While ttm_dma_pool_shrink_scan() tries to take mutex before doing GFP_KERNEL
allocation, ttm_pool_shrink_scan() does not do it. This can result in stack
overflow if kmalloc() in ttm_page_pool_free() triggered recursion due to
memory pressure.
shrink_slab()
=> ttm_pool_shrink_scan()
=> ttm_page_pool_free()
=> kmalloc(GFP_KERNEL)
=> shrink_slab()
=> ttm_pool_shrink_scan()
=> ttm_page_pool_free()
=> kmalloc(GFP_KERNEL)
Change ttm_pool_shrink_scan() to do like ttm_dma_pool_shrink_scan() does.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@kernel.org> [2.6.35+]
Signed-off-by: Dave Airlie <airlied@redhat.com>
I can observe that RHEL7 environment stalls with 100% CPU usage when a
certain type of memory pressure is given. While the shrinker functions
are called by shrink_slab() before the OOM killer is triggered, the stall
lasts for many minutes.
One of reasons of this stall is that
ttm_dma_pool_shrink_count()/ttm_dma_pool_shrink_scan() are called and
are blocked at mutex_lock(&_manager->lock). GFP_KERNEL allocation with
_manager->lock held causes someone (including kswapd) to deadlock when
these functions are called due to memory pressure. This patch changes
"mutex_lock();" to "if (!mutex_trylock()) return ...;" in order to
avoid deadlock.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@kernel.org> [3.3+]
Signed-off-by: Dave Airlie <airlied@redhat.com>
We can use "unsigned int" instead of "atomic_t" by updating start_pool
variable under _manager->lock. This patch will make it possible to avoid
skipping when choosing a pool to shrink in round-robin style, after next
patch changes mutex_lock(_manager->lock) to !mutex_trylock(_manager->lork).
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@kernel.org> [3.3+]
Signed-off-by: Dave Airlie <airlied@redhat.com>
list_empty(&_manager->pools) being false before taking _manager->lock
does not guarantee that _manager->npools != 0 after taking _manager->lock
because _manager->npools is updated under _manager->lock.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@kernel.org> [3.3+]
Signed-off-by: Dave Airlie <airlied@redhat.com>
This series of patches add the support of DRM/KMS drivers for STMicroelectronics
chipsets stih416 and stih407.
Hardware is split in two main blocks: Compositor and TVout. Each of them
includes specific hardware IPs and the display timing are controlled by a specific
Video Timing Generator hardware IP (VTG).
Compositor is made of the follow hardware IPs:
- GDP (Generic Display Pipeline) which is an entry point for graphic (RGB)
buffers
- VDP (Video Diplay Pipeline) which is an entry point for video (YUV) buffers
- HQVDP (High Quality Video Display Processor) that supports scaling,
deinterlacing and some miscellaneous image quality improvements.
It fetches the Video decoded buffers from memory, processes them and pushes
them to the Compositor through a HW dedicated bus.
- Mixer is responsible of mixing all the entries depending of their
respective z-order and layout
TVout is divided in 3 parts:
- HDMI to generate HDMI signals, depending of chipset version HDMI phy can
change.
- HDA to generate signals for HD analog TV
- VIP to control/switch data path coming from Compositor
On stih416 compositor and Tvout are on different dies so a Video Trafic Advance
inter-die Communication mechanism (VTAC) is needed.
+---------------------------------------------+ +----------------------------------------+
| +-------------------------------+ +----+ | | +----+ +--------------------------+ |
| | | | | | | | | | +---------+ +----+ | |
| | +----+ +------+ | | | | | | | | | VIP |---->|HDMI| | |
| | |GPD +------------->| | | | | | | | | | | | +----+ | |
| | +----+ |Mixer |--|-->| | | | | |---|->| switcher| | |
| | | | | | | | | | | | | | +----+ | |
| | | | | | | | | | | | | |---->|HDA | | |
| | +------+ | |VTAC|========>|VTAC| | +---------+ +----+ | |
| | | | | | | | | | | |
| | Compositor | | | | | | | | TVout | |
| +-------------------------------+ | | | | | | +--------------------------+ |
| ^ | | | | | | ^ |
| | | | | | | | | |
| +--------------+ | | | | | | +-------------+ |
| | VTG (master) |----->| | | | | |----->| VTG (slave) | |
| +--------------+ +----+ | | +----+ +-------------+ |
|Digital die | | Analog Die|
+---------------------------------------------+ +----------------------------------------+
On stih407 Compositor and Tvout are on the same die
+-----------------------------------------------------------------+
| +-------------------------------+ +--------------------------+ |
| | | | +---------+ +----+ | |
| | +----+ +------+ | | | VIP |---->|HDMI| | |
| | |GPD +------------->| | | | | | +----+ | |
| | +----+ |Mixer |--|--|->| switcher| | |
| | +----+ +-----+ | | | | | | +----+ | |
| | |VDP +-->+HQVDP+--->| | | | | |---->|HDA | | |
| | +----+ +-----+ +------+ | | +---------+ +----+ | |
| | | | | |
| | Compositor | | TVout | |
| +-------------------------------+ +--------------------------+ |
| ^ ^ |
| | | |
| +--------------+ |
| | VTG | |
| +--------------+ |
|Digital die |
+-----------------------------------------------------------------+
In addition of the drivers for the IPs listed before a thin I2C driver (hdmiddc) is used
by HDMI driver to retrieve EDID for monitor.
To unify interfaces of GDP and VDP we create a "layer" interface called by
compositor to control both GPD and VDP.
Hardware have memory contraints (alignment, contiguous) so we use CMA drm helpers functions
to allocate frame buffer.
File naming convention is:
- sti_* for IPs drivers
- sti_drm_* for drm functions implementation.
* 'drm_kms_for_next-v8' of git://git.linaro.org/people/benjamin.gaignard/kernel:
drm: sti: Add DRM driver itself
drm: sti: add Compositor
drm: sti: add Mixer
drm: sti: add VID layer
drm: sti: add GDP layer
drm: sti: add TVOut driver
drm: sti: add HDA driver
drm: sti: add HDMI driver
drm: sti: add VTAC drivers
drm: sti: add VTG driver
drm: sti: add bindings for DRM driver
This builds upon the previous set of fixes which were pulled on 6th July.
Included in this set are:
- an update from Jean-Francois to add the missing reg documentation entry
to the device tree documentation.
- conversion of the tda998x driver to the component helpers.
* 'tda998x-devel' of git://ftp.arm.linux.org.uk/~rmk/linux-cubox:
drm/i2c: tda998x: add component support
drm/i2c: tda998x: allow re-use of tda998x support code
drm/i2c: tda998x: fix lack of required reg in DT documentation
Conflicts:
drivers/gpu/drm/i2c/tda998x_drv.c
This time around we have a mix of new hw enablement (mdp5 v1.3 /
apq8084), plus devicetree and various upstream changes (mostly
adapting to CCF vs downstream clk driver differences) for mdp4 /
apq8064. With these drm/msm patches plus a few other small patchsets
(from linaro qcom integration branch.. mostly stuff queued up for
3.17) we have the inforce ifc6410 board working, with gpu. Much nicer
to work with than ancient vendor android branch :-)
* 'msm-next' of git://people.freedesktop.org/~robclark/linux:
drm/msm/hdmi: fix HDMI_MUX_EN gpio request typo
drm/msm/hdmi: enable lpm-mux if it is present
drm/msm/mdp5: add support for MDP5 v1.3
drm/msm: fix potential deadlock in gpu init
drm/msm: use upstream iommu
drm/msm: no mmu is only error if not using vram carveout
drm/msm: fix BUG_ON() in error cleanup path
drm/msm/mdp4: add mdp axi clk
drm/msm: hdmi phy 8960 phy pll
drm/msm: update generated headers
drm/msm: DT support for 8960/8064 (v3)
drm/msm: Implement msm drm fb_mmap callback function
drm/msm: activate iommu support
drm/msm: fix double struct_mutex acquire
HDMI_MUX_EN gpio is requested. If an error occurs, the same name
should be printed (HDMI_MUX_EN) instead of HDMI_MUX_SEL (typo).
Signed-off-by: Beeresh Gopal <gbeeresh@codeaurora.org>
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Rob Clark <robdclark@gmail.com>
lpm-mux is programmed to enable HDMI connector
on the docking station for S805 chipset based
devices.
Signed-off-by: Beeresh Gopal <gbeeresh@codeaurora.org>
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
MDP5 has several functional blocks (ie: VIG/RGB pipes, LMs, ...).
From one revision to another, these blocks' base addresses might
change due to the number of instances present in the MDP5 hw.
A way of dealing with these offset changes is to introduce
dynamic offsets 'per block'.
This change adds support for the new revision of MDP5: v1.3.
The idea is to define one hw config per MDP version and select
either one of them at runtime, after reading the MDP5 version.
Once the MDP version is known, 'per block' dynamic offsets
are initialized through a global pointer, which is then used for
read/write register access.
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Somewhere along the way, the firmware loader sprouted another lock
dependency, resulting in possible deadlock scenario:
&dev->struct_mutex --> &sb->s_type->i_mutex_key#2 --> &mm->mmap_sem
which is problematic vs things like gem mmap.
So introduce a separate mutex to synchronize gpu init.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Downstream kernel IOMMU had a non-standard way of dealing with multiple
devices and multiple ports/contexts. We don't need that on upstream
kernel, so rip out the crazy.
Note that we have to move the pinning of the ringbuffer to after the
IOMMU is attached. No idea how that managed to work properly on the
downstream kernel.
For now, I am leaving the IOMMU port name stuff in place, to simplify
things for folks trying to backport latest drm/msm to device kernels.
Once we no longer have to care about pre-DT kernels, we can drop this
and instead backport upstream IOMMU driver.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Downstream kernel holds this clk via a fake-parent relationship.
Upstream clock framework requires that we hold it explicitly.
Signed-off-by: Rob Clark <robdclark@gmail.com>
On downstream kernel the clk driver directly bangs hdmi phy registers.
For upstream kernel, we need to model this as a clock and register with
the clock framework.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Now that we (almost) have enough dependencies in place (MMCC, RPM, etc),
add necessary DT support so that we can use drm/msm on upstream kernel.
v2: update for review comments
v3: rebase on component helper changes
Signed-off-by: Rob Clark <robdclark@gmail.com>
This change implements msm drm specific fb_mmap function for fb device
to properly map the fb address to userspace.
Signed-off-by: Hai Li <hali@codeaurora.org>
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com> (+ minor comment tweak)
This changes activates the iommu support for MDP5, through the
platform config structure.
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
When tegra-drm.ko is built as a module, these MODULE_DEVICE_TABLEs allow
the module to be auto-loaded since the module will match the devices
instantiated from device tree.
(Notes for stable: in 3.14+, just git rm any conflicting file, since they
are added in later kernels. For 3.13 and below, manual merging will be
needed)
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Since the device will no longer be used, may as well keep it in reset to
potentially save some power and make sure it is in a clean state the
next time it's probed.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Tegra20 and Tegra30 both required the buffer line stride to be aligned
on 8 byte boundaries. Tegra114 and Tegra124 increased the alignment to
64 bytes. Introduce a parameter to specify the alignment requirements
for each display controller and round up the pitch of newly allocated
framebuffers appropriately.
Originally-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
This change uses the value of bits-per-color from panel to remove one
more hardcoded value.
Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Job submission currently relies on the fact that struct drm_tegra_reloc
and struct host1x_reloc are the same size and uses a simple call to the
copy_from_user() function to copy them to kernel space. This causes the
handle to be stored in the buffer object field, which then needs a cast
to a 32 bit integer to resolve it to a proper buffer object pointer and
store it back in the buffer object field.
On 64-bit architectures that will no longer work, since pointers are 64
bits wide whereas handles will remain 32 bits. This causes the sizes of
both structures to because different and copying will no longer work.
Fix this by adding a new function, host1x_reloc_get_user(), that copies
the structures field by field.
While at it, use substructures for the command and target buffers in
struct host1x_reloc for better readability. Also use unsized types to
make it more obvious that this isn't part of userspace ABI.
Signed-off-by: Thierry Reding <treding@nvidia.com>
This matches what other drivers do for equivalent IOCTLs.
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The DRM_TEGRA_GEM_SET_FLAGS IOCTL can be used to set the flags of a
buffer object after it has been allocated or imported. Flags associated
with a buffer object can be queried using the DRM_TEGRA_GEM_GET_FLAGS
IOCTL.
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Currently the tiling parameters of buffer objects can only be set at
allocation time, and only a single tiled mode is supported. This new
DRM_TEGRA_GEM_SET_TILING IOCTL allows more modes to be set and also
allows the tiling mode to be changed after the allocation. This will
enable the Tegra DRM driver to import buffers from a GPU and directly
scan them out by configuring the display controller appropriately.
To complement this, the DRM_TEGRA_GEM_GET_TILING IOCTL can query the
current tiling mode of a buffer object. This is necessary when importing
buffers via handle (as is done in Mesa for example) so that userspace
can determine the proper parameters for the 2D or 3D engines.
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Tegra124 supports a block-linear mode in addition to the regular pitch
linear and tiled modes. Add support for these by moving the internal
representation into a structure rather than a simple flag.
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Handle the MIPI_DSI_CLOCK_NONCONTINUOUS flag and only set TX-only
clock behavior when this flag is present to allow panels requiring
continuous clock mode to operate with this driver.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
We should unlock before returning the error code.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Final feature pull for 3.17.
drm-intel-next-2014-07-25:
- Ditch UMS support (well just the config option for now)
- Prep work for future platforms (Sonika Jindal, Damien)
- runtime pm/soix fixes (Paulo, Jesse)
- psr tracking improvements, locking fixes, now enabled by default!
- rps fixes for chv (Deepak, Ville)
- drm core patches for rotation support (Ville, Sagar Kamble) - the i915 parts
unfortunately didn't make it yet
- userptr fixes (Chris)
- minimum backlight brightness (Jani), acked long ago by Matthew Garret on irc -
I've forgotten about this patch :(
QA is a bit unhappy about the DP MST stuff since it broke hpd testing a
bit, but otherwise looks sane. I've backmerged drm-next to resolve
conflicts with the mst stuff, which means the new tag itself doesn't
contain the overview as usual.
* tag 'drm-intel-next-2014-07-25-merged' of git://anongit.freedesktop.org/drm-intel: (75 commits)
drm/i915/userptr: Keep spin_lock/unlock in the same block
drm/i915: Allow overlapping userptr objects
drm/i915: Ditch UMS config option
drm/i915: respect the VBT minimum backlight brightness
drm/i915: extract backlight minimum brightness from VBT
drm/i915: Replace HAS_PCH_SPLIT which incorrectly lets some platforms in
drm/i915: Returning from increase/decrease of pllclock when invalid
drm/i915: Setting legacy palette correctly for different platforms
drm/i915: Avoid incorrect returning for some platforms
drm/i915: Writing proper check for reading of pipe status reg
drm/i915: Returning the right VGA control reg for platforms
drm/i915: Allowing changing of wm latencies for valid platforms
drm/i915: Adding HAS_GMCH_DISPLAY macro
drm/i915: Fix possible overflow when recording semaphore states.
drm/i915: Do not unmap object unless no other VMAs reference it
drm/i915: remove plane/cursor/pipe assertions from intel_crtc_disable
drm/i915: Reorder ctx unref on ppgtt cleanup
drm/i915/error: Check the potential ctx obj's vm
drm/i915: Fix printing proper min/min/rpe values in debugfs
drm/i915: BDW can also detect unclaimed registers
...
Daniel pointed out with hotplug that userspace could be trying to oops us
as root for lols, and that to be correct we shouldn't register the object
with the idr before we have fully set the connector object up.
His proposed solution was a lot more life changing, this seemed like a simpler
proposition to me, get the connector object id from the idr, but don't
register the object until the drm_connector_register callback.
The open question is whether the drm_mode_object_register needs a bigger lock
than just the idr one, but I can't see why it would, but I can be locking
challenged.
v2: fix bool noreg into sane - add comment.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
On HSW+, the digital encoders are shared between HDMI and DP outputs,
with one encoder masquerading as both. The VBT should tell us if we need
to have DP or HDMI support on a particular port, but if we don't have DP
support and we enable the DP hpd pulse handler then we cause an oops.
Don't hook up the DP hpd handling if we don't have a DP port.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81856
Reported-by: Intel QA Team.
Signed-off-by: Dave Airlie <airlied@redhat.com> # v1
[ickle: Fix the error handling after a malloc failure]
Reviewed-by: Dave Airlie <airlied@redhat.com>
Cc: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This pull request includes i80 interface support, module auto-loading
ipp consolidation, and trivail fixups and cleanups.
Summary:
- Add i80 interface support. For this, we added some features to
Exynos drm framework, which don't affect any other SoC and common
framework because they are specific to Exynos drm.
- Add module auto-loading support. For this, sub drivers of Exynos drm
exports their of match tables to userspace. This allows modules to be
loaded automatically based on devicetree information
- Consolidate ipp driver. This patch just just includes cleanups and
a littl bit refactoring codes.
If there is any problem, please kindly let me know.
* 'exynos-drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos: (38 commits)
drm/exynos: g2d: let exynos_g2d_get_ver_ioctl fail
drm/exynos: g2d: make ioctls more robust
drm/exynos: hdmi: add null check for hdmiphy_port
drm/exynos: control blending of mixer graphic layer 0
drm/exynos: Add MODULE_DEVICE_TABLE entries for various components
Subject: Revert "drm/exynos: remove MODULE_DEVICE_TABLE definitions"
Subject: Revert "drm/exynos: fix module build error"
drm/exynos/ipp: simplify ipp_find_driver
drm/exynos/ipp: simplify ipp_create_id
drm/exynos/ipp: remove redundant messages
drm/exynos/ipp: simplify ipp_find_obj
drm/exynos/ipp: remove useless registration checks
drm/exynos/ipp: simplify memory check function
drm/exynos/ipp: remove incorrect checks of list_first_entry result
drm/exynos/ipp: remove temporary variable
drm/exynos/ipp: correct address type
drm/exynos/ipp: remove struct exynos_drm_ipp_private
drm/exynos/ipp: remove unused field from exynos_drm_ipp_private
drm/exynos/ipp: remove type casting
drm/exynos: g2d: add exynos4212 as a compatible device.
...
Currently the DRM_IOCTL_EXYNOS_G2D_GET_VER ioctl always succeeds, even
if no G2D support is available. Let the ioctl fail when this is the
case, so that userspace can accurately probe for G2D support.
This also fixes the exynos tests in libdrm. There 'g2d_init' doesn't
fail when G2D is absent, leading to a segfault later.
Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: INki Dae <inki.dae@samsung.com>
Both exynos_g2d_set_cmdlist_ioctl and exynos_g2d_exec_ioctl don't check
if the G2D was succesfully probe. If that is not the case, then g2d_priv
is just NULL and extracting 'dev' from it in the next step is going to
produce a kernel oops.
Add proper checks and return ENODEV if the G2D is not available.
Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: INki Dae <inki.dae@samsung.com>
The hdmiphy can be apb and hdmiphy_port can be null. So before
accessing hdmiphy_port, it should be checked.
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
The mixer graphic layer 0 isn't blended as default by commit
0377f4ed9f1aed30292c4e3c87f24e028ae26f36(drm/exynos: Don't blend mixer
layer 0). But it needs to be blended with graphic layer 0 if video layer
is enabled by vp because video layer is bottom.
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Add MODULE_DEVICE_TABLE calls for the various OF match tables that
currently don't have one. This allows the module to be
autoloaded based on devicetree information.
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
This reverts commit d089621896 was
original to prevent multiple MODULE_DEVICE_TABLE in one module.
Which, as a side-effect broke autoloading of the module.
Since 21bdd17b21 it is possible to have
multiple calls to MODULE_DEVICE_TABLE, so the patch can be
reverted to restore support for autoloading
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Since 21bdd17b21 it is possible to have
multiple calls to MODULE_DEVICE_TABLE, so the patch can be
reverted to restore support for autoloading
Conflicts:
drivers/gpu/drm/exynos/exynos_drm_fimd.c
drivers/gpu/drm/exynos/exynos_drm_g2d.c
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Pull timer fixes from Thomas Gleixner:
"Two fixes in the timer area:
- a long-standing lock inversion due to a printk
- suspend-related hrtimer corruption in sched_clock"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timer: Fix lock inversion between hrtimer_bases.lock and scheduler locks
sched_clock: Avoid corrupting hrtimer tree during suspend
Tetsuo Handa