Currently we determine the location of the AUX registers in a confusing
way. First we assume the PCH registers are used always, but then we
override it for everything but HSW/BDW to use DP+0x10. Very confusing.

Let's just make it straightforward and simply add a few functions to
pick the right AUX_CTL based on the DP port.

To deal with VLV/CHV we'll include the display_mmio_offset into the
AUX register defines.

v2: Reorder patches (Chris)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1447266856-30249-5-git-send-email-ville.syrjala@linux.intel.com

v2: Keep some MISSING_CASE() stuff (Jani)
    s/-1/-PIPE_B/ in the register macro
    Fix typo in patch subject
v3: Use PORT_B registers for invalid ports in g4x_aux_ctl_reg() (Jani)
v4: Reorder patches (Chris)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com> (v3)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Link: http://patchwork.freedesktop.org/patch/msgid/1447266856-30249-4-git-send-email-ville.syrjala@linux.intel.com

Use kasprintf() to generate the "DPDDC-<port>" name for the aux helper.

To deal with errors properly make intel_dp_aux_init() return something,
and adjust the caller to match. It seems we were also missing a
intel_dp_mst_encoder_cleanup() call on edp (non-port A) init failures,
so add that too.

The whole error/cleanup ordering doesn't feel entirely sane to me, but
I'll leave that part alone for now.

v2: Use kasprintf() instead of a table, reorder patches (Chis)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447266856-30249-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>

Instead of checking what aux_ch_ctl_reg is, we can simply check the port
when determining the right timeout value to program.

v2: Reorder patches to reduce churn (Chris)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1447266856-30249-2-git-send-email-ville.syrjala@linux.intel.com

ironlake_set_pll_cpu_edp() only gets called just before
ironlake_edp_pll_on(), so just pull the code into ironlake_edp_pll_on().

Also toss in a debug print into ironlake_edp_pll_off() to match the one
we have in ironlake_edp_pll_on().
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-15-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use intel_dp->DP in the eDP PLL setup, instead of doing RMWs.

To do this we need to move DP_AUDIO_OUTPUT_ENABLE setup to happen later,
so that we don't enable audio accidentally while configuring the PLL.

Note that actually we already enabled audio before the port due to
the double port register write magic required by VLV/CHV from
7b713f50 ("drm/i915: Fix eDP link training when switching pipes on VLV/CHV")
So that gets changed now to keep audio off as long as the port is off.

Also intel_dp_link_down() must be made to update intel_dp->DP so that we
don't re-enable the port by accident when turning off the PLL. This is
safe now that we don't call intel_dp_link_down() during link retraining.

v2: Add a note about the audio vs. port enable (Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447164977-32315-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>

Rewrite the eDP PLL state asserts to conform to our usual state assert
style.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-13-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We don't care about ILK-A and the old w/a notes may just confuse
people, so get rid of them.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-12-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The DP link frequency is 162MHz, not 160MHz. Rename the ILK eDP PLL
defines to match.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-11-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We get underruns on the other pipe when enabling the CPU eDP PLL and
port on ILK.

Bspec knows about the PLL issue, and recommends doing a vblank wait just
prior to enabling the PLL. That does seem to help, but unfortunately we
get another underrun when actually enabling the CPU eDP port. Bspec
doesn't mention that at all, and the same vblank wait trick doesn't
appear to be effective there.

Since I have no better clue how to deal with this, just hide the errors.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Doing the IBX transcoder B workaround causes underruns on
pipe/transcoder A. Just hide them by disabling underrun reporting for
pipe A around the workaround.

It might be possible to avoid the underruns by moving the workaround
to be applied only when enabling pipe A. But I was too lazy to try it
right now, and the current method has been proven to work, so didn't
want to change it too hastily.

Note that this can re-enable underrun reporting on pipe A if was
already disabled due to a previous actual underrun. But that's OK, we
may just get a second underrun report if another real underron occurrs
on pipe A.

v2: Note that pipe A underruns can get re-enabled due to this (Jani)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1446225802-11180-1-git-send-email-ville.syrjala@linux.intel.com

The function name implies it should get intel_dp, and it mostly used
where there is an intel_dp in the context.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-8-git-send-email-ander.conselvan.de.oliveira@intel.com

In order to prepare for a link training with DDI, the state machine
would call intel_ddi_prepare_link_retrain(). To remove the dependency to
the hardware information, replace that direct call with a callback.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-7-git-send-email-ander.conselvan.de.oliveira@intel.com

No functional changes, just moving code around.

v2: Rebase
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-6-git-send-email-ander.conselvan.de.oliveira@intel.com

Move register write from intel_dp_update_link_train() into
intel_dp_set_signal_levels(). This creates a better split between the
i915 specific code and the generic link training part. Note that this
causes an extra register write in intel_dp_reset_link_train(), since
both intel_dp_set_signal_levels() and intel_dp_set_link_train() write
to the DP register.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-5-git-send-email-ander.conselvan.de.oliveira@intel.com

Move the call to intel_dp_get_adjust_train() out of
intel_dp_update_link_train() and call it instead from the clock recovery
and channel equalization features. A follow up patch will remove the DP
register write from that function, so that it handles only the DPCD
write.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-4-git-send-email-ander.conselvan.de.oliveira@intel.com

Split the register write with the new link training pattern out of
intel_dp_set_link_train(), so that the i915 specific code is in a
separate function.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-3-git-send-email-ander.conselvan.de.oliveira@intel.com

It just makes the code more confusing, so just reference intel_dp_>DP
directly.

Note that this also fix a bug where the value of intel_dp->DP could be
different than the last value written to the hw, due to an early return
that would skip the 'intel_dp->DP = DP' line.

v2: Don't preserve old DP value on failure. (Sivakumar)
  - Don't call drm_dp_clock_recovery_ok() twice. (Sivakumar)
  - Keep return type of clock recovery and channel equalization
    functions as void. (Ander)

v3: Remove DP parameter from intel_dp_set_signal_levels(). (Sivakumar)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445594525-7174-2-git-send-email-ander.conselvan.de.oliveira@intel.com

BXT CRTC scaling uses the same gen9 codepaths as SKL; these codepaths
store panel fitter information in pipe_config->pch_pfit.  However since
HAS_PCH_SPLIT() is false for BXT we never actually wind up filling in
this structure (we wind up filling in pipe_config->gmch_pfit instead,
which is ignored when we go to program the hardware).  Make sure we
always take the PCH code path on gen9+ platforms.

v2: Use HAS_GMCH_DISPLAY() to more cleanly describe the platforms that
    actually want to use GMCH-style panel fitting.  (Ville)

Cc: Imre Deak <imre.deak@intel.com>
Cc: Chandra Konduru <chandra.konduru@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446656727-3516-1-git-send-email-matthew.d.roper@intel.com

Kabylake is a Intel® Processor containing Intel® HD Graphics
following Skylake.

It is Gen9p5, so it inherits everything from Skylake.

Let's start by adding the platform separated from Skylake
but reusing most of all features, functions etc. Later we
rebase the PCI-ID patch without is_skylake=1
so we don't replace what original Author did there.

Few IS_SKYLAKEs if statements are not being covered by this patch
on purpose:
   - Workarounds: Kabylake is derivated from Skylake H0 so no
     		  W/As apply here.
   - GuC: A following patch removes Kabylake support with an
     	  explanation: No firmware available yet.
   - DMC/CSR: Done in a separated patch since we need to be carefull
     	      and load the version for revision 7 since
	      Kabylake is Skylake H0.

v2: relative cleaner commit message and added the missed
    IS_KABYLAKE to intel_i2c.c as pointed out by Jani.

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Revision checks are almost always accompanied by a platform check. (The
exceptions are platform specific code.) Add helpers to check for a
platform and a revision range: IS_SKL_REVID() and IS_BXT_REVID(). In
most places this simplifies and clarifies the code. It will be obvious
that revid macros are used for the correct platform.

This should make it easier to find all the revision checks for
workarounds for each platform, and make it easier to remove them once we
drop support for early hardware revisions.

This should also make it easier to differentiate between Skylake and
Kabylake revision checks when Kabylake support is added.

v2: rebase
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445343722-3312-3-git-send-email-jani.nikula@intel.com

Prefer inclusive ranges for revision checks rather than "below B0". Per
specs A2 is not used, so revid <= A1 matches revid < B0.
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1445343722-3312-2-git-send-email-jani.nikula@intel.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

Drop some useless 'reg' variables when we only use them once.

v2: A few more, including a few variable moves
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>

Use goto to handle the error path to avoid duplicating the same code. In
the error path intel_dig_port is the last one to be released as it was
the first one to be allocated and ideally the error path should be the
reverse of the execution path.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The link training functions had confusing names. The start function
actually does the clock recovery phase of the link training, and the
complete function does the channel equalization. So call them that
instead. Also, every call to intel_dp_start_link_train() was followed
by a call to intel_dp_complete_link_train(), so add a new start
function that calls clock_recory and channel_equalization.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The docs are unclear as usual, so it's not clear whether LRC should be
bypassed, performed normally or GRC code should be used as the LRC code.
Some old docs stated that LRC bypass ought to be used, more recent ones
no longer say that. Some docs indicated that we could use GRC as the LRC
code on CHV, but the BIOS doesn't do that, so let's not do it either.

Besides to enable LRC bypass properly, I believe we should set the bit
already before deasserting cmnreset.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Previously we've relied on having basically one backlight and one
backlight type per platform. This is already a bit quirky with PMIC PWM
support on VLV/CHV platforms with MIPI DSI. In the foreseeable future
we'll have at least DPCD based backlight control on eDP and DCS command
based backlight control on MIPI DSI. Backlight is becoming more and more
connector specific, so reflect this fact by making the backlight control
hooks connector specific.

This enables further work to reuse generic backlight code in
intel_panel.c while adding more specific backlight code accessed via the
hooks.

Cc: Deepak M <m.deepak@intel.com>
Cc: Yetunde Adebisi <yetundex.adebisi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDeepak M <m.deepak@intel.com>
Reviewed-by: NYetunde Adebisi <yetundex.adebisi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make adjusted_mode const whereever we don't have to modify it. This only
covers cases when we have a local adjusted_mode variable, and doesn't
make any difference for cases where we just dereference
pipe_config->adjusted_mode.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NMika Kahola <mika.kahola@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We don't support eDP on g4x, so let's not even look at the VBT
to determine the port type, just in case the VBT is bonkers
on some g4x machines and indicates the precense of eDP.
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 Bspec is very clear that Live status must be checked about before
trying to read EDID over DDC channel. This patch makes sure that HDMI
EDID is read only when live status is up.

The live status doesn't seem to perform very consistent across various
platforms when tested with different monitors. The reason behind that is
some monitors are late to provide right voltage to set live_status up.
So, after getting the interrupt, for a small duration, live status reg
fluctuates, and then settles down showing the correct staus.

This is explained here in, in a rough way:
HPD line  ________________
			 |\ T1 = Monitor Hotplug causing IRQ
			 | \______________________________________
			 | |
                         | |
			 | |   T2 = Live status is stable
			 | |  _____________________________________
			 | | /|
Live status _____________|_|/ |
			 | |  |
			 | |  |
			 | |  |
			T0 T1  T2

(Between T1 and T2 Live status fluctuates or can be even low, depending on
 the monitor)

After several experiments, we have concluded that a max delay
of 30ms is enough to allow the live status to settle down with
most of the monitors. This total delay of 30ms has been split into
a resolution of 3 retries of 10ms each, for the better cases.

This delay is kept at 30ms, keeping in consideration that, HDCP compliance
expect the HPD handler to respond a plug out in 100ms, by disabling port.

v2: Adding checks for VLV/CHV as well. Reusing old ibx and g4x functions
to check digital port status. Adding a separate function to get bxt live
status (Daniel)
v3: Using intel_encoder->hpd_pin to check the live status (Siva)
Moving the live status read to intel_hdmi_probe and passing parameter
to read/not to read the edid. (me)
v4:
* Added live status check for all platforms using
intel_digital_port_connected.
* Rebased on top of Jani's DP cleanup series
* Some monitors take time in setting the live status. So retry for few
times if this is a connect HPD
v5: Removed extra "drm/i915" from commit message. Adding Shashank's sob
    which was missed.
v6: Drop the (!detect_edid && !live_status check) check because for DDI
ports which are enumerated as hdmi as well as DP, we don't have a
mechanism to differentiate between DP and hdmi inside the encoder's
hot_plug. This leads to call to the hdmi's hot_plug hook for DP as well
as hdmi which leads to issues during unplug because of the above check.
v7: Make intel_digital_port_connected global in this patch, some
reformatting of while loop, adding a print when live status is not
up. (Rodrigo)
v8: Rebase it on nightly which involved skipping the hot_plug hook for now
and letting the live_status check happen in detect until the hpd handling
part is finalized (Daniel)
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NSonika Jindal <sonika.jindal@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

SKL port E handling was added in

commit 26951caf
Author: Xiong Zhang <xiong.y.zhang@intel.com>
Date:   Mon Aug 17 15:55:50 2015 +0800

    drm/i915/skl: enable DDI-E hotplug

but the whole function was moved in a another branch in

commit b93433cc
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Aug 20 10:47:36 2015 +0300

    drm/i915: move ibx_digital_port_connected to intel_dp.c

and the addition was lost at some backmerge that I was unable to
identify. Put it back in.
Tested-by: NTomi Sarvela <tomix.p.sarvela@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Using intel_encoder's hpd_pin to check the live status
because of BXT A0/A1 WA for HPD pins and hpd_pin contains the
updated pin for the corresponding port.
Signed-off-by: NSonika Jindal <sonika.jindal@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When we get an i2c defer or short ack for i2c-over-aux write we need
to switch to WRITE_STATUS_UPDATE to poll for the completion of the
original request.

i915 doesn't try to interpret wht request type apart from separating
reads from writes, and so we should be able to treat this the same as
a normal i2c write.
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

TPS3 is mandatory for downstream devices that support HBR2, and Intel
platforms that support HBR2 also support TPS3. Whenever TPS3 is
supported by both the source and sink, it should be used. In other
words, whenever the source and sink are capable of 5.4 Gbps link, we
should anyway go for TPS3, regardless of the link rate being selected.

Log an error if the sink has advertized HBR2 capability without TPS3
capability.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is no need to have a separate flag for tps3 as the information is
only used at one location. Move the logic there to make it easier to
follow.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make it available outside of intel_dp.c.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NClint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we release the lane soft reset before lane stagger settings
have been programmed. I believe that means we don't actually do lane
staggering. So move the soft reset deassert to happen after lane
staggering has been programmed.

The one confusing thing in this is that when we remove the power down
override from the lanes, they power up with defaul register values,
which do not have the soft reset overrides enabled. And according to
some docs by default the data lane resets are tied to cmnreset. So that
would mean that lanes would come out of reset without staggering as
soon as the power down overrides are removed. But since we can't access
either the lane stagger register nor the soft reset override registers
until the lanes are powered on, we can't really do anything about it.
So let's just set the soft reset overrides as soon as the lane is
powered on and hope for the best.

v2: Fix typos in commit message (Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The DP MST encoder config function never sets ddi_pll_sel, even though
its value is programmed in its ->pre_enable() hook. That used to work
because a new pipe_config was kzalloc'ed at every modeset, and the value
of zero selects the highest clock for the PLL. Starting with the commit
below, the value of ddi_pll_sel is preserved through modesets, and since
the correct value wasn't properly setup by the MST code, it could lead
to warnings and blank screens.

commit 8504c74c
Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date:   Fri May 15 11:51:50 2015 +0300

    drm/i915: Preserve ddi_pll_sel when allocating new pipe_config

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91628
Cc: stable@vger.kernel.org # 7e6313a2 drm/i915: Don't use link_bw for PLL setup
Cc: stable@vger.kernel.org
Cc: Timo Aaltonen <tjaalton@ubuntu.com>
Cc: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

No functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: s/intel_dp_tps/drm_dp_tps/.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>