Split update plane in two parts, an initial check part that can fail
and the update part that can't fail.

This is a important step for the upcoming atomic modesetting support.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

It is no longer used anywhere.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

We can safely use the mode stored in the crtc.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

exynos_drm_manager was just a redundant struct to represent the crtc as
well. In this commit we merge exynos_drm_manager into exynos_drm_crtc to
remove an unnecessary level of indirection easing the understand of the
flow on exynos.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

manager-drm_dev is only accessed by exynos_drm_crtc_create() so this patch
pass drm_dev as argument on exynos_drm_crtc_create() and remove it from
struct exynos_drm_manager.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

'type' is now part of the struct exynos_drm_crtc. This is just another
step in the struct exynos_drm_manager removal.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

It is not longer used. This is part of the process of removing
struct exynos_drm_manager entirely.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

Get the pipe value from a parameter instead of getting it from
manager->pipe. We are removing manager->pipe.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

'base' is more widely used name in the drm subsystem for the base object.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

This was just as extra chain in the call stack. We just rename it to
_set_base() and let it do everything alone.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

Avoid an extra call to exynos_drm_crtc_mode_set_commit() that only calls
exynos_update_plane().
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

We can safely use the exynos_update_plane() to update the plane
framebuffer for both the overlay and primary planes.

Note that this patch removes a call to manager->ops->commit() in
exynos_drm_crtc_mode_set_commit(). The commit() call is used only by the
fimd driver to set underlying timings and need only in full modeset
operations. For plane update only win_commit is needed.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

It's doing nothing but calling exynos_crtc->ops->win_commit(), so let's
call this directly to avoid extra layers of abstraction.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

DPMS only makes sense when the mode changes, for plane update changes do
not perform any dpms operation.

This move places the win_commit() and commit() calls directly in the code
instead of calling exynos_drm_crtc_commit() thus avoiding DPMS operations.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

DPMS settings should only be changed by a full modeset.
exynos_plane_update() should only care about updating the planes itself
and nothing else.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

vidi_commit does nothing, remove it and its callers.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

We  set it in the beginning of the function, thus no need to set it at
initialization.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

struct exynos_drm_overlay has no practical advantage nor serves as
important piece of the exynos API design. The only place it was used
was inside the struct exynos_plane which was just causing a extra
access overhead. Users had to access the overlay first and just then
get the plane information it contains.

This patch merges struct exynos_drm_overlay into struct exynos_plane.
It also renames struct exynos_plane to struct exynos_drm_plane.

The rational is to cut one step to access plane information.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

This functions were doing nothing but calling a manager op function,
so remove them and call the manager directly.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

Let other pieces of the driver access struct exynos_drm_crtc as well.

struct exynos_drm_manager will be merged into struct exynos_drm_crtc, in
the sense we will move all its members to exynos_drm_crtc, so to start
this conversion exynos_drm_crtc need to be exposed as well.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

With this change we allow other pieces of the code to use this macro.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

Backmerge Linus tree after rc5 + drm-fixes went in.

There were a few amdkfd conflicts I wanted to avoid,
and Ben requested this for nouveau also.

Conflicts:
	drivers/gpu/drm/amd/amdkfd/Makefile
	drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
	drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager.c
	drivers/gpu/drm/amd/amdkfd/kfd_priv.h
	drivers/gpu/drm/amd/include/kgd_kfd_interface.h
	drivers/gpu/drm/i915/intel_runtime_pm.c
	drivers/gpu/drm/radeon/radeon_kfd.c

Merge branch 'drm-sti-next-add-dvo' of git://git.linaro.org/people/benjamin.gaignard/kernel into drm-next

This patch enable the last big hardware feature of my driver: the
connector for panel.
Like for HMDI and HDA, Digital Video Out (DVO) create brige, encoder
and connector
drm objects.

* 'drm-sti-next-add-dvo' of git://git.linaro.org/people/benjamin.gaignard/kernel:
  drm: sti: add DVO output connector

Add atmel HLCDC driver.

* tag 'atmel-hlcdc-drm-3.20' of https://github.com/bbrezillon/linux-at91:
  drm: add DT bindings documentation for atmel-hlcdc-dc driver
  drm: add Atmel HLCDC Display Controller support
  drm: panel: simple-panel: add bus format information for foxlink panel
  drm: panel: simple-panel: add support for bus_format retrieval
  drm: add bus_formats and num_bus_formats fields to drm_display_info

- Infrastructure work in amdkfd to prepare for VI support. This work mainly
  includes separating modules into ASIC-specific functionality, adding
  new properties that are relevant for VI, making sure that shared code is
  reused, etc.

- Improve mechanism of submitting packets to HIQ (the kernel queue that amdkfd
  uses to issue commands to the GPU). The driver used to verify that each CS
  was read by the GPU. However, this proved to be both unnecessary and erroneous.
  Therefore, we cancelled this verification.

- Moved initialization of compute VMIDs into radeon driver

- Various minor fixes

* tag 'drm-amdkfd-next-2015-01-21' of git://people.freedesktop.org/~gabbayo/linux: (22 commits)
  drm/amdkfd: Fix description of sched_policy module parameter
  drm/amdkfd: Remove sync_with_hw() from amdkfd
  drm/amdkfd: Remove unused function busy_wait()
  drm/amdkfd: Replace cpu_relax() with schedule() in DQM
  drm/amdkfd: Fix for-loop when allocating HQD (non-HWS)
  drm/amdkfd: Add initial VI support for KQ
  drm/amdkfd: Encapsulate KQ functions in ops structure
  drm/amdkfd: Add initial VI support for DQM
  drm/amdkfd: Encapsulate DQM functions in ops structure
  drm/amdkfd: Don't BUG on freeing GART sub-allocation
  drm/amdkfd: Fix logic of destroy_queue_nocpsch()
  MAINTAINERS: Update amdkfd files
  drm/amdkfd: Change MQD manager to be H/W specific
  drm/amdkfd: Add asic property to kfd_device_info
  drm/amdkfd: Make KFD_MQD_TYPE enum types H/W agnostic
  drm/amdkfd: Add new VI-specific queue properties
  drm/radeon: Use new cik_structs.h file
  drm/amdkfd: Don't include header files from radeon
  drm/amd: Put cik structures in a common place
  drm/radeon: Don't use relative paths in #include
  ...

Pull superh tracing fix from Steven Rostedt:
 "It's been reported that function tracing does not work on the sh
  architecture because gcc 4.8 for superH does not support -m32, and the
  recordmcount.pl script adds "-m32" when re-compiling the object files
  with the mcount locations.

  I was not able to reproduce this problem, as it seems that -m32 works
  fine for my cross compiler gcc 4.6.3, but I have to assume that -m32
  was deprecated somewhere between 4.6 and 4.8.  As it still seems to
  compile fine without -m32, I have no reason not to add this patch, as
  having -m32 seems to cause trouble for others"

* tag 'trace-sh-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  scripts/recordmcount.pl: There is no -m32 gcc option on Super-H anymore

The Atmel HLCDC (HLCD Controller) IP available on some Atmel SoCs (i.e.
at91sam9n12, at91sam9x5 family or sama5d3 family) provides a display
controller device.

The HLCDC block provides a single RGB output port, and only supports LCD
panels connection to LCD panels for now.

The atmel,panel property link the HLCDC RGB output with the LCD panel
connected on this port (note that the HLCDC RGB connector implementation
makes use of the DRM panel framework).

Connection to other external devices (DRM bridges) might be added later by
mean of a new atmel,xxx (atmel,bridge) property.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

The Atmel HLCDC (HLCD Controller) IP available on some Atmel SoCs (i.e.
at91sam9n12, at91sam9x5 family or sama5d3 family) provides a display
controller device.

This display controller supports at least one primary plane and might
provide several overlays and an hardware cursor depending on the IP
version.

At the moment, this driver only implements an RGB connector to interface
with LCD panels, but support for other kind of external devices might be
added later.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Tested-by: Anthony Harivel <anthony.harivel@emtrion.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Foxlink's fl500wvr00-a0t supports RGB888 format.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Thierry Reding <treding@nvidia.com>

Provide a way to specify panel requirement in terms of supported media bus
format (particularly useful for panels connected to an RGB or LVDS bus).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Thierry Reding <treding@nvidia.com>

Add bus_formats and num_bus_formats fields and
drm_display_info_set_bus_formats helper function to specify the bus
formats supported by a given display.

This information can be used by display controller drivers to configure
the output interface appropriately (i.e. RGB565, RGB666 or RGB888 on raw
RGB or LVDS busses).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Thierry Reding <treding@nvidia.com>

Pull sound fixes from Takashi Iwai:
 "This batch contains two fixes for FireWire lib module and a quirk for
  yet another Logitech WebCam.  The former is the fixes for MIDI
  handling I forgot to pick up during the merge window.  All the fixed
  code is pretty local and shouldn't give any regressions"

* tag 'sound-3.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: Add mic volume fix quirk for Logitech Webcam C210
  ALSA: firewire-lib: limit the MIDI data rate
  ALSA: firewire-lib: remove rx_blocks_for_midi quirk

Pull drm fixes from Dave Airlie:
 "Just back from LCA + some days off, had some fixes from the past 2 weeks,

  Some amdkfd code removal for a feature that wasn't ready, otherwise
  just one fix for core helper sleeping, exynos, i915, and radeon fixes.

  I thought I had some sti fixes but they were already in, and it
  confused me for a few mins this morning"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm: fb helper should avoid sleeping in panic context
  drm/exynos: fix warning of vblank reference count
  drm/exynos: remove unnecessary runtime pm operations
  drm/exynos: fix reset codes for memory mapped hdmi phy
  drm/radeon: use rv515_ring_start on r5xx
  drm/radeon: add si dpm quirk list
  drm/radeon: don't print error on -ERESTARTSYS
  drm/i915: Fix mutex->owner inspection race under DEBUG_MUTEXES
  drm/i915: Ban Haswell from using RCS flips
  drm/i915: vlv: sanitize RPS interrupt mask during GPU idling
  drm/i915: fix HW lockup due to missing RPS IRQ workaround on GEN6
  drm/i915: gen9: fix RPS interrupt routing to CPU vs. GT
  drm/exynos: remove the redundant machine checking code
  drm/radeon: add a dpm quirk list
  drm/amdkfd: Fix sparse warning (different address space)
  drm/radeon: fix VM flush on CIK (v3)
  drm/radeon: fix VM flush on SI (v3)
  drm/radeon: fix VM flush on cayman/aruba (v3)
  drm/amdkfd: Drop interrupt SW ring buffer

Pull MFD fixes from Lee Jones:
 - Avoid platform ID collision in da9052
 - Skip caching volatile registers in tps65218
 - Use correct address base in tps65218
 - Repair deadlock on suspend in rtsx_usb

* tag 'mfd-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
  mfd: rtsx_usb: Fix runtime PM deadlock
  mfd: tps65218: Make INT1 our status_base register
  mfd: tps65218: Make INT[12] and STATUS registers volatile
  mfd: da9052-core: Fix platform-device id collision

imx-drm mode fixup support, imx-hdmi bridge conversion and imx-drm cleanup

- Implement mode_fixup for a DI vertical timing limitation
- Use generic DRM OF helpers in DRM core
- Convert imx-hdmi to dw_hdmi drm_bridge and add rockchip
  driver
- Add DC use counter to fix multi-display support
- Simplify handling of DI clock flags
- A few small fixes and cleanup

* tag 'imx-drm-next-2015-01-09' of git://git.pengutronix.de/git/pza/linux: (26 commits)
  imx-drm: core: handling of DI clock flags to ipu_crtc_mode_set()
  gpu: ipu-di: Switch to DIV_ROUND_CLOSEST for DI clock divider calc
  gpu: ipu-v3: Use videomode in struct ipu_di_signal_cfg
  imx-drm: encoder prepare/mode_set must use adjusted mode
  imx-drm: ipuv3-crtc: Implement mode_fixup
  drm_modes: add drm_display_mode_to_videomode
  gpu: ipu-di: remove some non-functional code
  gpu: ipu-di: Add ipu_di_adjust_videomode()
  drm: rockchip: export functions needed by rockchip dw_hdmi bridge driver
  drm: bridge/dw_hdmi: request interrupt only after initializing the mutes
  drm: bridge/dw_hdmi: add rockchip rk3288 support
  dt-bindings: Add documentation for rockchip dw hdmi
  drm: bridge/dw_hdmi: add function dw_hdmi_phy_enable_spare
  drm: bridge/dw_hdmi: clear i2cmphy_stat0 reg in hdmi_phy_wait_i2c_done
  drm: bridge/dw_hdmi: add mode_valid support
  drm: bridge/dw_hdmi: add support for multi-byte register width access
  dt-bindings: add document for dw_hdmi
  drm: imx: imx-hdmi: move imx-hdmi to bridge/dw_hdmi
  drm: imx: imx-hdmi: split phy configuration to platform driver
  drm: imx: imx-hdmi: convert imx-hdmi to drm_bridge mode
  ...

* 'drm/next/du' of git://linuxtv.org/pinchartl/fbdev:
  drm: rcar-du: Implement support for interlaced modes
  drm: rcar-du: Clamp DPMS states to on and off
  drm: rcar-du: Enable hotplug detection on HDMI connector
  drm: rcar-du: Output HSYNC instead of CSYNC
  drm: rcar-du: Add support for external pixel clock
  drm: rcar-du: Refactor DEFR8 feature
  drm: rcar-du: Remove LVDS and HDMI encoders chaining restriction
  drm: rcar-du: Configure pitch for chroma plane of multiplanar formats
  drm: rcar-du: Don't fail probe in case of partial encoder init error
  drm: adv7511: Remove interlaced mode check

- Add support for SDMA usermode queues
- Replace logic of sub-allocating from GART buffer in amdkfd. Instead
  of using radeon_sa module, use a new module that is more suited for
  this purpose
- Add the number of watch points to amdkfd topology
- Split a function that did two things into two seperate functions.

* tag 'drm-amdkfd-next-2015-01-09' of git://people.freedesktop.org/~gabbayo/linux:
  drm/amd: Remove old radeon_sa funcs from kfd-->kgd interface
  drm/radeon: Remove old radeon_sa usage from kfd-->kgd interface
  drm/amdkfd: Using new gtt sa in amdkfd
  drm/amdkfd: Allocate gart memory using new interface
  drm/amdkfd: Fixed calculation of gart buffer size
  drm/amdkfd: Add kfd gtt sub-allocator functions
  drm/amdkfd: Add gtt sa related data to kfd_dev struct
  drm/radeon: Impl. new gtt allocate/free functions
  drm/amd: Add new kfd-->kgd interface for gart usage
  drm/radeon: Enable sdma preemption
  drm/amdkfd: Pass queue type to pqm_create_queue()
  drm/amdkfd: Identify SDMA queue in create queue ioctl
  drm/amdkfd: Add SDMA user-mode queues support to QCM
  drm/amdkfd: Add SDMA mqd support
  drm/radeon: Implement SDMA interface functions
  drm/amd: Add SDMA functions to kfd-->kgd interface
  drm/amdkfd: Process-device data creation and lookup split
  drm/amdkfd: Add number of watch points to topology

Merge tag 'drm-amdkfd-fixes-2015-01-13' of git://people.freedesktop.org/~gabbayo/linux into drm-fixes

- Remove the interrupt SW ring buffer impl. as it is not used by any module
  in amdkfd.

- Fix a sparse warning

* tag 'drm-amdkfd-fixes-2015-01-13' of git://people.freedesktop.org/~gabbayo/linux:
  drm/amdkfd: Fix sparse warning (different address space)
  drm/amdkfd: Drop interrupt SW ring buffer

misc i915 fixes

* tag 'drm-intel-fixes-2015-01-15' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Fix mutex->owner inspection race under DEBUG_MUTEXES
  drm/i915: Ban Haswell from using RCS flips
  drm/i915: vlv: sanitize RPS interrupt mask during GPU idling
  drm/i915: fix HW lockup due to missing RPS IRQ workaround on GEN6
  drm/i915: gen9: fix RPS interrupt routing to CPU vs. GT

There are still some places in the fb helper that need to avoid
sleeping in panic context. Here's an example:

[   65.615496] bad: scheduling from the idle thread!
[   65.620747] CPU: 92 PID: 0 Comm: swapper/92 Tainted: G   M        E  3.18.0-rc4-7-default+ #20

[   65.630364] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS
BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
[   65.641923]  ffff88087f693d80 ffff88087f689878 ffffffff81566db9 0000000000000000
[   65.650226]  ffff88087f693d80 ffff88087f689898 ffffffff810871ff ffff88046eb3e0d0
[   65.658527]  ffff88087f693d80 ffff88087f6898c8 ffffffff8107c1fa 000000017f6898b8
[   65.666830] Call Trace:
[   65.669557]  <#MC>  [<ffffffff81566db9>] dump_stack+0x46/0x58
[   65.675994]  [<ffffffff810871ff>] dequeue_task_idle+0x2f/0x40
[   65.682412]  [<ffffffff8107c1fa>] dequeue_task+0x5a/0x80
[   65.688345]  [<ffffffff810804f3>] deactivate_task+0x23/0x30
[   65.694569]  [<ffffffff81569050>] __schedule+0x580/0x7f0
[   65.700502]  [<ffffffff81569739>] schedule_preempt_disabled+0x29/0x70
[   65.707696]  [<ffffffff8156abb6>] __ww_mutex_lock_slowpath+0xb8/0x162
[   65.714891]  [<ffffffff8156acb3>] __ww_mutex_lock+0x53/0x85
[   65.721125]  [<ffffffffa00b3a5d>] drm_modeset_lock+0x3d/0x110 [drm]
[   65.728132]  [<ffffffffa00b3c2a>] __drm_modeset_lock_all+0x8a/0x120 [drm]
[   65.735721]  [<ffffffffa00b3cd0>] drm_modeset_lock_all+0x10/0x30 [drm]
[   65.743015]  [<ffffffffa01af8bf>] drm_fb_helper_pan_display+0x2f/0xf0 [drm_kms_helper]
[   65.751857]  [<ffffffff8132bd21>] fb_pan_display+0xd1/0x1a0
[   65.758081]  [<ffffffff81326010>] bit_update_start+0x20/0x50
[   65.764400]  [<ffffffff813259f2>] fbcon_switch+0x3a2/0x550
[   65.770528]  [<ffffffff813a01c9>] redraw_screen+0x189/0x240
[   65.776750]  [<ffffffff81322f8a>] fbcon_blank+0x20a/0x2d0
[   65.782778]  [<ffffffff8137d359>] ? erst_writer+0x209/0x330
[   65.789002]  [<ffffffff810ba2f3>] ? internal_add_timer+0x63/0x80
[   65.795710]  [<ffffffff810bc137>] ? mod_timer+0x127/0x1e0
[   65.801740]  [<ffffffff813a0cd8>] do_unblank_screen+0xa8/0x1d0
[   65.808255]  [<ffffffff813a0e10>] unblank_screen+0x10/0x20
[   65.814381]  [<ffffffff812ca0d9>] bust_spinlocks+0x19/0x40
[   65.820508]  [<ffffffff81561ca7>] panic+0x106/0x1f5
[   65.825955]  [<ffffffff8102336c>] mce_panic+0x2ac/0x2e0
[   65.831789]  [<ffffffff812c796a>] ? delay_tsc+0x4a/0x80
[   65.837625]  [<ffffffff81024e1f>] do_machine_check+0xbaf/0xbf0
[   65.844138]  [<ffffffff813365d7>] ? intel_idle+0xc7/0x150
[   65.850166]  [<ffffffff8156f03f>] machine_check+0x1f/0x30
[   65.856195]  [<ffffffff813365d7>] ? intel_idle+0xc7/0x150
[   65.862222]  <<EOE>>  [<ffffffff814283d5>] cpuidle_enter_state+0x55/0x170
[   65.869823]  [<ffffffff814285a7>] cpuidle_enter+0x17/0x20
[   65.875852]  [<ffffffff81097b08>] cpu_startup_entry+0x2d8/0x370
[   65.882467]  [<ffffffff8102fe29>] start_secondary+0x159/0x180

There's __drm_modeset_lock_all() which Daniel Vetter introduced for this
purpose. We can leverage that without reinventing anything. This patch
works with the latest kernel.
Reviewed-by: Rob Clark <robdclark@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>