Commit Graph

30 Commits

Author SHA1 Message Date
Daniel Vetter
43968d7b80 drm: Extract drm_plane.[hc]
Just pure code movement, cleanup and polish will happen in later
patches.

v2: Don't forget all the ioctl! To extract those cleanly I decided to
put check_src_coords into drm_framebuffer.c (and give it a
drm_framebuffer_ prefix), since that just checks framebuffer
constraints.

v3: rebase over PAGE_FLIP_TARGET.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

[seanpaul]
This patch as posted on the list was rebased on:

commit 6f00975c61
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Aug 20 12:22:11 2016 +0200

    drm: Reject page_flip for !DRIVER_MODESET

so as a result of moving the page_flip ioctl, this fix has
been rolled into this patch.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
2016-09-22 00:01:56 -07:00
Daniel Vetter
3b24f7d675 drm/atomic: Add struct drm_crtc_commit to track async updates
Split out from my big nonblocking atomic commit helper code as prep
work. While add it, also add some neat asciiart to document how it's
supposed to be used.

v2: Resurrect misplaced hunk in the kerneldoc.

v3: Wording improvements from Liviu.

Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tomeu Vizoso <tomeu.vizoso@gmail.com>
Cc: Daniel Stone <daniels@collabora.com>
Tested-by: Liviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-8-git-send-email-daniel.vetter@ffwll.ch
2016-06-10 16:57:54 +02:00
Daniel Vetter
081e9c0f8b drm/atomic: kerneldoc for drm_atomic_crtc_needs_modeset
Just a bit of drive-by ocd.

v2: Improve per Liviu's feedback.

Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-7-git-send-email-daniel.vetter@ffwll.ch
2016-06-09 10:28:41 +02:00
Daniel Vetter
60c9e19003 drm/atomic-docs: Spelling fixups
Eric nicely pointed these out, but I failed at git add and lost them.
This fixes up

commit 2f196b7c4b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jun 2 16:21:44 2016 +0200

    drm/atomic: Add drm_atomic_crtc_state_for_each_plane_state

to actually do what it says on the tin^Wcommit message.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-06-02 17:41:10 +02:00
Daniel Vetter
5d943aa6c0 drm: Consolidate crtc arrays in drm_atomic_state
It's silly to have 2 mallocs when we could tie these two together.

Also, Gustavo adds another one in his per-crtc out-fence patches. And
I want to add more stuff here for nonblocking commit helpers.

In the future we can use this to store a pointer to the preceeding
state, making an atomic update entirely free-standing. This will be
needed to be able to queue them up with a depth > 1.

Cc: Gustavo Padovan <gustavo@padovan.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464818821-5736-12-git-send-email-daniel.vetter@ffwll.ch
2016-06-02 17:20:32 +02:00
Daniel Vetter
b8b5342b69 drm: Consolidate plane arrays in drm_atomic_state
It's kinda pointless to have 2 separate mallocs for these. And when we
add more per-plane state in the future it's even more pointless.

Right now there's no such thing planned, but both Gustavo's per-crtc
fence patches, and some nonblocking commit helpers I'm playing around
with will add more per-crtc stuff. It makes sense to also consolidate
planes, just for consistency.

In the future we can use this to store a pointer to the preceeding
state, making an atomic update entirely free-standing. This will be
needed to be able to queue them up with a depth > 1.

Cc: Gustavo Padovan <gustavo@padovan.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464818821-5736-11-git-send-email-daniel.vetter@ffwll.ch
2016-06-02 17:20:25 +02:00
Daniel Vetter
63e83c1dba drm: Consolidate connector arrays in drm_atomic_state
It's kinda pointless to have 2 separate mallocs for these. And when we
add more per-connector state in the future it's even more pointless.

Right now there's no such thing planned, but both Gustavo's per-crtc
fence patches, and some nonblocking commit helpers I'm playing around
with will add more per-crtc stuff. It makes sense to also consolidate
connectors, just for consistency.

In the future we can use this to store a pointer to the preceeding
state, making an atomic update entirely free-standing. This will be
needed to be able to queue them up with a depth > 1.

Cc: Gustavo Padovan <gustavo@padovan.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464818821-5736-10-git-send-email-daniel.vetter@ffwll.ch
2016-06-02 17:20:03 +02:00
Daniel Vetter
2f196b7c4b drm/atomic: Add drm_atomic_crtc_state_for_each_plane_state
... and use it in msm&vc4. Again just want to encapsulate
drm_atomic_state internals a bit.

The const threading is a bit awkward in vc4 since C sucks, but I still
think it's worth to enforce this. Eventually I want to make all the
obj->state pointers const too, but that's a lot more work ...

v2: Provide safe macro to wrap up the unsafe helper better, suggested
by Maarten.

v3: Fixup subject (Maarten) and spelling fixes (Eric Engestrom).

Cc: Eric Anholt <eric@anholt.net>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464877304-4213-1-git-send-email-daniel.vetter@ffwll.ch
2016-06-02 16:59:05 +02:00
Maarten Lankhorst
b837ba0ad9 drm/atomic: Rename drm_atomic_async_commit to nonblocking.
Another step in renaming async to nonblocking for atomic commit.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461679905-30177-3-git-send-email-maarten.lankhorst@linux.intel.com
2016-05-02 16:36:03 +02:00
Maarten Lankhorst
14de6c44d1 drm/atomic: Remove drm_atomic_connectors_for_crtc.
Now that connector_mask is reliable there's no need for this
function any more.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451908400-25147-6-git-send-email-maarten.lankhorst@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-06 16:37:39 +01:00
Jani Nikula
373701b1fc drm: fix potential dangling else problems in for_each_ macros
We have serious dangling else bugs waiting to happen in our for_each_
style macros with ifs. Consider, for example,

 #define drm_for_each_plane_mask(plane, dev, plane_mask) \
         list_for_each_entry((plane), &(dev)->mode_config.plane_list, head) \
                 if ((plane_mask) & (1 << drm_plane_index(plane)))

If this is used in context:

	if (condition)
		drm_for_each_plane_mask(plane, dev, plane_mask);
	else
		foo();

foo() will be called for each plane *not* in plane_mask, if condition
holds, and not at all if condition doesn't hold.

Fix this by reversing the conditions in the macros, and adding an else
branch for the "for each" block, so that other if/else blocks can't
interfere. Provide a "for_each_if" helper macro to make it easier to get
this right.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448392916-2281-1-git-send-email-jani.nikula@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-11-25 09:29:21 +01:00
Maarten Lankhorst
0f45c26fc3 drm/atomic: add a drm_atomic_clean_old_fb helper.
This is useful for all the boilerplate code about cleaning old_fb.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-4-git-send-email-maarten.lankhorst@ubuntu.com
2015-11-17 13:02:14 +02:00
Maarten Lankhorst
fc596660dd drm/atomic: add connectors_changed to separate it from mode_changed, v2
This can be a separate case from mode_changed, when connectors stay the
same but only the mode is different. Drivers may choose to implement specific
optimizations to prevent a full modeset for this case.

Changes since v1:
- Update kerneldocs slightly.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-07-27 10:06:38 +02:00
Daniel Vetter
2465ff6217 drm/atomic: Extract needs_modeset function
We use the same check already in the atomic core, so might as well
make this official. And it's also reused in e.g. i915.

Motivated by Maarten's idea to extract a connector_changed state out
of mode_changed.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-By: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-06-19 17:25:01 +02:00
Andrey Ryabinin
60f207a5b6 drm/atomic: fix out of bounds read in for_each_*_in_state helpers
for_each_*_in_state validate array index after
access to array elements, thus perform out of bounds read.

Fix this by validating index in the first place and read
array element iff validation was successful.

Fixes: df63b9994e ("drm/atomic: Add for_each_{connector,crtc,plane}_in_state helper macros")
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-26 17:31:52 +02:00
Daniel Stone
955f3c334f drm/atomic: Add MODE_ID property
Atomic modesetting: now with modesetting support.

v2: Moved drm_atomic_set_mode_prop_for_crtc from previous patch; removed
    state->active fiddling, documented return code. Changed property
    type to DRM_MODE_PROP_BLOB.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Tested-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-26 15:50:42 +02:00
Daniel Stone
819364da20 drm: Add drm_atomic_set_mode_for_crtc
Add a new helper, to be used later for blob property management, that
sets the mode for a CRTC state, as well as updating the CRTC enable/active
state at the same time.

v2: Do not touch active/mode_changed in CRTC state. Document return
    value. Remove stray drm_atomic_set_mode_prop_for_crtc declaration.

v3: Remove i915 changes, and leave it directly bashing crtc_state->mode
    for the meantime.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Tested-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-26 15:50:34 +02:00
Maarten Lankhorst
e01e9f75a0 drm/atomic: add drm_atomic_add_affected_planes
This is a convenience function to add all planes for a crtc,
similar to add_affected_connectors. This will be used in
drm_atomic_helper_check_modeset, but drivers can call it too
when they need to recalculate all state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Amend kerneldoc a bit.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-21 10:29:07 +02:00
Maarten Lankhorst
036ef5733b drm/atomic: Allow drivers to subclass drm_atomic_state, v3
Drivers may need to store the state of shared resources, such as PLLs
or FIFO space, into the atomic state. Allow this by making it possible
to subclass drm_atomic_state.

Changes since v1:
- Change member names for functions to atomic_state_(alloc,clear)
- Change __drm_atomic_state_new to drm_atomic_state_init
- Allow free function to be overridden too, in case extra memory is
  allocated in alloc.
Changes since v2:
- Rename *_default_free to default_release, to make clear it doesn't
  free the state object itself.

Cc: dri-devel@lists.freedesktop.org
Acked-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-18 16:39:41 +02:00
Maarten Lankhorst
1b26a5e193 drm/atomic: add drm_atomic_get_existing_*_state helpers
There are cases where we want to test if a given object is
part of the state, but don't want to add them if they're not.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-13 11:28:22 +02:00
Ander Conselvan de Oliveira
df63b9994e drm/atomic: Add for_each_{connector,crtc,plane}_in_state helper macros
This saves some typing whenever a iteration over all the connector,
crtc or plane states in the atomic state is written, which happens
quite often.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-04-11 18:50:22 +02:00
Daniel Vetter
a97df1ccd3 drm/atomic: Hide drm.ko internal interfaces
This is just a bit fallout from patch polishing and moving the
get_prop logic fully into the core:
- Drop EXPORT_SYMBOL and make the helpers static.
- Drop kerneldoc since not used by drivers.
- Move the cross-file function declarations only used by drm.ko
  internally to an internal header.

v2: keep the gist of the comments, requested by Rob.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-01-05 13:55:30 +01:00
Rob Clark
88a48e297b drm: add atomic properties
Once a driver is using atomic helpers for modeset, the next step is to
switch over to atomic properties.  To do this, make sure that any
modeset objects have their ->atomic_{get,set}_property() vfuncs suitably
populated if they have custom properties (you did already remember to
plug in atomic-helper func for the legacy ->set_property() vfuncs,
right?), and then set DRIVER_ATOMIC bit in driver_features flag.

A new cap is introduced, DRM_CLIENT_CAP_ATOMIC, for the purposes of
shielding legacy userspace from atomic properties.  Mostly for the
benefit of legacy DDX drivers that do silly things like getting/setting
each property at startup (since some of the new atomic properties will
be able to trigger modeset).

Signed-off-by: Rob Clark <robdclark@gmail.com>
[danvet: Squash in fixup patch to check for DRM_MODE_PROP_ATOMIC
instaed of the CAP define when filtering properties. Reported by
Tvrtko Uruslin, acked by Rob.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-01-05 13:54:38 +01:00
Rob Clark
ac9c925616 drm: add atomic_get_property
Since we won't be using the obj->properties->values[] array to shadow
property values for atomic drivers, we are going to need a vfunc for
getting prop values.  Add that along w/ mandatory wrapper fxns.

v2: more comments and copypasta comment typo fix

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-12-18 22:22:46 +01:00
Rob Clark
40ecc694e1 drm: add atomic_set_property wrappers
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: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-12-18 22:22:39 +01:00
Daniel Vetter
07cc0ef67f drm/atomic: Introduce state->obj backpointers
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: Daniel Vetter <daniel.vetter@intel.com>
2014-12-17 20:23:23 +01:00
Rob Clark
6ddd388ab2 drm/atomic: track bitmask of planes attached to crtc
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: Rob 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: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-27 15:38:15 +01:00
Thierry Reding
37cc014877 drm: Make drm_atomic.h standalone includible
This header file makes use of a bunch of structures declared in the
drm_crtc.h header file. Include that to make sure the drm_atomic.h
header can be included standalone.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-25 13:28:25 +01:00
Daniel Vetter
321ebf04dc drm/atomic: Refcounting for plane_state->fb
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: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2014-11-06 21:08:37 +01:00
Daniel Vetter
cc4ceb484b drm: Global atomic state handling
Some differences compared to Rob's patches again:
- Dropped the committed and checked booleans. Checking will be
  internally enforced by always calling ->atomic_check before
  ->atomic_commit. And async handling needs to be solved differently
  because the current scheme completely side-steps ww mutex deadlock
  avoidance (and so either reinvents a new deadlock avoidance wheel or
  like the current code just deadlocks).

- State for connectors needed to be added, since now they have a
  full-blown drm_connector_state (so that drivers have something to
  attach their own stuff to).

- Refcounting is gone. I plane to solve async updates differently,
  since the lock-passing scheme doesn't cut it (since it abuses ww
  mutexes). Essentially what we need for async is a simple ownership
  transfer from the caller to the driver. That doesn't need full-blown
  refcounting.

- The acquire ctx is a pointer. Real atomic callers should have that
  on their stack, legacy entry points need to put the right one
  (obtained by drm_modeset_legacy_acuire_ctx) in there.

- I've dropped all hooks except check/commit. All the begin/end
  handling is done by core functions and is the same.

- commit/check are just thin wrappers that ensure that ->check is
  always called.

- To help out with locking in the legacy implementations I've added a
  helper to just grab all locks in the backoff case.

v2: Add notices that check/commit can fail with EDEADLK.

v3:
- More consistent naming for state_alloc.
- Add state_clear which is needed for backoff and retry.

v4: Planes/connectors can switch between crtcs, and we need to be
careful that we grab the state (and locks) for both the old and new
crtc. Improve the interface functions to ensure this.

v5: Add functions to grab affected connectors for a crtc and to recompute
the crtc->enable state. This is useful for both helper and atomic ioctl
code when e.g. removing a connector.

v6: Squash in fixup from Fengguang to use ERR_CAST.

v7: Add debug output.

v8: Make checkpatch happy about kcalloc argument ordering.

v9: Improve kerneldoc in drm_crtc.h

v10:
- Fix another kcalloc argument misorder I've missed.
- More polish for kerneldoc.

v11: Clarify the ownership rules for the state object. The new rule is
that a successful drm_atomic_commit (whether synchronous or asnyc)
always inherits the state and is responsible for the clean-up. That
way async and sync ->commit functions are more similar.

v12: A few bugfixes:
- Assign state->state pointers correctly when grabbing state objects -
  we need to link them up with the global state.
- Handle a NULL crtc in set_crtc_for_plane to simplify code flow a bit
  for the callers of this function.

v13: Review from Sean:
- kerneldoc spelling fixes
- Don't overallocate states->planes.
- Handle NULL crtc in set_crtc_for_connector.

v14: Sprinkle __must_check over all functions which do wait/wound
locking to make sure callers don't forget this. Since I have ;-)

v15: Be more explicit in the kerneldoc when functions can return
-EDEADLK what to do. And that every other -errno is fatal.

v16: Indent with tabs instead of space, spotted by Ander.

v17: Review from Thierry, small kerneldoc and other naming polish.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-05 18:05:36 +01:00