.
- Extract needs_modeset helper to consolidate the ->mode_changed ||
  ->active_changed checks.

v4: Fixup fumble between crtc->state and crtc_state.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Tested-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Add functions to check core plane/crtc state.

v2: comments, int-overflow checks, call from core rather than
    helpers to be sure drivers can't find a way to bypass core
    checks
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As we add properties for all the standard plane/crtc/connector
attributes (in preperation for the atomic ioctl), we are going to want
to handle core state in core (rather than per driver).  Intercepting the
core properties will be easier if the atomic_set_property vfuncs are not
called directly, but instead have a mandatory wrapper function (which
will later serve as the point to intercept core properties).

v2: more verbose comments and copypasta comment fix
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Useful since this way we can pass around just the state objects and
will get ther real object, too.

Specifically this allows us to again simplify the parameters for
set_crtc_for_plane.

v2: msm already has it's own specific plane_reset hook, don't forget
that one!

v3: Fixup kerneldoc, reported by 0-day builder.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com> (v2)
Tested-by: Rob Clark <robdclark@gmail.com> (v2)
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This essentially reverts

commit 934ce1c2
Author: Rob Clark <robdclark@gmail.com>
Date:   Wed Nov 19 16:41:33 2014 -0500

    drm/atomic: check mode_changed *after* atomic_check

Depending upon the driver both orders (or maybe even interleaving) is
required:
- If ->atomic_check updates ->mode_changed then helper_check_modeset
  must be run afters.
- If ->atomic_check depends upon accurate adjusted dotclock values for
  e.g. watermarks, then helper_check_modeset must be run first.

The failure mode in the first case is usually a totally angry hw
because the pixel format switching doesn't happen. The failure mode in
the later case is usually nothing, since in most cases the old
adjusted mode from the previous modeset wont be too far off to be a
problem. So just underruns and perhaps even just suboptimal (from a
power consumption) watermarks.

Furthermore in the transitional helpers we only call ->atomic_check
after the new modeset state has been fully set up (and hence
computed).

Given that asymmetry in expected failure modes I think it's safer to
go back to the older order. So do that and give msm a special check
function to compensate.

Also update kerneldoc to explain this a bit.

v2: Actually add the missing hunk Rob spotted.

v3: Move msm_atomic_check into msm_atomic.c, requested by Rob.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Tested-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The default call sequence for these two parts won't fit for all
drivers. So export the two pieces and explain with a bit of kerneldoc
when each should be called.

v2: Squash in fixup from Rob to actually add the newly exported
functions to headers

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

When a plane is being enabled, plane->crtc has not been set yet.  Use
plane->state->crtc.
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise we'd still end up w/ the plane attached to the CRTC, and
seemingly active, but without an FB.  Which ends up going *boom*
in the drivers.

Slightly modified version of Daniel's irc suggestion.

Note that the big problem isn't drivers going *boom* here (since we
already have the situation of planes being left enabled when the crtc
goes down). The real issue is that the core assumes the primary plane
always goes down when calling ->set_config with a NULL mode. Ignoring
that assumption leads to the legacy state pointers plane->fb/crtc
getting out of sync with atomic, and that then leads to the subsequent
*boom* all over the place.

CC: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NRob Clark <robdclark@gmail.com>
[danvet: Drop my opinion of what's going sidewides here into the
commit message as a note.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Chasing plane->state->crtc of planes that are *not* part of the same
atomic update is racy, making it incredibly awkward (or impossible) to
do something simple like iterate over all planes and figure out which
ones are attached to a crtc.

Solve this by adding a bitmask of currently attached planes in the
crtc-state.

Note that the transitional helpers do not maintain the plane_mask.  But
they only support the legacy ioctls, which have sufficient brute-force
locking around plane updates that they can continue to loop over all
planes to see what is attached to a crtc the old way.
Signed-off-by: NRob Clark <robdclark@gmail.com>
[danvet:
- Drop comments about locking in set_crtc_for_plane since they're a
  bit misleading - we already should hold lock for the current crtc.
- Also WARN_ON if get_state on the old crtc fails since that should
  have been done already.
- Squash in fixup to check get_plane_state return value, reported by
  Dan Carpenter and acked by Rob Clark.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In most situations it will be useful to have the old state passed to the
->atomic_update() callback. For example if a plane is being disabled the
new state's .crtc field will be NULL, but some drivers may rely on this
field to program the CRTCs registers.

v2: rename variable to old_plane_state and remove redundant comment as
suggested by Daniel Vetter, remove an Exynos hunk that doesn't apply to
drm-next and add a hunk for pending MSM mdp5 changes
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The drm core can call the plane disable hook multiple times, which
means it can get called when plane->crtc is already NULL. That in turn
means we can't get at the implicit acquire ctx we use in the atomic
helpers for legacy entries points.

We could try to pass drm_modeset_legacy_acquire_ctx a drm_device
pointer so that it can cope with a NULL crtc. But that still doesn't
work since the cursor ioctls (remapped with the universal cursor plane
support code) only grabs the crtc locks. So the global acquire context
isn't set eitehr.

The real solution here would be to bite the bullet and wire up
explicit acquire context parameters to all relevant functions. We need
to do that anyway (to be able to get rid of some small allocations
which we can't cope with failing). But that's a lot of work and better
done once atomic has settled a bit.

So meanwhile just catch this case in the helper and bail out.
Signed-off-by: NJasper St. Pierre <jstpierre@mecheye.net>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Completely rewrite commit message and comment but keep
Jasper's logic and author credits since his patch is the only
short-term solution that works.]
Tested-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Especially with legacy cursor ioctls existing userspace assumes that
you can pile up lots of updates in one go. The super-proper way to
support this would be a special commit mode which overwrites the last
update. But getting there will be quite a bit of work.

Meanwhile do what pretty much all the drivers have done for the plane
update functions: Simply skip the vblank wait for the buffer cleanup
if the buffer is the same. Since the universal cursor plane code will
not recreate framebuffers needlessly this allows us to not slow down
legacy pageflip events while someone moves the cursor around.

v2: Drop the async plane update hunk from a previous attempt at this
issue.

v3: Fix up kerneldoc.

v4: Don't oops so badly. Reported by Jasper.

Cc: Rob Clark <robdclark@gmail.com>
Cc: "Jasper St. Pierre" <jstpierre@mecheye.net>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NJasper St. Pierre <jstpierre@mecheye.net>
Tested-by: NJasper St. Pierre <jstpierre@mecheye.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

In disable_outputs() we need to shut down the outgoing encoder, not the
incoming one (we have already swapped-state at this point).  Without
this, we end up telling the driver to crtc->dpms(OFF) without first
encoder->dpms(OFF), and that makes some hw quite unhappy.

v2: missing WARN_ON() hunk and comment
Reviewed-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NRob Clark <robdclark@gmail.com>

The intention is that drivers can set crtc_state->mode_changed in their
atomic_check() fxns if they encounter a scenario that requires full
modeset.
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Oversight from my kerneldoc cleanup when doing the original atomic
helper series - I've only applied this clarification to the modeset
related helpers, and not the plane update code. Remedy this asap.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Yet another fallout from not considering DP MST hotplug. With the
previous patches we have stable indices, but it might still happen
that a connector gets added between when we allocate the array and
when we actually add a connector. Especially when we back off due to
ww mutex contention or similar issues.

So store the sizes of the arrays in struct drm_atomic_state and double
check them. We don't really care about races except that we want to
use a consistent value, so ACCESS_ONCE is all we need. And if we
indeed notice that we'd overrun the array then just give up and
restart the entire ioctl.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Otherwise the connector might have been unplugged and destroyed while
we didn't look. Yet another fallout from DP MST hotplugging that I
didn't consider.

To make sure we get this right add an appropriate WARN_ON to
drm_atomic_state_clear (obviously only when we actually have a state
to clear up). And reorder all the state_clear and backoff calls to
make it work out properly.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

For async commit, it is *intentional* that those locks are not held.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Turned out to be much simpler on top of my latest atomic stuff than
what I've feared. Some details:

- Drop the modeset_lock_all snakeoil in drm_plane_init. Same
  justification as for the equivalent change in drm_crtc_init done in

	commit d0fa1af4
	Author: Daniel Vetter <daniel.vetter@ffwll.ch>
	Date:   Mon Sep 8 09:02:49 2014 +0200

	    drm: Drop modeset locking from crtc init function

  Without these the drm_modeset_lock_init would fall over the exact
  same way.

- Since the atomic core code wraps the locking switching it to
  per-plane locks was a one-line change.

- For the legacy ioctls add a plane argument to the locking helper so
  that we can grab the right plane lock (cursor or primary). Since the
  universal cursor plane might not be there, or someone really crazy
  might forgoe the primary plane even accept NULL.

- Add some locking WARN_ON to the atomic helpers for good paranoid
  measure and to check that it all works out.

Tested on my exynos atomic hackfest with full lockdep checks and ww
backoff injection.

v2: I've forgotten about the load-detect code in i915.

v3: Thierry reported that in latest 3.18-rc vmwgfx doesn't compile any
more due to

commit 21e88620
Author: Rob Clark <robdclark@gmail.com>
Date:   Thu Oct 30 13:39:04 2014 -0400

    drm/vmwgfx: fix lock breakage

Rebased and fix this up.

Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

v1: original
v2: danvet's kerneldoc nitpicks
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

So my original plan was that the drm core refcounts framebuffers like
with the legacy ioctls. But that doesn't work for a bunch of reasons:

- State objects might live longer than until the next fb change
  happens for a plane. For example delayed cleanup work only happens
  _after_ the pageflip ioctl has completed. So this definitely doesn't
  work without the plane state holding its own references.

- The other issue is transition from legacy to atomic implementations,
  where the driver works under a mix of both worlds. Which means
  legacy paths might not properly update the ->fb pointer under
  plane->state->fb. Which is a bit a problem when then someone comes
  around and _does_ try to clean it up when it's long gone.

The second issue is just a bit a transition bug, since drivers should
update plane->state->fb in all the paths that aren't converted yet.
But a bit more robustness for the transition can't hurt - we pull
similar tricks with cleaning up the old fb in the transitional helpers
already.

The pattern for drivers that transition is

	if (plane->state)
		drm_atomic_set_fb_for_plane(plane->state, plane->fb);

inserted after the fb update has logically completed at the end of
->set_config (or ->set_base/mode_set if using the crtc helpers),
->page_flip, ->update_plane or any other entry point which updates
plane->fb.

v2: Update kerneldoc - copypasta fail.

v3: Fix spelling in the commit message (Sean).
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

In all cases the text requires that new drivers are converted to the
atomic interfaces.

v2: Add overview for state handling.

v3: Review from Sean: Some spelling fixes and drop the misguided
hunk to remove rgba8888 from the plane helpers compat list.

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The atomic users and helpers assume that there is always a obj->state
structure around. Which means drivers need to somehow create that at
driver load time. Also it should obviously reset hardware state, so
needs to be reset upon resume.

Finally the destroy/duplicate_state functions are an awful lot of
boilerplate if the driver doesn't need anything beyond the default
state objects.

So add helper functions for all of this.

v2: Somehow the plane/connector versions got lost in the first
version.

v3: Add kerneldoc.

v4: Make duplicate_state functions a bit more robust, which is useful
for debugging state tracking issues when transitioning to atomic.

v5: Clear temporary variables in the crtc state when duplicating it,
like ->mode_changed or ->planes_changed. If we don't do this stale
values for these might pollute the next atomic modeset.

v6: Also clear crtc_state->event in case the driver didn't (yet) clear
this out.

v7: Split out wrong squashed commit. Also improve the kerneldoc to
mention that obj->state can be NULL and when.  Both suggested by
Daniel Thompson.

Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently there is no way to implement async flips using atomic, that
essentially requires us to be able to cancel pending requests
mid-flight.

To be able to do that (and I guess we want this since vblank synced
updates which opportunistically cancel still pending updates seem to be
wanted) we'd need to add a mandatory cancellation mode. Depending upon
the exact semantics we decide upon that could mean that userspace will
not get completion events, or will get them all stacked up.

So reject async updates for now. Also async updates usually means not
vblank synced at all, and I guess for drivers which want to support
this they should simply add a special pageflip handler (since usually
you need a special flip cmd to achieve this). That kind of async flip
is pretty much exclusively just used for games and benchmarks where
dropping just one frame means you'll get a headshot or something bad
like that ... And so slight amounts of tearing is acceptable.

v2: Fixup kerneldoc, reported by Paulo.

v3: Use the set_crtc_for_plane function to assign the crtc, since
otherwise the book-keeping is off.

v4: Update crtc->primary->fb since ->page_flip is the only driver
callback where the core won't do this itself. We might want to fix
this inconsistency eventually.

v5: Use set_crtc_for_connector as suggested by Sean.

v6: Daniel Thompson noticed that my error handling is inconsistent
and that in a few cases I didn't handle fatal errors (i.e. not
-EDEADLK). Fix this by consolidate the ww mutex backoff handling
into one check in the fail: block and flatten the error control
flow everywhere else.

v7: Fix spelling mistake in the commit message (Sean).

Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No helper function to do it all yet provided since no driver has
support for driver core fences yet. Which we'd need to make the
implementation really generic.

v2: Clarify async howto a bit per the discussion With Rob Clark.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is for enabling async commits. It replaces an earlier
approach which added an async boolean paramter to the ->prepare_fb
callbacks. The idea is that prepare_fb picks up the right fence to
synchronize against, which is then used by the synchronous commit
helper. For async commits drivers can either register a callback to
the fence or simply do the synchronous wait in their async work queue.

v2: Remove unused variable.

v3: Only wait for fences after the point of no return in the part
of the commit function which can be run asynchronously. This is after
the atomic state has been swapped in, hence now check
plane->state->fence.

Also add a WARN_ON to make sure we don't try to wait on a fence when
there's no fb, just as a sanity check.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Well, except page_flip since that requires async commit, which isn't
there yet.

For the functions which changes planes there's a bit of trickery
involved to keep the fb refcounting working. But otherwise fairly
straight-forward atomic updates.

The property setting functions are still a bit incomplete. Once we
have generic properties (e.g. rotation, but also all the properties
needed by the atomic ioctl) we need to filter those out and parse them
in the helper. Preferrably with the same function as used by the real
atomic ioctl implementation.

v2: Fixup kerneldoc, reported by Paulo.

v3: Add missing EXPORT_SYMBOL.

v4: We need to look at the crtc of the modeset, not some random
leftover one from a previous loop when udpating the connector->crtc
routing. Also push some local variables into inner loops to avoid
these kinds of bugs.

v5: Adjust semantics - drivers now own the atomic state upon
successfully synchronous commit.

v6: Use the set_crtc_for_plane function to assign the crtc, since
otherwise the book-keeping is off.

v7:
- Improve comments.
- Filter out the crtc of the ->set_config call when recomputing
  crtc_state->enabled: We should compute the same state, but not doing
  so will give us a good chance to catch bugs and inconsistencies -
  the atomic helper's atomic_check function re-validates this again.
- Fix the set_config implementation logic when disabling the crtc: We
  still need to update the output routing to disable all the
  connectors properly in the state. Caught by the atomic_check
  functions, so at least that part worked ;-) Also add some WARN_ONs
  to ensure ->set_config preconditions all apply.

v8: Fixup an embarrassing h/vdisplay mixup.

v9: Shuffled bad squash to the right patch, spotted by Daniel

v10: Use set_crtc_for_connector as suggested by Sean.

v11: Daniel Thompson noticed that my error handling is inconsistent
and that in a few cases I didn't handle fatal errors (i.e. not
-EDEADLK). Fix this by consolidate the ww mutex backoff handling
into one check in the fail: block and flatten the error control
flow everywhere else.

v12: Review and discussion with Sean:
- One spelling fix.
- Correctly skip the crtc from the set_config set when recomputing
  ->enable state. That should allow us to catch any bugs in higher
  levels in computing that state (which is supplied to the
  ->set_config implementation). I've screwed this up and Sean spotted
  that the current code is pointless.

Cc: Sean Paul <seanpaul@chromium.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>