There are no more users, byebye!
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is now done completely atomically.
Keep connectors_active for now, but make it mirror crtc_state->active.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

First step in removing dpms and validating atomic state.

There can still be a mismatch in the connector state because the dpms
callbacks are still used, but this can not happen immediately after a modeset.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Due to the way busy_bits was handled, we were not doing any flushes if
we didn't previously get an invalidate. Since it's possible to get
flushes without an invalidate first, remove the busy_bits early
return.

So now that we don't have the busy_bits guard anymore we'll need the
origin check for the GTT tracking (we were not doing anything on GTT
flushes due to the GTT check at invalidate()).

As a last detail, since we can get multiple consecutive flushes,
disable FBC before updating it, otherwise intel_fbc_update() will just
keep FBC enabled instead of restarting it.

Notice that this does not fix any of the current IGT tests due to the
fact that we still have a few intel_fbc() calls at points where we
also have the frontbuffer tracking calls: we didn't fully convert to
frontbuffer tracking yet. Once we remove those calls and start relying
only on the frontbuffer tracking infrastructure we'll need this patch.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is required to properly handle failing dpms calls.
When making a wait in i915 interruptible, I've noticed
that the dpms sequence could fail with -ERESTARTSYS because
it was waiting interruptibly for flips. So from now on
allow drivers to fail in their connector dpms callback.

Encoder and crtc dpms callbacks are unaffected.

Changes since v1:
- Update kerneldoc for the drm helper functions.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Resolve conflicts due to different merge order.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the CRC PWM device in intel_panel.c and add new MIPI backlight
specififc callbacks

v2: Modify to use pwm_config callback
v3: Addressed Jani's comments
    - Renamed all function as pwm_* instead of vlv_*
    - Call intel_panel_actually_set_backlight in enable function
    - Return -ENODEV in case pwm_get fails
    - in case pwm_config error return error cdoe from pwm_config
    - Cleanup pwm in intel_panel_destroy_backlight
v4: Removed unused #defines and initialized backlight with INVALID_PIPE (Ville)

CC: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we both set mode->private_flags to some value and also use
the pipe_config quirk. But since the pipe_config quirk isn't tied to
the lifetime of the mode object we need to check both.

Simplify this by only using mode.private_flags and stop using the
INHERITED_MODE quirk. Also for clarity add an explicit #define for
that driver priavete mode flag.

By using crtc_state->mode_changed we can also remove the recalc local
variable.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This can only fail because of a bug in the code.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Squash in follow-up to also remove start_vbl_count from
intel_crtc->atomic and put it into the intel_crtc directly - it's not
precomputed state.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Huzzah! \o/
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Calculate all state using a normal transition, but afterwards fudge
crtc->state->active back to its old value. This should still allow
state restore in setup_hw_state to work properly.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The previous commit converted hw readout to atomic, all the new_*
members were used for restoring the old state, but with the
conversion of suspend to atomic there's no use left for them.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

All non-primary planes get disabled during hw readout,
this reduces complexity and means not having to do some plane
visibility checks during the first commit.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Nothing depends on this outside initial hw readout, so keep this
struct on the stack instead.

Changes since v1:
- Remove unrelated changes.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There's not much point for calculating the changes for the old
state. Instead just disable all scalers when disabling. It's
probably good enough to just disable the crtc_scaler, but just in
case there's a bug disable all scalers.

This means intel_atomic_setup_scalers is only called in the crtc
check function now, so all the transitional code can be removed.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So make it static.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since flush actually means invalidate + flush we need to force psr
exit on PSR flush.

On Core platforms there is no way to disable hw tracking and
do the pure sw tracking so we simulate it by fully disable psr and
reschedule a enable back.
So a good idea is to minimize sequential disable/enable in cases we
know that HW tracking like when flush has been originated by a flip.
Also flip had just invalidated it already.

It also uses origin to minimize the a bit the amount of
disable/enabled, mainly when flip already had invalidated.

With this patch in place it is possible to do a flush on dirty areas
properly in a following patch.

v2: Remove duplicated exit on HSW+Sprites as pointed out by Paulo.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This will be useful to PSR and FBC once we start making
dirty fb calls to also flush frontbuffer.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because the cool kids use dev_priv and FBC wants to be cool too.

We've been historically using struct drm_device on the FBC function
arguments, but we only really need it for intel_vgpu_active(): we can
use dev_priv everywhere else. So let's fully switch to dev_priv since
I'm getting tired of adding "struct drm_device *dev = dev_priv->dev"
everywhere.

If I get a NACK here I'll propose the opposite: convert all the
functions that currently take dev_priv to take dev.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make sure we're not going to have weird races in really weird cases
where a lot of different CRTCs are doing rendering and modesets at the
same time.

With this change and the stolen_lock from the previous patch, we can
start removing the struct_mutex locking we have around FBC in the next
patches.

v2:
 - Rebase (6 months later)
 - Also lock debugfs and stolen.
v3:
 - Don't lock a single value read (Chris).
 - Replace lockdep assertions with WARNs (Daniel).
 - Improve commit message.
 - Don't forget intel_pre_plane_update() locking.
v4:
 - Don't remove struct_mutex at intel_pre_plane_update() (Chris).
 - Add comment regarding locking dependencies (Chris).
 - Rebase after the stolen code rework.
 - Rebase again after drm-intel-nightly changes.
v5:
 - Rebase after the new stolen_lock patch.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v4)
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the abstractions created by the last patch, we can move this code
and the only thing inside intel_fbc.c that knows about dev_priv->mm is
the code that reads stolen_base.

We also had to move a call to i915_gem_stolen_cleanup_compression()
- now called intel_fbc_cleanup_cfb() - outside i915_gem_stolen.c.

v2:
  - Rebase after the remove_node() changes on the previous patch.
Requested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Depending on the platform the port clock fed to the pipe can be the PLL's
post-divided fast clock rate or a /5 divided version of it. To make this
more obvious across the platforms calculate this port clock along with
the rest of the PLL parameters.

This is also needed by the next patch where we can reuse the CHV helper
for the BXT PLL HW readout code; so export the corresponding helper.

While at it also add a more descriptive name to the helpers and a
comment explaining what's being calculated.

No functional change.
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds support for 0.85V VccIO on Skylake Y,
separate buffer translation tables for Skylake U,
and support for I_boost for the entries that needs this.

Changes in v2:
* Refactored the code a bit to move all DDI signal level setup to
  intel_ddi.c

Issue: VIZ-5677
Signed-off-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Reviewed-by: NAntti Koskipää <antti.koskipaa@linux.intel.com>
[danvet: Apply style polish checkpatch suggested.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CxSR (or maxfifo on VLV/CHV) blocks somne changes to the plane control
register (enable bit at least, not quite sure about the rest). So in
order to have the plane enable/disable when we want we need to first
kick the hardware out of cxsr.

Unfortunateloy this requires some extra vblank waits. For the CxSR
enable after the plane update we should eventually use an async
vblank worker, but since we don't have that just do sync vblank
waits. For the disable case we have no choice but to do it
synchronously.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NClint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Turns out the VLV/CHV system agent doesn't understand memory
latencies, so trying to rely on the PND deadline mechanism is not
going to fly especially when DDR DVFS is enabled. Currently we try to
avoid the problems by lying to the system agent about the deadlines
and setting the FIFO watermarks to 8 cachelines. This however leads to
bad memory self refresh residency.

So in order to satosfy everyone we'll just give up on the deadline
scheme and program the watermarks old school based on the worst case
memory latency.

I've modelled this a bit on the ILK+ approach where we compute multiple
sets of watermarks for each pipe (PM2,PM5,DDR DVFS) and when merge thet
appropriate one later with the watermarks from other pipes. There isn't
too much to merge actually since each pipe has a totally independent
FIFO (well apart from the mess with the partially shared DSPARB
registers), but still decopuling the pipes from each other seems like a
good idea.

Eventually we'll want to perform the watermark update in two phases
around the plane update to avoid underruns due to the single buffered
watermark registers. But that's still in limbo for ILK+ too, so I've not
gone that far yet for VLV/CHV either.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NClint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Read out the current watermark settings from the hardware at driver init
time. This will allow us to compare the newly calculated values against
the currrent ones and potentially avoid needless WM updates.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NClint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Try to update the watermarks on the right side of the plane update. This
is just a temporary hack until we get the proper two part update into
place. However in the meantime this might have some chance of at least
working.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NClint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We cannot let IPS enabled with no plane on the pipe:

BSpec: "IPS cannot be enabled until after at least one plane has
been enabled for at least one vertical blank." and "IPS must be
disabled while there is still at least one plane enabled on the
same pipe as IPS." This restriction apply to HSW and BDW.

However a shortcut path on update primary plane function
to make primary plane invisible by setting DSPCTRL to 0
was leting IPS enabled while there was no
other plane enabled on the pipe causing flickerings that we were
believing that it was caused by that other restriction where
ips cannot be used when pixel rate is greater than 95% of cdclok.

v2: Don't mess with Atomic path as pointed out by Ville.

v3: Rebase after a long time and atomic path changes.
    Accept Ville suggestion of not check !fb

v4: Re-factore on dinq

Reference: https://bugs.freedesktop.org/show_bug.cgi?id=85583
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NKenneth Graunke <kenneth@whitecape.org>
[danvet: Make it compile]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We cannot let IPS enabled with no plane on the pipe:

BSpec: "IPS cannot be enabled until after at least one plane has
been enabled for at least one vertical blank." and "IPS must be
disabled while there is still at least one plane enabled on the
same pipe as IPS." This restriction apply to HSW and BDW.

However a shortcut path on update primary plane function
to make primary plane invisible by setting DSPCTRL to 0
was leting IPS enabled while there was no
other plane enabled on the pipe causing flickerings that we were
believing that it was caused by that other restriction where
ips cannot be used when pixel rate is greater than 95% of cdclok.

v2: Don't mess with Atomic path as pointed out by Ville.

Reference: https://bugs.freedesktop.org/show_bug.cgi?id=85583
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Avoid some 'switch (plane->type)' by storing the fronbuffer_bits in
intel_plane.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: use singular frontbuffer_bits in intel_plane since a plan can
only ever have one bit. Discussed with Ville on irc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The frontbuffer code gives us accurate information about activity,
let's use it. Again this should avoid unecessary updates when multiple
screens are on.

Also realign function paramaters, I couldn't resist that bit of OCD.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The current/old frontbuffer might still have gpu frontbuffer rendering
pending. But once flipped it won't have the corresponding frontbuffer
bits any more and hence the request retire function won't ever clear
the corresponding busy bits. The async flip tracking (with the
flip_prepare and flip_complete functions) already does this, but
somehow I've forgotten to do this for synchronous flips.

Note that we don't track outstanding rendering of the new framebuffer
with busy_bits since all our plane update code waits for previous
rendering to complete before displaying a new buffer. Hence a new
buffer will never be busy.

v2: Drop the spurious inline Ville spotted.

v3: Don't touch flip_bits in the synchronsou frontbuffer_flip
function, noticed by Paulo.

v4: Remove one more inline that slipped through (Paulo).
Reported-by: NPaulo Zanoni <przanoni@gmail.com>
Cc: Paulo Zanoni <przanoni@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Testcase: igt/kms_frontbuffer_tracking/fbc-modesetfrombusy
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The plan is to pass requests around as the basic submission tracking structure
rather than rings and contexts. This patch updates the i915_gem_object_sync()
code path.

v2: Much more complex patch to share a single request between the sync and the
page flip. The _sync() function now supports lazy allocation of the request
structure. That is, if one is passed in then that will be used. If one is not,
then a request will be allocated and passed back out. Note that the _sync() code
does not necessarily require a request. Thus one will only be created until
certain situations. The reason the lazy allocation must be done within the
_sync() code itself is because the decision to need one or not is not really
something that code above can second guess (except in the case where one is
definitely not required because no ring is passed in).

The call chains above _sync() now support passing a request through which most
callers passing in NULL and assuming that no request will be required (because
they also pass in NULL for the ring and therefore can't be generating any ring
code).

The exeception is intel_crtc_page_flip() which now supports having a request
returned from _sync(). If one is, then that request is shared by the page flip
(if the page flip is of a type to need a request). If _sync() does not generate
a request but the page flip does need one, then the page flip path will create
its own request.

v3: Updated comment description to be clearer about 'to_req' parameter (Tomas
Elf review request). Rebased onto newer tree that significantly changed the
synchronisation code.

v4: Updated comments from review feedback (Tomas Elf)

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch doesn't have any functional change, but organize fruntbuffer
invalidate and busy by removing unecesarry signature argument for ring.

It was unsed on mark_fb_busy and only used on fb_obj_invalidate for the
same ORIGIN_CS usage. So let's clean it a bit

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The skylake scalers depend on the cdclk freq, but that frequency can
change during a modeset. So when a modeset happens calculate the new
cdclk in the atomic state. With the transitional helpers gone the
cached value can be used in the scaler, and committed after all
crtc's are disabled.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90874Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

By making color key atomic there are no more transitional helpers.
The plane check function will reject the color key when a scaler is
active.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Read out the initial state, and add a quirk to force add all planes
to crtc_state->plane_mask during initial commit. This will disable
all planes during the initial modeset.

The initial plane quirk is temporary, and will go away when hardware
readout is fully atomic, and the watermark updates in intel_sprite.c
are removed.

Changes since v1:
- Unset state->visible on !primary planes.
- Do not rely on the plane->crtc pointer in intel_atomic_plane,
  instead assume planes are invisible until modeset.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is probably intended to be be done during vblank evasion.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The idea was good, but planes can have a fb even though
they're disabled. This makes the force argument useless
and always true, because only the commit function updates
state.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

By passing crtc_state to the check_plane functions a lot of duplicated
code can be removed. There are still some transitional helper calls,
they will be removed later.

Changes since v1:
- Revert state->visible changes.
- Use plane->state->crtc instead of plane->crtc.
- Use drm_atomic_get_existing_crtc_state.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This makes it easier to verify that no changes are done when
calling this from crtc instead.

Changes since v1:
 - Make intel_wm_need_update static and always check it.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>