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>

Silence the following -Wmaybe-uninitialized warnings and make the code
more clear.

drivers/gpu/drm/i915/intel_display.c: In function ‘__intel_set_mode’:
drivers/gpu/drm/i915/intel_display.c:11844:14: warning: ‘crtc_state’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  return state->mode_changed || state->active_changed;
              ^
drivers/gpu/drm/i915/intel_display.c:11854:25: note: ‘crtc_state’ was declared here
  struct drm_crtc_state *crtc_state;
                         ^
drivers/gpu/drm/i915/intel_display.c:11868:6: warning: ‘crtc’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (crtc != intel_encoder->base.crtc)
      ^
drivers/gpu/drm/i915/intel_display.c:11853:19: note: ‘crtc’ was declared here
  struct drm_crtc *crtc;
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

The code in intel_crtc_restore_mode() sets the enabled value of all the
CRTCs when restoring the mode after a suspend/resume cycle. When more
than one CRTC is enabled, that causes drm_atomic_helper_check_modeset()
to fail if there is more than one pipe enabled, since all but one CRTC
has valid connector data. Instead, set only the enabled value for the
CRTC passed as an argument.

v2: Don't leak atomic state. (Matt)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90468
References: https://bugs.freedesktop.org/show_bug.cgi?id=90396Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>

The force restore path relies on the staged config to preserve the
configuration used before a suspend/resume cycle. The update done to it
in intel_modeset_fixup_state() would cause that information to be lost
after the first modeset, making it impossible to restore the modes for
pipes B and C.

References: https://bugs.freedesktop.org/show_bug.cgi?id=90468Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Since the force restore logic will restore the CRTCs state one at a
time, it is possible that the state will be inconsistent until the whole
operation finishes. A call to intel_modeset_check_state() is done once
it's over, so don't check the state multiple times in between. This
regression was introduced in:

commit 7f27126e
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Wed Nov 5 14:26:06 2014 -0800

    drm/i915: factor out compute_config from __intel_set_mode v3

v2: Rename check parameter to force_restore. (Matt)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94431
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Only bit 27 of SCRATCH1 and bit 6 of ROW_CHICKEN3 are allowed to be
set because of security-sensitive bits we don't want userspace to mess
with.  On HSW hardware the whitelisted bits control whether atomic
read-modify-write operations are performed on L3 or on GTI, and when
set to L3 (which can be 10x-30x better performing than on GTI,
depending on the application) require great care to avoid a system
hang, so we currently program them to be handled on GTI by default.

Beignet can immediately start taking advantage of this change to
enable L3 atomics.  Mesa should eventually switch to L3 atomics too,
but a number of non-trivial changes are still required so it will
continue using GTI atomics for now.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

In some cases it might be unnecessary or dangerous to give userspace
the right to write arbitrary values to some register, even though it
might be desirable to give it control of some of its bits.  This patch
extends the register whitelist entries to contain a mask/value pair in
addition to the register offset.  For registers with non-zero mask,
any LRM writes and LRI writes where the bits of the immediate given by
the mask don't match the specified value will be rejected.

This will be used in my next patch to grant userspace partial write
access to some sensitive registers.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Until now the software command checker assumed that commands could
read or write at most a single register per packet.  This is not
necessarily the case, MI_LOAD_REGISTER_IMM expects a variable-length
list of offset/value pairs and writes them in sequence.  The previous
code would only check whether the first entry was valid, effectively
allowing userspace to write unrestricted registers of the MMIO space
by sending a multi-register write with a legal first register, with
potential security implications on Gen6 and 7 hardware.

Fix it by extending the drm_i915_cmd_descriptor table to represent
multi-register access and making validate_cmd() iterate for all
register offsets present in the command packet.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Apparently we can have requests even if though the active list is empty,
so do the request retirement regardless of whether there's anything
on the active list.

The way it happened here is that during suspend intel_ring_idle()
notices the olr hanging around and then proceeds to get rid of it by
adding a request. However since there was nothing on the active lists
i915_gem_retire_requests() didn't clean those up, and so the idle work
never runs, and we leave the GPU "busy" during suspend resulting in a
WARN later.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

04 is the minor version. API version is ver1.
So let's follow same scheme used on published version at 01.org.

If really needed the minor version a follow-up updated will be
done. But for now we need to move fwd and unblock end users.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

We already set this limit for the GGTT.

This is a temporary patch until a full replacement of size_t variables
(inadequate in 32-bit kernel) is in place.

Regression from:
	commit a4e0bedc
	Author: Michel Thierry <michel.thierry@intel.com>
	Date:   Wed Apr 8 12:13:35 2015 +0100

		drm/i915: Use complete address space in true PPGTT

v2: Prettify code and explain why this is needed. (Chris)
v3: Don't hide the compilation warning in 32-bit. (Chris)
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With unified modeset and flip paths introduced recently when switching
to fbcon PSR was being disabled on fb_set_par path but re-enabled on
fb_pan_display one, causing missed screen updates and un unusable
console.

Regression introduced with:

commit bb546623
Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date:   Tue Apr 21 17:13:13 2015 +0300

    drm/i915: Unify modeset and flip paths of intel_crtc_set_config()

Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Without this frontbuffer flip when enabling planes PSR got compromised
and wasn't being enabled waiting forever on the flush that never
arrived.

Another solution would to create a enable_cursor function and split this
frontbuffer flip among the different plane enable and disable functions.
But if necessary this can be done in a follow up work. For now let's
just fix the regression.

It was removed by:

commit 87d4300a
Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date:   Tue Apr 21 17:12:54 2015 +0300

    drm/i915: Move intel_(pre_disable/post_enable)_primary to intel_display.c, and use it there.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This commit is the "sink CRC" version of:

commit 8c740dce
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Fri Oct 17 18:42:03 2014 -0300
    drm/i915: disable IPS while getting the pipe CRCs.

For some unknown reason, when IPS gets enabled, the sink CRC changes.
Since hsw_enable_ips() doesn't really guarantee to enable IPS (it
depends on package C-states), we can't really predict if IPS is
enabled or disabled while running our CRC tests, so let's just
completely disable IPS while sink CRCs are being used.

If we find a way to make IPS not change the pipe CRC result, we may
want to fix IPS and then revert this patch (and 8c740dce too). While
this doesn't happen, let's merge this patch, so the IGT tests relying
on sink CRCs can work properly.

This was discovered while developing a new IGT test, which will
probably be called kms_frontbuffer_tracking.

Testcase: igt/kms_frontbuffer_tracking (not on upstream IGT yet)
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
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>

It's totally broken, and since

commit d328c9d7
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Apr 10 16:22:37 2015 +0200

    drm/i915: Select starting pipe bpp irrespective or the primary plane

the kernel will try to use it even for the common rgb888 framebuffers.
Ville has patches to fix it all up properly, but unfortunately they're
stuck in review limbo. And since the 4.2 feature cutoff has passed we
need to somehow  handle this regression.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

chv_enable_pll() doesn't need to hold sb_lock for the entire duration of
the function. Drop the lock as soon as possible.

valleyview_set_cdclk() does a potential lock+unlock+lock+unlock cycle
with sb_lock. Grab the lock a few lines earlier so we can make do
with a single lock+unlock cycle always.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Rename dpio_lock to sb_lock to inform the reader that its primary
purpose is to protect the sideband mailbox rather than some DPIO
state.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The primary plane frobbing was removed from the sprite code in
 commit ecce87ea
 Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
 Date:   Tue Apr 21 17:12:50 2015 +0300

    drm/i915: Remove implicitly disabling primary plane for now

but the intel_flush_primary_plane() calls were left behind. Replace them
with straight forward POSTING_READ() of the sprite surface address
register.

The other user of intel_flush_primary_plane() is g4x_disable_trickle_feed()
where we can just inline the steps directly.

This allows intel_flush_primary_plane() to be killed off.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Expecting CHV power wells to be just an extended versions of the VLV
power wells, a bunch of commented out power wells were added in
anticipation when Punit folks would implement it all. Turns out they
never did, and instead CHV has fewer power wells than VLV. Rip out all
the #if 0'ed junk that's not needed.

v2: Rename the "pipe-a" well to "display" to match VLV
    Clarify the pipe A power well relationship to pipes B and C (Deepak)
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Not sure which LDO programming sequence delay should be used for the CHV
PHY, but the spec says that 600ns is "Used by default for initial
bringup", and the BIOS seems to use that, so let's do the same.
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

commit 53292cdb ("drm/i915: Workaround
to avoid lite restore with HEAD==TAIL") added a check for req0 != null
which is unnecessary.

The only way req0 could be null is if the list was empty, and this is
already addressed at the beginning of execlists_context_unqueue().
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In commit 1854d5ca
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 7 16:20:32 2015 +0100

    drm/i915: Deminish contribution of wait-boosting from clients

we removed an atomic timer based check for allowing waitboosting and
moved it below the mutex taken during RPS. However, that mutex can be
held for long periods of time on Vallyview/Cherryview as communication
with the PCU is slow. As clients may frequently wait for results (e.g.
such as tranform feedback) we introduced contention between the client
and the RPS worker. We can take advantage of the RPS worker, by
switching the wait boost decision to use spin locks and defer the
actual reclocking to the worker.

Fixes a regression of up to 45% on Baytrail and Baswell!

v2 (Daniel):
- Use max_freq_softlimit instead of the not-yet-merged boost
  frequency.
- Don't inject a fake irq into the boost work, instead treat
  client_boost as just another legit waker.

v3: Drop the now unused mask (Chris).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90112
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It was reported that this comment was confusing, and indeed it is.

v2: (one year later!) Add the range for the DRM_I915_* iotcl defines
    (Daniel)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit 118182e9.

It's causing too much trouble when compile-testing for non-i915 folks.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As Daniel commented on

commit b7ffe1362c5f468b853223acc9268804aa92afc8
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Apr 27 13:41:24 2015 +0100

    drm/i915: Free RPS boosts for all laggards

it is better to be explicit when sharing hardcoded values such as
throttle/boost timeouts. Make it so!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

After allocating from the slab cache, we then need to free the request
back into the slab cache upon error (and not call kfree as that leads
to eventual memory corruption).

Fixes regression from
commit efab6d8d
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 7 16:20:57 2015 +0100

    drm/i915: Use a separate slab for requests
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is a mplayer video failure reported with xv.
This is because there is a request to do both plane scaling
and colorkey. Because skl hw doesn't support plane scaling
and colorkey at the same time, request is failed which is expected
behavior.

To make xv operate, this patch allows colorkey continue to work
without using scaler. Then behavior would be similar to platforms
without plane scaler support.
Signed-off-by: NChandra Konduru <chandra.konduru@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90449
[danvet: change can_scale to bool as requested by Ville.]
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GTT caching was disabled by default on gen8 due to not working with
big pages. Some information suggests that it got fixed, but still
GTT caching has been left disabled by default. Or could be it just
meant that the default was changed to off, and hence the problem
got solved.

Enable GTT caching in the hopes of some performance increase.
Whether or not the big pages issue has been fixed is irrelevant
at this stage since we don't use big pages.

This gives me a 1-2% improvement in xonotic on my BSW. Haven't tried
BDW, but supposedly it has larger TLBs so might not benefit as much.
On HSW GTT caching is enabled by default.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GEN8_L3SQCREG1 isn't saved in the context (verified by going through
a context dump), and so we shouldn't be using the ring w/a code to
initialize it. Also Bspec explicitly talks about MMIO and writing it
with the CPU.

Additionally there's another w/a WaTempDisableDOPClkGating:bdw which
tells us to disable DOP clock gating around the GEN8_L3SQCREG1 write
to make sure everyone notices the change. So let's do that as well.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We're not using ilk_init_lp_watermarks() on BDW for some reason.
Probably due to the BDW patches and the relevant WM patches landing
roughlly at the same time. Fix it up.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Bspec says we should disable the FDI RX/TX before disabling the PCH
ports. Do so.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Follow the BSpec sequence for the CRT port as well on PCH platforms,
ie. disable the pipe before the port.

Didn't bother looking at DDI in detail yet, so leave that one be even
though the CRT is a PCH port there.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While at it also remove the redundant/unneeded w/a like done for hdmi
already.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Mention that this also removes the unneeded w/a, as suggested
by Jesse.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BSpec says we should disable all ports after the pipe on PCH
platforms. Do so. Fixes a pipe off timeout on ILK now caused by
the transcoder B workaround.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently the IBX transcoder B workarounds are not working correctly.
Well, the HDMI one seems to be working somewhat, but the DP one is
definitely busted.

After a bit of experimentation it looks like the best way to make this
work is first disable the port on transcoder B, and then re-enable it
transcoder A, and immediately disable it again.

We can also clean up the code by noting that we can't be called without
a valid crtc. And also note that port A on ILK does not need the
workaround, so let's check for that one too.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On IBX the SDVO/HDMI register write may be masked when enabling the
port, so it may need to written twice. The HDMI code does this, but
the SDVO code does not. Add the workaround to the SDVO code as well.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we're always enabling enhanced framing on CPT even if the sink
doesn't support it. Fix this up by actaully looking at what the sink
tells us.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Define a TRANS_DP_PIPE_TO_PORT() to make the CPT DP .get_hw_state()
pipe readout neater.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_dp.c is a mess with all the checks for different
platform/PCH variants and ports. Try to clean it up by recognizing
the following facts:
- IVB port A, and CPT port B/C/D are always the special cases
- VLV/CHV don't have port A
- Using the same kind of logic everywhere makes things much easier to
  parse

So let's move the IVB port A and PCH port B/C/D checks to be done first,
and let the other cases fall through, and always check for these things
using the same logic.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>