Pull drm updates from Dave Airlie:
"This is the main drm pull request for 4.14 merge window.
I'm sending this early, as my continuing journey into fatherhood is
occurring really soon now, I'm going to be mostly useless for the next
couple of weeks, though I may be able to read email, I doubt I'll be
doing much patch applications or git sending. If anything urgent pops
up I've asked Daniel/Jani/Alex/Sean to try and direct stuff towards
you.
Outside drm changes:
Some rcar-du updates that touch the V4L tree, all acks should be in
place. It adds one export to the radix tree code for new i915 use
case. There are some minor AGP cleanups (don't see that too often).
Changes to the vbox driver in staging to avoid breaking compilation.
Summary:
core:
- Atomic helper fixes
- Atomic UAPI fixes
- Add YCBCR 4:2:0 support
- Drop set_busid hook
- Refactor fb_helper locking
- Remove a bunch of internal APIs
- Add a bunch of better default handlers
- Format modifier/blob plane property added
- More internal header refactoring
- Make more internal API names consistent
- Enhanced syncobj APIs (wait/signal/reset/create signalled)
bridge:
- Add Synopsys Designware MIPI DSI host bridge driver
tiny:
- Add Pervasive Displays RePaper displays
- Add support for LEGO MINDSTORMS EV3 LCD
i915:
- Lots of GEN10/CNL support patches
- drm syncobj support
- Skylake+ watermark refactoring
- GVT vGPU 48-bit ppgtt support
- GVT performance improvements
- NOA change ioctl
- CCS (color compression) scanout support
- GPU reset improvements
amdgpu:
- Initial hugepage support
- BO migration logic rework
- Vega10 improvements
- Powerplay fixes
- Stop reprogramming the MC
- Fixes for ACP audio on stoney
- SR-IOV fixes/improvements
- Command submission overhead improvements
amdkfd:
- Non-dGPU upstreaming patches
- Scratch VA ioctl
- Image tiling modes
- Update PM4 headers for new firmware
- Drop all BUG_ONs.
nouveau:
- GP108 modesetting support.
- Disable MSI on big endian.
vmwgfx:
- Add fence fd support.
msm:
- Runtime PM improvements
exynos:
- NV12MT support
- Refactor KMS drivers
imx-drm:
- Lock scanout channel to improve memory bw
- Cleanups
etnaviv:
- GEM object population fixes
tegra:
- Prep work for Tegra186 support
- PRIME mmap support
sunxi:
- HDMI support improvements
- HDMI CEC support
omapdrm:
- HDMI hotplug IRQ support
- Big driver cleanup
- OMAP5 DSI support
rcar-du:
- vblank fixes
- VSP1 updates
arcgpu:
- Minor fixes
stm:
- Add STM32 DSI controller driver
dw_hdmi:
- Add support for Rockchip RK3399
- HDMI CEC support
atmel-hlcdc:
- Add 8-bit color support
vc4:
- Atomic fixes
- New ioctl to attach a label to a buffer object
- HDMI CEC support
- Allow userspace to dictate rendering order on submit ioctl"
* tag 'drm-for-v4.14' of git://people.freedesktop.org/~airlied/linux: (1074 commits)
drm/syncobj: Add a signal ioctl (v3)
drm/syncobj: Add a reset ioctl (v3)
drm/syncobj: Add a syncobj_array_find helper
drm/syncobj: Allow wait for submit and signal behavior (v5)
drm/syncobj: Add a CREATE_SIGNALED flag
drm/syncobj: Add a callback mechanism for replace_fence (v3)
drm/syncobj: add sync obj wait interface. (v8)
i915: Use drm_syncobj_fence_get
drm/syncobj: Add a race-free drm_syncobj_fence_get helper (v2)
drm/syncobj: Rename fence_get to find_fence
drm: kirin: Add mode_valid logic to avoid mode clocks we can't generate
drm/vmwgfx: Bump the version for fence FD support
drm/vmwgfx: Add export fence to file descriptor support
drm/vmwgfx: Add support for imported Fence File Descriptor
drm/vmwgfx: Prepare to support fence fd
drm/vmwgfx: Fix incorrect command header offset at restart
drm/vmwgfx: Support the NOP_ERROR command
drm/vmwgfx: Restart command buffers after errors
drm/vmwgfx: Move irq bottom half processing to threads
drm/vmwgfx: Don't use drm_irq_[un]install
...
The reason behind the original indirection through the helper
functions was to allow existing drivers to overwrite how they handle
properties. For example when a vendor-specific userspace had
expectations that didn't match atomic. That seemed likely, since
atomic is standardizing a _lot_ more of the behaviour of a kms driver.
But 20 drivers later there's no such need at all. Worse, this forces
all drivers to hook up the default behaviour, breaking userspace if
they forget to do that. And it forces us to export a bunch of core
function just for those helpers.
And finally, these helpers are the last places using
drm_atomic_legacy_backoff() and the implicit acquire_ctx.
This patch here just implements the new behaviour and updates the
docs. Follow-up patches will garbage-collect all the dead code.
v2: Fixup docs even better!
v3: Make it actually work ...
v4: Drop the uses_atomic_modeset() checks from the previous patch
again, since they're now moved up in the callchain.
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org> (v3)
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170725120204.2107-1-daniel.vetter@ffwll.ch
Problem : While running IGT kms_atomic_transition test suite i encountered
a hang in drmHandleEvent immediately following an atomic_commit.
After dumping the atomic state I relized that in this case there was
not even one CRTC attached to the state and only disabled
planes. This probably due to a commit which hadn't changed any property
which would require attaching crtc state. This means drmHandleEvent
will never wake up from read since without CRTC in atomic state
the event fd will not be signaled.
Fix: Protect against this issue by failing atomic_commit early in
drm_mode_atomic_commit where such probelm can be identified.
v2:
Fix typos and extra newlines.
Change-Id: I3ee28ffae35fd1e8bfe553146c44da53da02e6f8
Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1497981426-27203-1-git-send-email-Andrey.Grodzovsky@amd.com
Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ defines to the UAPI
as a convenience.
Ideally the DRM_ROTATE_ and DRM_REFLECT_ property ids are looked up
through the atomic API, but realizing that userspace is likely to take
shortcuts and assume that the enum values are what is sent over the
wire.
As a result these defines are provided purely as a convenience to
userspace applications.
Changes since v3:
- Switched away from past tense in comments
- Add define name change to previously mis-spelled DRM_REFLECT_X comment
- Improved the comment for the DRM_MODE_REFLECT_<axis> comment
Changes since v2:
- Changed define prefix from DRM_MODE_PROP_ to DRM_MODE_
- Fix compilation errors
- Changed comment formatting
- Deduplicated comment lines
- Clarified DRM_MODE_PROP_REFLECT_ comment
Changes since v1:
- Moved defines from drm.h to drm_mode.h
- Changed define prefix from DRM_ to DRM_MODE_PROP_
- Updated uses of the defines to the new prefix
- Removed include from drm_rect.c
- Stopped using the BIT() macro
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519205017.23307-2-robert.foss@collabora.com
Some connectors may not allow all scaling mode properties, this function will allow
creating the scaling mode property with only the supported subset. It also wires up
this state for atomic.
This will make it possible to convert i915 connectors to atomic.
Changes since v1:
- Add DRM_MODE_PROP_ENUM flag to drm_property_create
- Use the correct index in drm_property_add_enum.
- Add DocBook for function (Sean Paul).
- Warn if less than 2 valid scaling modes are passed.
- Remove level of indent. (Sean Paul)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170501133804.8116-3-maarten.lankhorst@linux.intel.com
[mlankhorst: Rename function, fix docbook issues]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
It is necessary to track states for objects other than connector, crtc
and plane for atomic modesets. But adding objects like DP MST link
bandwidth to drm_atomic_state would mean that a non-core object will be
modified by the core helper functions for swapping and clearing
it's state. So, lets add void * objects and helper functions that operate
on void * types to keep these objects and states private to the core.
Drivers can then implement specific functions to swap and clear states.
The other advantage having just void * for these objects in
drm_atomic_state is that objects of different types can be managed in the
same state array.
v7: Use __for_each_private_obj to define for_each_private_obj (Maarten)
v6: More kernel-doc to keep 0-day happy
v5: Remove more NULL checks (Maarten)
v4: Avoid redundant NULL checks when private_objs array is empty (Maarten)
v3: Macro alignment (Chris)
v2: Added docs and new iterator to filter private objects (Daniel)
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <Harry.wentland@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1492753893-3748-2-git-send-email-dhinakaran.pandiyan@intel.com
If we push the locks down we don't have to take them all at the same
time.
Aside: Making dump_info fully safe should be fairly simple, if we
protect the ->state pointers with rcu. Simply putting a
synchronize_rcu() into the drm_atomic_state free function should be
all that's roughly needed. Well except we shouldn't block in there, so
better to put that into a work_struct. But I've not set out to fix
that little issue.
Cc: Rob Clark <robdclark@gmail.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/20170403083304.9083-6-daniel.vetter@ffwll.ch
Currently the functions that initialize and tear down a connector
iterator use the _get() and _put() suffixes. However, these suffixes
are typically used by reference counting functions.
Make these function names a little more consistent by changing the
suffixes to _begin() and _end(), which is a fairly common pattern in
the rest of the Linux kernel.
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170228144643.5668-8-thierry.reding@gmail.com
For consistency with other reference counting APIs in the kernel, add
drm_property_blob_get() and drm_property_blob_put() to reference count
DRM blob properties.
Compatibility aliases are added to keep existing code working. To help
speed up the transition, all the instances of the old functions in the
DRM core are already replaced in this commit.
A semantic patch is provided that can be used to convert all drivers to
the new helpers.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170228144643.5668-7-thierry.reding@gmail.com
For consistency with other reference counting APIs in the kernel, add
drm_framebuffer_get() and drm_framebuffer_put() to reference count DRM
framebuffers.
Compatibility aliases are added to keep existing code working. To help
speed up the transition, all the instances of the old functions in the
DRM core are already replaced in this commit.
The existing semantic patch for the DRM subsystem-wide conversion is
extended to account for these new helpers.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170228144643.5668-5-thierry.reding@gmail.com
For consistency with other reference counting APIs in the kernel, add
drm_connector_get() and drm_connector_put() functions to reference count
connectors.
Compatibility aliases are added to keep existing code working. To help
speed up the transition, all the instances of the old functions in the
DRM core are already replaced in this commit.
The existing semantic patch for mode object reference count conversion
is extended for these new helpers.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170228144643.5668-4-thierry.reding@gmail.com
For consistency with other reference counting APIs in the kernel, add
drm_mode_object_get() and drm_mode_object_put() to reference count DRM
mode objects.
Compatibility aliases are added to keep existing code working. To help
speed up the transition, all the instances of the old functions in the
DRM core are already replaced in this commit.
A semantic patch is provided that can be used to convert all drivers to
the new helpers.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170228144643.5668-3-thierry.reding@gmail.com
Instead of trying to do everything in 1 go, just do a basic safe
conversion first. We've been bitten by too many regressions in the
past.
This patch only converts drm_framebuffer_remove to atomic. The
regression sensitive part is split out to a separate patch.
v2:
- Remove plane->fb assignment, done by drm_atomic_clean_old_fb.
- Add WARN_ON when atomic_remove_fb fails.
- Always call drm_atomic_state_put.
v3:
- Use drm_drv_uses_atomic_modeset
- Handle the case where the first plane-disable-only commit fails
with -EINVAL. Some drivers do not support this, fall back to
disabling all crtc's in this case.
v4:
- Solve vmwgfx compatibility issue in their driver, was fixed in this
patch by v3.
- Move only disabling primary to a separate patch.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1487685102-31991-3-git-send-email-maarten.lankhorst@linux.intel.com
At the time userspace does setcrtc, we've already promised the mode
would work. The promise is based on the theoretical capabilities of
the link, but it's possible we can't reach this in practice. The DP
spec describes how the link should be reduced, but we can't reduce
the link below the requirements of the mode. Black screen follows.
One idea would be to have setcrtc return a failure. However, it
already should not fail as the atomic checks have passed. It would
also conflict with the idea of making setcrtc asynchronous in the
future, returning before the actual mode setting and link training.
Another idea is to train the link "upfront" at hotplug time, before
pruning the mode list, so that we can do the pruning based on
practical not theoretical capabilities. However, the changes for link
training are pretty drastic, all for the sake of error handling and
DP compliance, when the most common happy day scenario is the current
approach of link training at mode setting time, using the optimal
parameters for the mode. It is also not certain all hardware could do
this without the pipe on; not even all our hardware can do this. Some
of this can be solved, but not trivially.
Both of the above ideas also fail to address link degradation *during*
operation.
The solution is to add a new "link-status" connector property in order
to address link training failure in a way that:
a) changes the current happy day scenario as little as possible, to
avoid regressions, b) can be implemented the same way by all drm
drivers, c) is still opt-in for the drivers and userspace, and opting
out doesn't regress the user experience, d) doesn't prevent drivers
from implementing better or alternate approaches, possibly without
userspace involvement. And, of course, handles all the issues presented.
In the usual happy day scenario, this is always "good". If something
fails during or after a mode set, the kernel driver can set the link
status to "bad" and issue a hotplug uevent for userspace to have it
re-check the valid modes through GET_CONNECTOR IOCTL, and try modeset
again. If the theoretical capabilities of the link can't be reached,
the mode list is trimmed based on that.
v7 by Jani:
* Rebase, simplify set property while at it, checkpatch fix
v6:
* Fix a typo in kernel doc (Sean Paul)
v5:
* Clarify doc for silent rejection of atomic properties by driver (Daniel Vetter)
v4:
* Add comments in kernel-doc format (Daniel Vetter)
* Update the kernel-doc for link-status (Sean Paul)
v3:
* Fixed a build error (Jani Saarinen)
v2:
* Removed connector->link_status (Daniel Vetter)
* Set connector->state->link_status in drm_mode_connector_set_link_status_property
(Daniel Vetter)
* Set the connector_changed flag to true if connector->state->link_status changed.
* Reset link_status to GOOD in update_output_state (Daniel Vetter)
* Never allow userspace to set link status from Good To Bad (Daniel Vetter)
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Tony Cheng <tony.cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Eric Anholt <eric@anholt.net> (for the -modesetting patch)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/0182487051aa9f1594820e35a4853de2f8747b4e.1481883920.git.jani.nikula@intel.com
Backmerge the main pull request to sync up with all the newly landed
drivers. Otherwise we'll have chaos even before 4.12 started in
earnest.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
This was somehow lost between v3 and the merged version in Maarten's
patch merged as:
commit f2d580b9a8
Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date: Wed May 4 14:38:26 2016 +0200
drm/core: Do not preserve framebuffer on rmfb, v4.
This introduces a slight behavioral change to rmfb. Instead of
disabling a crtc when the primary plane is disabled, we try to
preserve it.
Apart from old versions of the vmwgfx xorg driver, there is
nothing depending on rmfb disabling a crtc. Since vmwgfx is
a legacy driver we can safely only disable the plane with atomic.
If this commit is rejected by the driver then we will still fall
back to the old behavior and turn off the crtc.
v2:
- Remove plane->fb assignment, done by drm_atomic_clean_old_fb.
- Add WARN_ON when atomic_remove_fb fails.
- Always call drm_atomic_state_put.
v3:
- Use drm_drv_uses_atomic_modeset
- Handle the case where the first plane-disable-only commit fails
with -EINVAL. Some drivers do not support this, fall back to
disabling all crtc's in this case.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/66fc3da5-697b-1613-0a67-a5293209f0dc@linux.intel.com
Most DRM messages include three pieces of information: the type of the
component (CRTC, ENCODER, CONNECTOR etc), the DRM object ID of the
component, and the component name. However, there are some messages
which omit the last piece of identifying information. This makes it
harder to debug failures when these messages are printed, because the
DRM object ID doesn't supply enough information to know which piece of
hardware had a problem.
Update the atomic modeset code to always print the component name along
with the type and DRM object ID.
Fixes: 4cba68507c ("drm/atomic-helper: Reject legacy flips on a disabled pipe")
Fixes: 8d4d0d700d ("drm/atomic-helper: Print an error if vblank wait times out")
Fixes: 5481c8fb1d ("drm/atomic-helper: Check encoder/crtc constraints")
Fixes: 99cf4a29fa ("drm/atomic: Add current-mode blob to CRTC state")
Fixes: cc4ceb484b ("drm: Global atomic state handling")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
[danvet: Wiggle in conflicting hunk.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Add for_each_(old)(new)_(plane,connector,crtc)_in_state iterators to
replace the old for_each_xxx_in_state ones. This is useful for >1 flip
depth and getting rid of all xxx->state dereferences.
This requires extra fixups done when committing a state after
duplicating, which in general isn't valid but is used by suspend/resume.
To handle these, introduce drm_atomic_helper_commit_duplicated_state
which performs those fixups before checking & committing the state.
Changes since v1:
- Remove nonblock parameter for commit_duplicated_state.
Changes since v2:
- Use commit_duplicated_state for i915 load detection.
- Add WARN_ON(old_state != obj->state) before swapping.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1484559464-27107-2-git-send-email-maarten.lankhorst@linux.intel.com
The requirements for connector_list locking are a bit tricky:
- We need to be able to jump over zombie conectors (i.e. with refcount
== 0, but not yet removed from the list). If instead we require that
there's no zombies on the list then the final kref_put must happen
under the list protection lock, which means that locking context
leaks all over the place. Not pretty - better to deal with zombies
and wrap the locking just around the list_del in the destructor.
- When we walk the list we must _not_ hold the connector list lock. We
walk the connector list at an absolutely massive amounts of places,
if all those places can't ever call drm_connector_unreference the
code would get unecessarily complicated.
- connector_list needs it own lock, again too many places that walk it
that we could reuse e.g. mode_config.mutex without resulting in
inversions.
- Lots of code uses these loops to look-up a connector, i.e. they want
to be able to call drm_connector_reference. But on the other hand we
want connectors to stay on that list until they're dead (i.e.
connector_list can't hold a full reference), which means despite the
"can't hold lock for the loop body" rule we need to make sure a
connector doesn't suddenly become a zombie.
At first Dave&I discussed various horror-show approaches using srcu,
but turns out it's fairly easy:
- For the loop body we always hold an additional reference to the
current connector. That means it can't zombify, and it also means
it'll stay on the list, which means we can use it as our iterator to
find the next connector.
- When we try to find the next connector we only have to jump over
zombies. To make sure we don't chase bad pointers that entire loop
is protected with the new connect_list_lock spinlock. And because we
know that we're starting out with a non-zombie (need to drop our
reference for the old connector only after we have our new one),
we're guranteed to still be on the connector_list and either find
the next non-zombie or complete the iteration.
- Only downside is that we need to make sure that the temporary
reference for the loop body doesn't leak. iter_get/put() functions +
lockdep make sure that's the case.
- To avoid a flag day the new iterator macro has an _iter postfix. We
can rename it back once all the users of the unsafe version are gone
(there's about 100 list walkers for the connector_list).
For now this patch only converts all the list walking in the core,
leaving helpers and drivers for later patches. The nice thing is that
we can now finally remove 2 FIXME comments from the
register/unregister functions.
v2:
- use irqsafe spinlocks, so that we can use this in drm_state_dump
too.
- nuke drm_modeset_lock_all from drm_connector_init, now entirely
cargo-culted nonsense.
v3:
- do {} while (!kref_get_unless_zero), makes for a tidier loop (Dave).
- pretty kerneldoc
- add EXPORT_SYMBOL, helpers&drivers are supposed to use this.
v4: Change lockdep annotations to only check whether we release the
iter fake lock again (i.e. make sure that iter_put is called), but
not check any locking dependecies itself. That seams to require a
recursive read lock in trylock mode.
Cc: Dave Airlie <airlied@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213230814.19598-6-daniel.vetter@ffwll.ch
