i915 will soon gain an eviction path that trylock a whole lot of locks
for eviction, getting dmesg failures like below:
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!
48 locks held by i915_selftest/5776:
#0: ffff888101a79240 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x88/0x160
#1: ffffc900009778c0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.63+0x39/0x1b0 [i915]
#2: ffff88800cf74de8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.63+0x5f/0x1b0 [i915]
#3: ffff88810c7f9e38 (&vm->mutex/1){+.+.}-{3:3}, at: i915_vma_pin_ww+0x1c4/0x9d0 [i915]
#4: ffff88810bad5768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
#5: ffff88810bad60e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
...
#46: ffff88811964d768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
#47: ffff88811964e0e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
INFO: lockdep is turned off.
Fixing eviction to nest into ww_class_acquire is a high priority, but
it requires a rework of the entire driver, which can only be done one
step at a time.
As an intermediate solution, add an acquire context to
ww_mutex_trylock, which allows us to do proper nesting annotations on
the trylocks, making the above lockdep splat disappear.
This is also useful in regulator_lock_nested, which may avoid dropping
regulator_nesting_mutex in the uncontended path, so use it there.
TTM may be another user for this, where we could lock a buffer in a
fastpath with list locks held, without dropping all locks we hold.
[peterz: rework actual ww_mutex_trylock() implementations]
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YUBGPdDDjKlxAuXJ@hirez.programming.kicks-ass.net
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Merge tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull rst conversion of docs from Mauro Carvalho Chehab:
"As agreed with Jon, I'm sending this big series directly to you, c/c
him, as this series required a special care, in order to avoid
conflicts with other trees"
* tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (77 commits)
docs: kbuild: fix build with pdf and fix some minor issues
docs: block: fix pdf output
docs: arm: fix a breakage with pdf output
docs: don't use nested tables
docs: gpio: add sysfs interface to the admin-guide
docs: locking: add it to the main index
docs: add some directories to the main documentation index
docs: add SPDX tags to new index files
docs: add a memory-devices subdir to driver-api
docs: phy: place documentation under driver-api
docs: serial: move it to the driver-api
docs: driver-api: add remaining converted dirs to it
docs: driver-api: add xilinx driver API documentation
docs: driver-api: add a series of orphaned documents
docs: admin-guide: add a series of orphaned documents
docs: cgroup-v1: add it to the admin-guide book
docs: aoe: add it to the driver-api book
docs: add some documentation dirs to the driver-api book
docs: driver-model: move it to the driver-api book
docs: lp855x-driver.rst: add it to the driver-api book
...
Convert the locking documents to ReST and add them to the
kernel development book where it belongs.
Most of the stuff here is just to make Sphinx to properly
parse the text file, as they're already in good shape,
not requiring massive changes in order to be parsed.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Federico Vaga <federico.vaga@vaga.pv.it>
The use of the drmP.h header file is deprecated.
Remove use from all files in drm/*
so people do not look there and follow a bad example.
Build tested allyesconfig,allmodconfig on x86, arm etc.
Including alpha that is as always more challenging than
the rest.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20190526173535.32701-8-sam@ravnborg.org
This patch adds a couple of helpers to remove the boilerplate involved
in grabbing all of the modeset locks.
I've also converted the obvious cases in drm core to use the helpers.
The only remaining instance of drm_modeset_lock_all_ctx() is in
drm_framebuffer. It's complicated by the state clear that occurs on
deadlock. ATM, there's no way to inject code in the deadlock path with
the helpers, so it's unfit for conversion.
Changes in v2:
- Relocate ret argument to the end of the list (Daniel)
- Incorporate Daniel's doc suggestions (Daniel)
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20181129150423.239081-4-sean@poorly.run
After we acquired all generic modeset locks in drm_modeset_lock_all, it's
unsafe acquire any other so just mark acquisition as done.
Atomic drivers shouldn't use drm_modeset_lock_all.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180221152331.9212-1-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Harry Wentland <harry.wentland@amd.com>
To acquire all modeset locks requires a ww_ctx to be allocated. As this
is the legacy path and the allocation small, to reduce the changes
required (and complex untested error handling) to the legacy drivers, we
simply assume that the allocation succeeds. At present, it relies on the
too-small-to-fail rule, but syzbot found that by injecting a failure
here we would hit the WARN. Document that this allocation must succeed
with __GFP_NOFAIL.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031115535.15166-1-chris@chris-wilson.co.uk
When we want to make drm_atomic_commit interruptible, there are a lot of
places that call the lock function, which we don't have control over.
Rather than trying to convert every single one, it's easier to toggle
interruptible waiting per acquire_ctx. If drm_modeset_acquire_init is
called with DRM_MODESET_ACQUIRE_INTERRUPTIBLE, then we will perform
interruptible waits in drm_modeset_lock and drm_modeset_backoff.
Changes since v1:
- Fix locking example in drm_modeset_lock.c to be compatible
with interruptible waiting (xexaxo) and make it default.
Uninterruptible waiting shouldn't happen except in corner cases,
but the example will still apply if the flag is removed.
- Add drm_modeset_lock_single_interruptible() to documentation.
- Fix dead link to removed drm_modeset_lock_interruptible() in
drm_modeset_lock().
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-2-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Explain better when the drm_modeset_acquire_ctx parameter can
be skipped for drm_modeset_lock() call.
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170720160748.12856-1-Liviu.Dudau@arm.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
With all the callers of drm_modeset_lock_crtc gone, and all the places
it was formerly used properly wiring the acquire ctx through, we can
remove this.
The only hidden context magic we still have is now the global one.
Reviewed-by: Harry Wentland <harry.wentland@amd.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/20170403083304.9083-4-daniel.vetter@ffwll.ch
The last user, the cursor ioctl, can just open-code this too. We
simply have to move the acquire ctx dance from the universal function
up into the top-level ioctl handler.
Reviewed-by: Harry Wentland <harry.wentland@amd.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/20170403083304.9083-3-daniel.vetter@ffwll.ch
This is only for legacy paths that need to grab the crtc/plane lock
combo. If you want to lock a crtc, just use drm_modeset_lock().
Reviewed-by: Harry Wentland <harry.wentland@amd.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/20170403083304.9083-2-daniel.vetter@ffwll.ch
I just learned that &struct_name.member_name works and looks pretty
even. It doesn't (yet) link to the member directly though, which would
be really good for big structures or vfunc tables (where the
per-member kerneldoc tends to be long).
Also some minor drive-by polish where it makes sense, I read a lot
of docs ...
v2: Review from Eric.
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170125062657.19270-4-daniel.vetter@ffwll.ch
kbuild spotted this error, with drm/msm patches that add a new
modeset-lock in the driver and driver built as a module:
ERROR: "crtc_ww_class" [drivers/gpu/drm/msm/msm.ko] undefined!
Really the only reason for crtc_ww_class not being internal to
drm_modeset_lock.c is that drm_modeset_lock_init() was static-inline
(for no particularly good reason).
Fix that, and move crtc_ww_class into drm_modeset_lock.c.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1479163257-18703-1-git-send-email-robdclark@gmail.com
Just fallout from switching from asciidoc to sphinx/rst.
v2: Found more. Also s/\//#/ in the vgpu ascii-art - sphinx treats
those as comments and switch to variable-width, which wreaks the
layout.
v3: Undo some of the hacks, rebasing onto latest version of Jani's
series fixed it.
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
DRM Docbook is now Markdown ready. This means its doc is able to
use markdown text on it.
* Documentation/DocBook/drm.tmpl: Contains a table duplicated from
drivers/gpu/drm/i915/i915_reg.h. This is not needed anymore
* drivers/gpu/drm/drm_modeset_lock.c: had a code example that used
to look pretty bad on html. Fixed by using proper code markup.
* drivers/gpu/drm/drm_prime.c: Remove spaces between lines to make
a proper markup list.
* drivers/gpu/drm/i915/i915_reg.h: Altought pandoc supports tables,
it doesn't support table cell spanning. But we can use fixed-width
for those special cases.
* include/drm/drm_vma_manager.h: Another code example that should be
proper indented with four spaces.
v2 (Daniel): Adjust name to gpu.xml due to rename.
v3 (Daniel):
Split out the actual enabling in the Makefile - this way we can merge
the conversion, while just keeping the enabling in a drm-private tree.
Signed-off-by: Danilo Cesar Lemes de Paula <danilo.cesar@collabora.co.uk> (v1)
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kernel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448471279-19748-2-git-send-email-daniel.vetter@ffwll.ch
This function is like drm_modeset_lock_all(), but it takes the lock
acquisition context as a parameter rather than storing it in the DRM
device's mode_config structure.
Implement drm_modeset_{,un}lock_all() in terms of the new function for
better code reuse, and add a note to the kerneldoc that new code should
use the new functions.
v2: improve kerneldoc
v4: rename drm_modeset_lock_all_crtcs() to drm_modeset_lock_all_ctx()
and take mode_config's .connection_mutex instead of .mutex lock to
avoid lock inversion (Daniel Vetter), use drm_modeset_drop_locks()
which is now the equivalent of drm_modeset_unlock_all_ctx()
v5: do not take the dev->mode_config.connection_mutex in
drm_atomic_legacy_backoff() since drm_modeset_lock_all_ctx()
already keeps it, enhance kerneldoc for drm_modeset_lock_all_ctx()
(Daniel Vetter)
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449075005-13937-1-git-send-email-thierry.reding@gmail.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This will make sure we get a lockdep spat in all cases
even if the context is a complete garbage pointer.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The last user is gone, no need for trylocking any more in this legacy
helper.
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Remaining manual work in the drm core&helpers. Nothing special here,
no surprises.
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Need to free just allocated ctx allocation if we cannot
get our config mutex.
This one has been flagged by kbuild bot all the way back in August,
but somehow nobody picked it up:
https://lists.01.org/pipermail/kbuild/2014-August/001691.html
In addition there is another failure path that leaks the same
ctx reference that is fixed.
Found with smatch.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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 d0fa1af40e
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 21e88620aa
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: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Pull drm updates from Dave Airlie:
"This is the main git pull for the drm,
I pretty much froze major pulls at -rc5/6 time, and haven't had much
fallout, so will probably continue doing that.
Lots of changes all over, big internal header cleanup to make it clear
drm features are legacy things and what are things that modern KMS
drivers should be using. Also big move to use the new generic fences
in all the TTM drivers.
core:
atomic prep work,
vblank rework changes, allows immediate vblank disables
major header reworking and cleanups to better delinate legacy
interfaces from what KMS drivers should be using.
cursor planes locking fixes
ttm:
move to generic fences (affects all TTM drivers)
ppc64 caching fixes
radeon:
userptr support,
uvd for old asics,
reset rework for fence changes
better buffer placement changes,
dpm feature enablement
hdmi audio support fixes
intel:
Cherryview work,
180 degree rotation,
skylake prep work,
execlist command submission
full ppgtt prep work
cursor improvements
edid caching,
vdd handling improvements
nouveau:
fence reworking
kepler memory clock work
gt21x clock work
fan control improvements
hdmi infoframe fixes
DP audio
ast:
ppc64 fixes
caching fix
rcar:
rcar-du DT support
ipuv3:
prep work for capture support
msm:
LVDS support for mdp4, new panel, gpu refactoring
exynos:
exynos3250 SoC support, drop bad mmap interface,
mipi dsi changes, and component match support"
* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (640 commits)
drm/mst: rework payload table allocation to conform better.
drm/ast: Fix HW cursor image
drm/radeon/kv: add uvd/vce info to dpm debugfs output
drm/radeon/ci: add uvd/vce info to dpm debugfs output
drm/radeon: export reservation_object from dmabuf to ttm
drm/radeon: cope with foreign fences inside the reservation object
drm/radeon: cope with foreign fences inside display
drm/core: use helper to check driver features
drm/radeon/cik: write gfx ucode version to ucode addr reg
drm/radeon/si: print full CS when we hit a packet 0
drm/radeon: remove unecessary includes
drm/radeon/combios: declare legacy_connector_convert as static
drm/radeon/atombios: declare connector convert tables as static
drm/radeon: drop btc_get_max_clock_from_voltage_dependency_table
drm/radeon/dpm: drop clk/voltage dependency filters for BTC
drm/radeon/dpm: drop clk/voltage dependency filters for CI
drm/radeon/dpm: drop clk/voltage dependency filters for SI
drm/radeon/dpm: drop clk/voltage dependency filters for NI
drm/radeon: disable audio when we disable hdmi (v2)
drm/radeon: split audio enable between eg and r600 (v2)
...
Bunch of small leftovers spotted by looking at the make htmldocs output.
I've left out dp mst, there's too much amiss there.
v2: Also add the missing parameter docbook in the dp mst code - Dave
Airlie correctly pointed out that we don't actually want kerneldoc for
the missing structure members in header files.
Cc: Dave Airlie <airlied@gmail.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
In the fbdev code we want to do trylocks only to avoid deadlocks and
other ugly issues. Thus far we've only grabbed the overall modeset
lock, but that already failed to exclude a pile of potential
concurrent operations. With proper atomic support this will be worse.
So add a trylock mode to the modeset locking code which attempts all
locks only with trylocks, if possible. We need to track this in the
locking functions themselves and can't restrict this to drivers since
driver-private w/w mutexes must be treated the same way.
There's still the issue that other driver private locks aren't handled
here at all, but well can't have everything. With this we will at
least not regress, even once atomic allows lots of concurrent kms
activity.
Aside: We should move the acquire context to stack-based allocation in
the callers to get rid of that awful WARN_ON(kmalloc_failed) control
flow which just blows up when memory is short. But that's material for
separate patches.
v2:
- Fix logic inversion fumble in the fb helper.
- Add proper kerneldoc.
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
So drivers using the atomic interfaces expect that they can acquire
additional locks internal to the driver as-needed. Examples would be
locks to protect shared state like shared display PLLs.
Unfortunately the legacy ioctls assume that all locking is fully done
by the drm core. Now for those paths which grab all locks we already
have to keep around an acquire context in dev->mode_config. Helper
functions that implement legacy interfaces in terms of atomic support
can therefore grab this acquire contexts and reuse it.
The only interfaces left are the cursor and pageflip ioctls. So add
functions to grab the crtc lock these need using an acquire context
and preserve it for atomic drivers to reuse.
v2:
- Fixup comments&kerneldoc.
- Drop the WARNING from modeset_lock_all_crtcs since that can be used
in legacy paths with crtc locking.
v3: Fix a type on the kerneldoc Dave spotted.
Cc: Dave Airlie <airlied@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Somehow we've forgotten about this little bit of OCD.
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The acquire ctx will typically be declared on the stack, which means we
could have garbage values for any uninitialized field. In this case, it
was triggering WARN_ON()s because 'contended' had garbage value.
Go ahead and use memset() to be more future-proof.
v2: now with extra brown paper bag
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
For atomic, it will be quite necessary to not need to care so much
about locking order. And 'state' gives us a convenient place to stash a
ww_ctx for any sort of update that needs to grab multiple crtc locks.
Because we will want to eventually make locking even more fine grained
(giving locks to planes, connectors, etc), split out drm_modeset_lock
and drm_modeset_acquire_ctx to track acquired locks.
Atomic will use this to keep track of which locks have been acquired
in a transaction.
v1: original
v2: remove a few things not needed until atomic, for now
v3: update for v3 of connection_mutex patch..
v4: squash in docbook
v5: doc tweaks/fixes
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
