This commit updates TREE_RCU-kconfig.txt to reflect changes in RCU's
Kconfig setup.  This commit also updates rcutorture's Kconfig fragments
to account for Kconfig parameters that are now driven directly off of
other Kconfig parameters.

The #CHECK# prefix tells the rcutorture scripts to take no action to try
to set the Kconfig parameter, but to check that it does in fact get set.
This is useful for verifying that Kconfig parameters that are supposed
to be automatically set do in fact get set to the required values.
Reported-by: NPranith Kumar <bobby.prani@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit causes the rcutorture scripts to force RCU_EXPERT so that
these scripts can cause rcutorture to torture RCU in the various required
configurations.  However, SRCU-P, TASKS03, and TREE09 retain !RCU_EXPERT
in order to ensure testing of the vanilla configuration.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit updates rcutortures configuration-fragment files to account
for the move from the CONFIG_RCU_FANOUT_EXACT Kconfig parameter to the
new rcutree.rcu_fanout_exact= boot parameter.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The TASKS01, TASKS02, and TASKS03 rcutorture config fragments currently
set CONFIG_TASKS_RCU.  However, now that the value of this Kconfig
parameter is set via "select" statements, it is no longer necessary to
set it explicitly.  This commit therefore removes it from the Kconfig
fragments.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The current rcutorture testing does not do any cleanup operations.
This works because the srcu_struct is statically allocated, but it
does represent a memory leak of the associated dynamically allocated
->per_cpu_ref per-CPU variables.  However, rcutorture currently uses
a statically allocated srcu_struct, which cannot legally be passed to
cleanup_srcu_struct().  Therefore, this commit adds a second form
of srcu (called srcud) that dynamically allocates and frees the
associated per-CPU variables.  This commit also adds a ->cleanup()
member to rcu_torture_ops that is invoked at the end of the test,
after ->cb_barriers().  This ->cleanup() pointer is NULL for all
existing tests, and thus only used for scrud.  Finally, the SRCU-P
torture-test configuration selects scrud instead of srcu, with SRCU-N
continuing to use srcu, thereby testing both static and dynamic
srcu_struct structures.
Reported-by: N"Ahmed, Iftekhar" <ahmedi@onid.oregonstate.edu>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The rcutorture.c file uses several explicit memory barriers that can
easily be converted to smp_store_release() and smp_load_acquire(), which
improves maintainability and also improves performance a bit.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The locktorture long delays are in milliseconds rather than microseconds,
so this commit changes the name of the corresponding variable from
longdelay_us to longdelay_ms.
Reported-by: NBen Goodwyn <bgoodwyn@softnas.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

By default, with rcutorture.nreaders equal to -1, rcutorture provisions
N-1 reader kthreads, where N is the number of CPUs.  This avoids
rcutorture-induced stalls, but also avoids heavier levels of torture.
This commit therefore allows negative values of rcutorture.nreaders
to specify larger numbers of reader kthreads, so that for example
rcutorture.nreaders=-2 provisions N kthreads and rcutorture.nreaders=-5
provisions N+3 kthreads.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Update documentation, as suggested by Josh Triplett. ]

TREE03 has been especially effective at finding bugs lately.  This commit
makes it even more effective by speeding up its CPU hotplug testing and
increasing its NR_CPUs from 8 to 16.  TREE08's NR_CPUS is decreased from
16 to 8 in order to maintain the same test duration.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Given that the combination of PREEMPT_RCU and HOTPLUG_CPU is producing the
most bugs lately, this commit swaps the TREE03 and TREE04 rcu_node-tree
geometries so that the test exercising PREEMPT_RCU and HOTPLUG_CPU has
three-level rather than two-level rcu_node trees.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

torture_rwlock_read_unlock_irq() must use read_unlock_irqrestore()
instead of write_unlock_irqrestore().

Use read_unlock_irqrestore() instead of write_unlock_irqrestore().
Signed-off-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit moves from the old ACCESS_ONCE() API to the new READ_ONCE()
and WRITE_ONCE() APIs.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck:  Updated to include kernel/torture.c as suggested by Jason Low. ]

Pull drm fixes from Dave Airlie:
 "I really need to get back to sending these on my Friday, instead of my
  Monday morning, but nothing too amazing in here: a few amdkfd fixes, a
  few radeon fixes, i915 fixes, one tegra fix and one core fix"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm: Zero out invalid vblank timestamp in drm_update_vblank_count.
  drm/tegra: Don't use vblank_disable_immediate on incapable driver.
  drm/radeon: stop trying to suspend UVD sessions
  drm/radeon: more strictly validate the UVD codec
  drm/radeon: make UVD handle checking more strict
  drm/radeon: make VCE handle check more strict
  drm/radeon: fix userptr lockup
  drm/radeon: fix userptr BO unpin bug v3
  drm/amdkfd: Initialize sdma vm when creating sdma queue
  drm/amdkfd: Don't report local memory size
  drm/amdkfd: allow unregister process with queues
  drm/i915: Drop PIPE-A quirk for 945GSE HP Mini
  drm/i915: Sink rate read should be saved in deca-kHz
  drm/i915/dp: there is no audio on port A
  drm/i915: Add missing MacBook Pro models with dual channel LVDS
  drm/i915: Assume dual channel LVDS if pixel clock necessitates it
  drm/radeon: don't setup audio on asics that don't support it
  drm/radeon: disable semaphores for UVD V1 (v2)

misc i915 fixes.

* tag 'drm-intel-fixes-2015-05-08' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Drop PIPE-A quirk for 945GSE HP Mini
  drm/i915: Sink rate read should be saved in deca-kHz
  drm/i915/dp: there is no audio on port A
  drm/i915: Add missing MacBook Pro models with dual channel LVDS
  drm/i915: Assume dual channel LVDS if pixel clock necessitates it

Since commit 844b03f2 we make
sure that after vblank irq off, we return the last valid
(vblank count, vblank timestamp) pair to clients, e.g., during
modesets, which is good.

An overlooked side effect of that commit for kms drivers without
support for precise vblank timestamping is that at vblank irq
enable, when we update the vblank counter from the hw counter, we
can't update the corresponding vblank timestamp, so now we have a
totally mismatched timestamp for the new count to confuse clients.

Restore old client visible behaviour from before Linux 3.17, but
zero out the timestamp at vblank counter update (instead of disable
as in original implementation) if we can't generate a meaningful
timestamp immediately for the new vblank counter. This will fix
this regression, so callers know they need to retry again later
if they need a valid timestamp, but at the same time preserves
the improvements made in the commit mentioned above.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Cc: <stable@vger.kernel.org> #v3.17+

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Pull ARM fixes from Russell King:
 "A set of ARM fixes:

   - fix an off-by-one error in the iommu DMA ops, which caused errors
     with a 4GiB size.

   - remove comments mentioning the non-existent CONFIG_CPU_ARM1020_CPU_IDLE
     macro.

   - remove useless CONFIG_CPU_ICACHE_STREAMING_DISABLE blocks, where
     this symbol never appeared in any Kconfig.

   - fix Feroceon code to cope with a previous change correctly (it
     incorrectly left an additional word in an assembly structure
     definition)

   - avoid a misleading IRQ affinity warning in the ARM PMU code for
     IRQs which are already affine to their CPUs.

   - fix the node name printed in the IRQ affinity warning"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8352/1: perf: Fix the pmu node name in warning message
  ARM: 8351/1: perf: don't warn about missing interrupt-affinity property for PPIs
  ARM: 8350/1: proc-feroceon: Fix feroceon_proc_info macro
  ARM: 8349/1: arch/arm/mm/proc-arm925.S: remove dead #ifdef block
  ARM: 8348/1: remove comments on CPU_ARM1020_CPU_IDLE
  ARM: 8347/1: dma-mapping: fix off-by-one check in arm_setup_iommu_dma_ops

Pull samsung fixes from Kukjin Kim:
 "Here is Samsung fixes for v4.1.  Since I've missed to send this via
  arm-soc tree before v4.1-rc3, so I'm sending this to you directly

   - fix commit ea08de16 ("ARM: dts: Add DISP1 power domain for
     exynos5420") which causes 'unhandled fault: imprecise external
     abort' error when PD turned off.  ("make DP a consumer of DISP1
     power domain")

   - fix 's3c-rtc' probe failure on Odriod-X2/U2/U3 boards ("add
     'rtc_src' clock to rtc node for source clock of rtc")

   - fix typo for 'cpu-crit-0' trip point on exynos5420/5440

   - fix S2R failure on exynos5250-snow due to card power of Marvell
     WiFi driver (suspend/resume) ("add keep-power-in-susped to WiFi
     SDIO node")"

* tag 'samsung-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: dts: Add keep-power-in-suspend to WiFi SDIO node for exynos5250-snow
  ARM: dts: Fix typo in trip point temperature for exynos5420/5440
  ARM: dts: add 'rtc_src' clock to rtc node for exynos4412-odroid boards
  ARM: dts: Make DP a consumer of DISP1 power domain on Exynos5420

Pull ARM SoC fixes from Arnd Bergmann:
 "A few patches have come up since the merge window.  The largest one is
  a rewrite of the PXA lubbock/mainstone IRQ handling.  This was already
  broken in 2011 by a change to the GPIO code and only noticed now.

  The other changes contained here are:

  MAINTAINERS file updates:

   - Ray Jui and Scott Branden are now co-maintainers for some of the
     mach-bcm chips, while Christian Daudt and Marc Carino have stepped
     down.

   - Andrew Victor is no longer maintaining at91.  Instead, Alexandre
     Belloni now becomes an official maintainer, after having done a
     bulk of the work for a while.

   - Baruch Siach, who added the mach-digicolor platform in 4.1 is now
     listed as maintainer

   - The git URL for mach-socfpga has changed

  Bug fixes:

   - Three bug fixes for new rockchip rk3288 code

   - A regression fix to make SD card support work on certain ux500
     boards

   - multiple smaller dts fixes for imx, omap, mvebu, and shmobile

   - a regression fiix for omap3 power consumption

   - a fix for regression in the ARM CCI bus driver

  Configuration changes:

   - more imx platforms are now enabled in multi_v7_defconfig"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (39 commits)
  MAINTAINERS: add Conexant Digicolor machines entry
  MAINTAINERS: socfpga: update the git repo for SoCFPGA
  ARM: multi_v7_defconfig: Select more FSL SoCs
  MAINTAINERS: replace an AT91 maintainer
  drivers: CCI: fix used_mask init in validate_group()
  bus: omap_l3_noc: Fix master id address decoding for OMAP5
  bus: omap_l3_noc: Fix offset for DRA7 CLK1_HOST_CLK1_2 instance
  ARM: dts: dra7: Fix efuse register size for ABB
  ARM: dts: am57xx-beagle-x15: Switch GPIO fan number
  ARM: dts: am57xx-beagle-x15: Switch UART mux pins
  ARM: dts: am437x-sk: reduce col-scan-delay-us
  ARM: dts: am437x-sk: fix for new newhaven display module revision
  ARM: dts: am57xx-beagle-x15: Fix RTC aliases
  ARM: dts: am57xx-beagle-x15: Fix IRQ type for mcp7941x
  ARM: dts: omap3: Add #iommu-cells to isp and iva iommu
  ARM: omap2plus_defconfig: Enable EXTCON_USB_GPIO
  ARM: dts: OMAP3-N900: Add microphone bias voltages
  ARM: OMAP2+: Fix omap off idle power consumption creeping up
  MAINTAINERS: Update brcmstb entry
  MAINTAINERS: Remove Christian Daudt for mach-bcm
  ...

Pull user-namespace fix from Eric Biederman:
 "Eric Windish recently reported a really bug that allows mounting fresh
  copies of proc and sysfs when it really should not be allowed.  The
  code attempted to verify that proc and sysfs were fully visible but
  there is a test missing to ensure that the root of the filesystem is
  visible.  Doh!

  The following patch fixes that.

  This fixes a containment issue that the docker folks are seeing"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  mnt: Fix fs_fully_visible to verify the root directory is visible

Pull irq updates from Thomas Gleixner:
 "Two patches from the irq departement:

   - a simple fix to make dummy_irq_chip usable for wakeup scenarios

   - removal of the gic arch_extn hackery.  Now that all users are
     converted we really want to get rid of the interface so people wont
     come up with new use cases"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: gic: Drop support for gic_arch_extn
  genirq: Set IRQCHIP_SKIP_SET_WAKE flag for dummy_irq_chip

Pull timer fix from Thomas Gleixner:
 "A simple fix to actually shut down a detached device instead of
  keeping it active"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clockevents: Shutdown detached clockevent device

We cast away the volatile, but really, why make it volatile at all?
We already do a mb() inside the cpumask_empty() loop.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes a dumb bug in fs_fully_visible that allows proc or sys to
be mounted if there is a bind mount of part of /proc/ or /sys/ visible.

Cc: stable@vger.kernel.org
Reported-by: NEric Windisch <ewindisch@docker.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Pull vfs fixes from Al Viro:
 "A couple of fixes for bugs caught while digging in fs/namei.c.  The
  first one is this cycle regression, the second is 3.11 and later"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  path_openat(): fix double fput()
  namei: d_is_negative() should be checked before ->d_seq validation

path_openat() jumps to the wrong place after do_tmpfile() - it has
already done path_cleanup() (as part of path_lookupat() called by
do_tmpfile()), so doing that again can lead to double fput().

Cc: stable@vger.kernel.org	# v3.11+
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fetching ->d_inode, verifying ->d_seq and finding d_is_negative() to
be true does *not* mean that inode we'd fetched had been NULL - that
holds only while ->d_seq is still unchanged.

Shift d_is_negative() checks into lookup_fast() prior to ->d_seq
verification.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull btrfs fix from Chris Mason:
 "When an arm user reported crashes near page_address(page) in my new
  code, it became clear that I can't be trusted with GFP masks.  Filipe
  beat me to the patch, and I'll just be in the corner with my dunce cap
  on"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong mapping flags for free space inode

Pull device mapper fixes from Mike Snitzer:
 "Two additional fixes for changes introduced via DM during the 4.1
  merge window.

  The first reverts a dm-crypt change that wasn't correct.  The second
  fixes a device format regression that impacted userspace"

* tag 'dm-4.1-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  init: fix regression by supporting devices with major:minor:offset format
  Revert "dm crypt: fix deadlock when async crypto algorithm returns -EBUSY"

Pull block fixes from Jens Axboe:
 "A collection of fixes since the merge window;

   - fix for a double elevator module release, from Chao Yu.  Ancient bug.

   - the splice() MORE flag fix from Christophe Leroy.

   - a fix for NVMe, fixing a patch that went in in the merge window.
     From Keith.

   - two fixes for blk-mq CPU hotplug handling, from Ming Lei.

   - bdi vs blockdev lifetime fix from Neil Brown, fixing and oops in md.

   - two blk-mq fixes from Shaohua, fixing a race on queue stop and a
     bad merge issue with FUA writes.

   - division-by-zero fix for writeback from Tejun.

   - a block bounce page accounting fix, making sure we inc/dec after
     bouncing so that pre/post IO pages match up.  From Wang YanQing"

* 'for-linus' of git://git.kernel.dk/linux-block:
  splice: sendfile() at once fails for big files
  blk-mq: don't lose requests if a stopped queue restarts
  blk-mq: fix FUA request hang
  block: destroy bdi before blockdev is unregistered.
  block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE
  elevator: fix double release of elevator module
  writeback: use |1 instead of +1 to protect against div by zero
  blk-mq: fix CPU hotplug handling
  blk-mq: fix race between timeout and CPU hotplug
  NVMe: Fix VPD B0 max sectors translation

Pull GPIO fixes from Linus Walleij:
 "Here is a bunch of GPIO fixes that I collected since -rc1, nothing
  controversial, nothing special:

   - fix a memory leak for GPIO hotplug.

   - fix a signedness bug in the ACPI GPIO pin validation.

   - driver fixes: Qualcomm SPMI and OMAP MPUIO IRQ issues"

* tag 'gpio-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: omap: Fix regression for MPUIO interrupts
  gpio: sysfs: fix memory leaks and device hotplug
  pinctrl: qcom-spmi-gpio: Fix input value report
  pinctrl: qcom-spmi-gpio: Fix output type configuration
  gpiolib: change gpio pin from unsigned to signed in acpi callback

Pull MMC fixes from Ulf Hansson:
 "MMC core:
   - Don't access RPMB partitions for normal read/write
   - Fix hibernation restore sequence

  MMC host:
   - dw_mmc: Fix card detection for non removable cards
   - dw_mmc: Fix sglist issue in 32-bit mode
   - sh_mmcif: Fix timeout value for command request"

* tag 'mmc-4.1-rc2' of git://git.linaro.org/people/ulf.hansson/mmc:
  mmc: dw_mmc: dw_mci_get_cd check MMC_CAP_NONREMOVABLE
  mmc: dw_mmc: init desc in dw_mci_idmac_init
  mmc: card: Don't access RPMB partitions for normal read/write
  mmc: sh_mmcif: Fix timeout value for command request
  mmc: core: add missing pm event in mmc_pm_notify to fix hib restore

Merge tag 'trace-fixes-v4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "The newly added ftrace_print_array_seq() function had a bug in it.
  Luckily, the only user of it didn't make the 4.1 merge window.

  But the helper function should be fixed before 4.2 when the users
  start coming in"

* tag 'trace-fixes-v4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Make ftrace_print_array_seq compute buf_len

The Marvell mwifiex driver prevents the system to enter into a suspend
state if the card power is not preserved during a suspend/resume cycle.

So Suspend-to-RAM and Suspend-to-idle are failing on Exynos5250 Snow.

Add the keep-power-in-suspend Power Management property to the SDIO/MMC
node so the mwifiex suspend handler doesn't fail and the system is able
to enter into a suspend state.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NKukjin Kim <kgene@kernel.org>

Remove the extra zero in the "cpu-crit-0" trip point for exynos5420
and exynos5440.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: NKukjin Kim <kgene@kernel.org>

The Exynos4412 SoC has a s3c6410 RTC where the source clock
is now a mandatory property.
This patch fixes probe failure of s3c-rtc on Odroid-X2/U2/U3 boards.
Signed-off-by: NMarkus Reichl <m.reichl@fivetechno.de>
Tested-by: NTobias Jakobi <tjakobi@math.uni-bielefeld.de>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NKukjin Kim <kgene@kernel.org>

Commit ea08de16 ("ARM: dts: Add DISP1 power domain for exynos5420")
added a device node for the Exynos5420 DISP1 power domain but dit not
make the DP controller a consumer of that power domain.

This causes an "Unhandled fault: imprecise external abort" error if the
exynos-dp driver tries to access the DP controller registers and the PD
was turned off. This lead to a kernel panic and a complete system hang.

Make the DP controller device node a consumer of the DISP1 power domain
to ensure that the PD is turned on when the exynos-dp driver is probed.

Fixes: ea08de16 ("ARM: dts: Add DISP1 power domain for exynos5420")
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NKukjin Kim <kgene@kernel.org>

This adds Baruch as the maintainer for the Digicolor platform.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The git tree at rocketboards.org is going away. Update the entry to reflect
the address of the new location. Also add an entry for all the socfpga_*
dts files.
Signed-off-by: NDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Tegra would not only need a hardware vblank counter that
increments at leading edge of vblank, but also support
for instantaneous high precision vblank timestamp queries, ie.
a proper implementation of dev->driver->get_vblank_timestamp().

Without these, there can be off-by-one errors during vblank
disable/enable if the scanout is inside vblank at en/disable
time, and additionally clients will never see any useable
vblank timestamps when querying via drmWaitVblank ioctl. This
would negatively affect swap scheduling under X11 and Wayland.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>