This function is only used in intel_dp.c since:

  commit 0e32b39c
  Author: Dave Airlie <airlied@redhat.com>
  Date:   Fri May 2 14:02:48 2014 +1000

      drm/i915: add DP 1.2 MST support (v0.7)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Even though we only support atomic plane updates at the moment, we still
need to add an .atomic_get_property() entrypoint for connectors before
we allow the driver to flip on the DRIVER_ATOMIC bit.  As soon as that
bit gets set, the DRM core will start adding atomic connector properties
(in addition to the plane properties we care about at the moment), so we
need to be able to handle the new way the DRM core will interact with
us.

For simplicity, we just lookup driver-specific connector properties in
the usual shadow array maintained by the core.  Once we get real atomic
modeset support for crtc's and planes, this code should be re-written to
pull the data out of crtc/connector state structures.

v2: Fix intel_dvo and intel_dsi that I missed on the first pass (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want to enable/test plane updates via the atomic interface, but as
soon as we flip DRIVER_ATOMIC on, the DRM core will take some atomic
codepaths to lookup properties during drmModeGetConnector() and some of
those codepaths unconditionally dereference connector->state
(specifically when looking up the CRTC ID property in
drm_atomic_connector_get_property()).  Create a dummy connector state
for each connector at init time to ensure the DRM core doesn't try to
dereference a NULL connector->state.  The actual connector properties
will never be updated or contain useful information, but since we're
doing this specifically for testing/debug of the plane operations (and
only when a specific kernel module option is given), that shouldn't
really matter.

Once we start creating connector states, the DRM core will want to be
able to clean them up for us.  We also need to hook up the destruction
entrypoint to the core's helper.

v2: Squash in the patch to set the state destruction hook (Ander & Bob)

v3: Only create dummy connector states when we're actually faking
    atomic support.  (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Calls have been added to invalidate/flush DRRS whenever invalidate/flush is
called as part of frontbuffer tracking.
Apart from calls as a result of GEM tracking to fb invalidate/flush, a
call has been added to invalidate fb obj from crtc_page_flip as well. This
is to track busyness through flip calls.
The call to fb_obj_invalidate (in flip) is placed before queuing flip for this
obj.

drrs_invalidate() and drrs_flush() check for drrs.dp which would be NULL if
it was setup in drrs_enable(). This covers for the condition when DRRS is
not supported.

v2: Removing the call to invalidate_drrs from page_flip.
This has not been tested on Android yet, but, in case DRRS transtions do not
work as expected, check by adding back this call in page_flip.
Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Calling enable/disable DRRS when enable/disable DDI are called.
These functions are responsible for setup of drrs data (in enable) and
reset of drrs (in disable).
has_drrs is true when downclock_mode is found and SEAMLESS_DRRS is set in
the VBT. A check has been added for has_drrs in these functions, to make
sure the functions go through only if DRRS will work on the platform with
the attached panel.

V2: [By Ram]: WARN_ON is used when intel_edp_drrs_enable() is called more than
once [Rodrigo]
Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add DRRS work function to trigger a switch to low refresh rate,
when no activity is detected on screen till 1 sec duration.

v2: [By Ram]: drrs.dp also protected with drrs.mutex and worker function
is renamed to intel_edp_drrs_downclock_work [Chris]
Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Self-explanatory code is better code.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To match the semantics of drm_crtc->state, which this will eventually
become. The allocation of the memory for config will be fixed in a
followup patch. By adding the extra _config field to intel_crtc it was
possible to generate this entire patch with the cocci script below.

@@ @@
struct intel_crtc {
...
-struct intel_crtc_state config;
+struct intel_crtc_state _config;
+struct intel_crtc_state *config;
...
}
@@ struct intel_crtc *crtc; @@
-memset(&crtc->config, 0, sizeof(crtc->config));
+memset(crtc->config, 0, sizeof(*crtc->config));
@@ @@
__intel_set_mode(...) {
<...
-to_intel_crtc(crtc)->config = *pipe_config;
+(*(to_intel_crtc(crtc)->config)) = *pipe_config;
...>
}
@@ @@
intel_crtc_init(...) {
...
WARN_ON(drm_crtc_index(&intel_crtc->base) != intel_crtc->pipe);
+intel_crtc->config = &intel_crtc->_config;
return;
...
}
@@ struct intel_crtc *crtc; @@
-&crtc->config
+crtc->config
@@ struct intel_crtc *crtc; identifier member; @@
-crtc->config.member
+crtc->config->member
@@ expression E; @@
-&(to_intel_crtc(E)->config)
+to_intel_crtc(E)->config
@@ expression E; identifier member; @@
-to_intel_crtc(E)->config.member
+to_intel_crtc(E)->config->member

v2: Clarify manual changes by splitting them into another patch. (Matt)
    Improve cocci script to generate even more of the changes. (Ander)
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: NDaniel Vetter <daniel.vetter@ffwll.ch>

And get rid of the duplicate mode structures. This patch was generated
with the following semantic patch:

@@ @@
struct intel_crtc_state {
+struct drm_crtc_state base;
+
...
-struct drm_display_mode requested_mode;
-struct drm_display_mode adjusted_mode;
...
}
@@ struct intel_crtc_state *state; @@
-state->adjusted_mode
+state->base.adjusted_mode
@@ struct intel_crtc_state *state; @@
-state->requested_mode
+state->base.mode
@@ struct intel_crtc_state state; @@
-state.adjusted_mode
+state.base.adjusted_mode
@@ struct intel_crtc_state state; @@
-state.requested_mode
+state.base.mode
@@ struct drm_crtc *crtc; @@
-to_intel_crtc(crtc)->config.adjusted_mode
+to_intel_crtc(crtc)->config.base.adjusted_mode
@@ identifier member; expression E; @@
-PIPE_CONF_CHECK_FLAGS(adjusted_mode.member, E);
+PIPE_CONF_CHECK_FLAGS(base.adjusted_mode.member, E);
@@ identifier member; @@
-PIPE_CONF_CHECK_I(adjusted_mode.member);
+PIPE_CONF_CHECK_I(base.adjusted_mode.member);
@@ identifier member; @@
-PIPE_CONF_CHECK_CLOCK_FUZZY(adjusted_mode.member);
+PIPE_CONF_CHECK_CLOCK_FUZZY(base.adjusted_mode.member);

v2: Completely generate the patch with cocci. (Ander)
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: NDaniel Vetter <daniel.vetter@ffwll.ch>

The objective is to make this structure usable with the atomic helpers,
so let's start with the rename. Patch generated with coccinelle:

@@ @@
-struct intel_crtc_config {
+struct intel_crtc_state {
...
}
@@ @@
-struct intel_crtc_config
+struct intel_crtc_state

v2: Completely generate the patch with cocci. (Ander)
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: NDaniel Vetter <daniel.vetter@ffwll.ch>

Earlier, DRRS structures were specific to eDP (used only in intel_dp).
Since DRRS can be extended to other internal display types
(if the panel supports multiple RR), modifying structures
to be part of drm_i915_private and have a provision to add display related
structs like intel_dp.
Also, aligning with frontbuffer tracking mechanism, the new structure
contains data for busy frontbuffer bits.
Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of pushing each byte via stack the specifier allows to supply the
pointer and length to dump buffers up to 64 bytes long.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Many distro's have mechanism in place to collect and automatically file
bugs for failed WARN()s.  And since i915 has a lot of hw state sanity
checks which result in WARN(), it generates quite a lot of noise which
is somewhat disconcerting to the end user.

Separate out the internal hw-is-in-the-state-I-expected checks into
I915_STATE_WARN()s and allow configuration via i915.verbose_checks module
param about whether this will generate a full blown stacktrace or just
DRM_ERROR().  The new moduleparam defaults to true, so by default there
is no change in behavior.  And even when disabled, you will still get
an error message logged.

v2: paint the macro names blue, clarify that the default behavior
    remains the same as before
Signed-off-by: NRob Clark <robdclark@gmail.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

After

commit a18c0af1
uthor: Thierry Reding <treding@nvidia.com>
Date:   Wed Dec 10 11:38:49 2014 +0100

    drm: Zero out DRM object memory upon cleanup

we will use the eDP encoder during destroying it. Fix this by calling
drm_encoder_cleanup() at a point when the encoder is not used any more.
This caused a NULL pointer dereference in pps_lock(), I can't see that
it caused any other problem.

All the other encoders seem to call drm_encoder_cleanup() at a safe
place.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've checked that TRANS_DDI_MODE, DP_TP_CTL MST bits are identical to
HSW/BDW on SKL, as well as the long vs short HPD bits. So we have a good
chance to be working as well as prevous platforms.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is the last in series of VLV/CHV PSR,
that finally enable PSR by adding it to HAS_PSR
and calling the proper enable and disable
functions on the right places.

Although it is still disabled by default.

v2: Rebase over intel_psr and merge Durgadoss's fixes.
v3: Fix typo.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This function was in use to check if PSR feature got enabled.
However on HSW and BDW we currently force psr exit by disabling
EDP_PSR_ENABLE bit at EDP_PSR_CTL(dev). So this function was actually
returning the active/inactive state that is different from the enable/disable
meaning and had the risk of false negative.

But anyway this check with DRRS was dangerous, since DRRS could try to get enabled
before PSR gets there. So let's just remove it for now.
A proper synchronization mechanism must be implemented later probably
using pipe config.

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

Before testing if the panel VDD is enabled on eDP cancel any pending
disable worker. This makes sure the worker will be triggered with a
delay from the last time edp_panel_vdd_schedule_off() is called, not
the first time. This avoids unnecessary overhead.

https://bugs.freedesktop.org/show_bug.cgi?id=86201

v2: use cancel_delayed_work() instead of cancel_delayed_work_sync()
as the pps_mutexes will provide the required serialization with
edp_panel_vdd_work() while the sync variant may deadlock. Suggested
by Ville Syrjälä <ville.syrjala@linux.intel.com>.
Made commit message a bit clearer.
Signed-off-by: NEgbert Eich <eich@suse.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we just make sure vdd is off before suspending, but we don't
cancel the vdd off work. The work wil not touch vdd if
want_panel_vdd==false so in theory this is fine.

In the past that was perfectly fine since the vdd off work didn't do
anything when want_panel_vdd==false, so even if the work would have been
run during system resume before i915 has resumed, nothing would happen.

However since pps_lock() will now grab the power domain references before
it can check want_panel_vdd, we may end up toggling the power wells on/off
already before the driver has resumed. That is not really acceptable, so
cancel the vdd off work when suspending the encoder.

The problem appeared when pps_lock() was introduced in:
 commit 773538e8
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Thu Sep 4 14:54:56 2014 +0300

    drm/i915: Reset power sequencer pipe tracking when disp2d is off
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

For whatever reasons this can happen. For real testcases the test will
notice the -EIO and fall over, but we also have some testcases that
just read all debugfs files. And that shouldn't cause dmesg spam.

So tune it down a bit so that we still have the information for
debugging. And change the errno so that real testcases can easily
differentiate.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84890Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

On SKL DPLL0 is used to derive CDCLK but can also be used to drive an
eDP port (as long as we don't want SSC). DPLL0 is special enough to not
be handled by the shared DPLL framework (drives CDCLK, not supposed to
enable the HDMI mode), So we need to compute the configuration
separately from the other DPLLs.

Note that we don't need to reprogram DPLL0 (which would mean bringing
down CDCLK) to support the various eDP 1.3 link rates as they all share
the same VCO (8100).
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No functional changes. Just cleaning and reorganizing it.

v2: Rebase it puting it to begin of psr rework. This helps to blame easily
at least latest changes.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No functional change. Just making it public for use outside intel_dp.c
Allowing split psr functions.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On VLV/CHV both pipes A and B have their own backlight control
registers. In order to correctly read out the current hardware state at
init we need to know which pipe is driving the eDP port. Pass that
information down from the eDP init code into the backlight code.

To determine the correct pipe we first look at which pipe is currently
configured in the port control register, if that look invalid we look
at which pipe's PPS is currently controlling the port, and if that
too looks invalid we just assume pipe A.
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>

As per spec, and similar to DDI.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add support for disabling the audio codec on vlv/chv/gen5-7, similar to
hsw/bdw.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On pre-ddi platforms we don't shut down the link when changing link
training parameters. Except when clock recovery fails too hard and we
restart with channel eq training. Which doesn't make a lot of sense
really, since just stopping/restarting the DP port at this point
violates the modeset sequence documented in the Bspec.

So let's tempt fate and try this.

This patch is motivated by a WARN_ON triggered by

commit bc76e320
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue May 20 22:46:50 2014 +0200

    drm/i915: Drop now misleading DDI comment from dp_link_down

References: https://bugs.freedesktop.org/show_bug.cgi?id=85670Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When we suspend we turn everything off so the pps should be idle, and we
also (or at least should) disable all power wells which will reset the
power sequencer port assignment. So when we resume all power sequencers
should be in their reset state. However it's at least theoretically
possible that the BIOS would touch the power seuqencer(s), so to be safe
we ought to read out the current port assignment like we do at driver
init time.

To do that we can simply call vlv_initial_power_sequencer_setup() from
the encoder ->reset() hook before calling intel_edp_panel_vdd_sanitize().
There's no danger or clobbering the pps delays since we now have those
stored within intel_dp and we don't change them once initialized.

This will make sure that the vdd state gets correctly tracked post-resume
in case the BIOS enabled it.

We need to shuffle things around a bit to get the locking right, and
while at it, make intel_edp_panel_vdd_sanitize() static and move it
around a bit to avoid a forward declaration.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The pps timestamp initialization was accidentally lost on vlv/chv in

 commit a4a5d2f8
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Thu Sep 4 14:54:20 2014 +0300

    drm/i915: Track which port is using which pipe's power sequencer

Restore it so that we avoid introducing random delays into the pps operations
during/after driver init time.

Cc: Imre Deak <imre.deak@intel.com>
Reported-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Introduce functions to enable/disable the audio codec, incorporating the
ELD setup within enable. The disable is initially limited to HSW,
covering exactly what was done previously.

The only functional difference is that ELD valid is no longer set if
there is no connector with ELD, which should be the right thing to do
anyway. Otherwise the sequence remains the same, with warts and all, in
preparation for applying more sanity.

v2: add kernel doc.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The power seqeuencer kick procedure requires the DPLL to be running
in order to complete successfully. In case the DPLL isn't currently
running when we need to kick the power seqeuncer enable it
temporarily. This can happen eg. during ->detect() when the pipe is
not already active.

To avoid needlessly duplicating the DPLL programming re-use the already
existing functions by passing a temporary pipe config to them instead
of having them consult the current pipe config at crtc->config.

v2: Introduce vlv_force_pll_{on,off}() (Daniel)
v3: Rebase due to drm_crtc vs. intel_crtc changes
    Fix a typo in commit msg (checkpatch)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com> (v1)
[danvet: Appease checkpatch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

eDP ports need the power seqeuncer whenever the port is active. Warn if
we accidentally steal the power sequener from an active eDP port. This
should not happen unless there's a bug somewhere else, but it's best to
scream loudly if it happens to help with debugging.

Note that this only checks for active pipes and not for enabled pipes
which are turned off with dpms. Which means we might run the risk that
the pps might get stolen and we can't reacquire one when enabling the
pipe again with dpms on. But on current platforms that's impossible
since we only support two edp ports with just two panel power
sequencers. So a more elaborate scheme which reserves the pps even
when the pipe is inactive isn't required.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
[danvet: Summarize my discussion with Ville about dpms on/off issues.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We should never enable the panel power twice. That would indicate a bug
somewhere else as we would need to enable the port twice without
disabling it in between. Also print the port name.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Print the port name in the VDD/PPS debugs messages.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In case we fumble something and end up picking an already used power
seqeuencer in vlv_power_sequencer_pipe() at least try to steal it
gracefully. In theory this should never happen though.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There's no power sequencer on pipe C on VLV/CHV so scream a bit if we
try to steal one from pipes other than A and B.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

VLV gets confused if two power sequencers have the same port selected.
It would seem the port doesn't start up properly in the is case and
vlv_wait_port_ready() will fail as will the link training. Clearing the
port select in the PP_ON_DELAYS register fixes this problem.

CHV doesn't seem to need this, but it doesn't seem to hurt either so
let's just do it for both to keep the code between the platforms as
uniform as possible.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If there's no power sequencer assigned to the port currently we can't
very well have vdd or panel power enabled either. If we would try to
check that from the pps registers we'd need to pick a power seqeuncer
and kick it. So let's skip the register read and the kick.

Note that there's still a bit an issue about correctly recovering pps
state from resume if the bios is nasty: With this check we'll always
assume that the pps is off. But that's better done in a follow-up
patch and it shouldn't be too harmful - at most we waste time enabling
the pps if it's on already.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
[danvet: Add note about resume issues Imre spotted.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When we pick a new power sequencer for the port but we're not doing a
full modeset, the power sequencer may have locked on to another port (or
no port). So kick it a bit to make sure it controls the port we want.

Again just like when we attempt to actually enable the DP port, we
must first write the port register with the approriate value except
the enable bit, and then we must enable the port to make the power
sequencer happy. In this case since we don't want the port actually
enabled we just toggle it on and immediately back off. Going forward
the power sequencer will keep working on that specific port until again
moved to another port.

v2: Refine the kick procedure
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When switching from one pipe to another, the power sequencer of the new
pipe seems to need a bit of kicking to lock into the port. Even the vdd
force bit doesn't work before the power sequencer has been sufficiently
kicked, so this must be done before any AUX transactions are attempted.

After extensive experimentation I've determined that it's sufficient
to first write the port register with the correct values except the
port must remain disabled, then we can do a second write to enable the
port, after which the power sequencer is operational and allows the port
to start up properly.

Contrary to my earlier theories we don't need to enable the port with
the idle pattern, so let's just use training pattern 1 as that's what
other platforms use here.

v2: Refine the kick procedure
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>