The wait for panel status helper will only function correctly if the
HW panel timings are programmed correctly. Returning prematurely from
this helper may lead to obscure bugs later, so sanity check the HW
timing registers.

v2:
- Check the T8, T9 fields too, we do program them (Ville)

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466096506-11937-1-git-send-email-imre.deak@intel.com

This will be needed by the next patch too so factor it out.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466084243-5388-4-git-send-email-imre.deak@intel.com

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466084243-5388-3-git-send-email-imre.deak@intel.com

The PPS registers are backed by power well #0 and as such may be reset
after system or runtime suspend (both implying a possible DC9
transition). Fix this by reusing the VLV/CHV PPS pipe-reassignment
logic. The difference on BXT is that the PPS instances are not pipe but
port (or more accurately pin) specific, so we only need to care about
the lost HW state. As opposed to VLV/CHV the SW state is fixed and
initialized during connector init.

This also paves the way towards using the actual port->PPS instance
mapping based on VBT.

This fixes eDP link training errors on BXT after suspend, where we
started the link training too early due to an incorrect T3 (panel power
on) register value.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96436Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466084243-5388-2-git-send-email-imre.deak@intel.com

Move the early PPS initialization calls next to the rest of PPS
initialization steps. This allows us to forgo a duplicated call to
intel_dp_init_panel_power_sequencer_registers() on VLV/CHV.

This will swap the order of DP AUX registration wrt. PPS initialization.
There is an existing race here in case of a user space access via the
DPAUX device node after DP AUX registration and before calling
intel_dp_init_panel_power_sequencer_registers(), but this change won't
make this worse. The fix for this is to separate DP AUX initialization
and registration, that's a separate work already underway.

The order of MST wrt. PPS init as well as the order of
intel_dp_init_panel_power_sequencer_registers() wrt.
intel_edp_panel_vdd_sanitize() also swap, which is ok, there are no
dependencies between these steps.

Suggested by Ville.

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466499109-20240-4-git-send-email-imre.deak@intel.com

The initial DPCD read for eDP detection involves using the PPS, but so
far we only initialized the PPS registers after the DPCD read. The
reason this was done so far is to preserve a possible LVDS PPS HW setup
if LVDS is detected but eDP is not. This is not an issue any more after
the previous patch, so we can move the init earlier now.

This was caught by CI with the PPS sanity checks in place and the
initial eDP DPCD readout waiting for the panel power cycle timeout
without the PPS registers being initialized.

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466499109-20240-3-git-send-email-imre.deak@intel.com

Atm on IBX/CPT we attempt to detect if eDP is present even if LVDS was
already detected and an encoder for it was registered. This involves
trying to read out the eDP DPCD, which in turn needs the same power
sequencer that LVDS uses. Poking at the VDD line at an unexpected time
may or may not interfere with the LVDS panel, but it's probably safer to
prevent this. Registering both an LVDS and an eDP connector would also
present a similar problem accessing the shared PPS at any point later in
an unexpected way.

We also need this to be able fix PPS initialization before its first use
in the next patch. For that we want to be sure that PPS is not in use
by LVDS.

v2:
- Split out the PPS init fix to a separate patch. (Chris)
- Add comment about eDP init depending on LVDS init. (Chris)
- Make the use of the intel_encoder ptr less error prone.
v3:
- Use IBX/CPT reference instead of the incorrect ILK, add a WARN about
  this. (Ville)
v4:
- Use a helper to get the lvds encoder instead of opencoding the same.
  (Ville)

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v3)
Link: http://patchwork.freedesktop.org/patch/msgid/1466499109-20240-2-git-send-email-imre.deak@intel.com

It has been found out that in some HW combination the DisplayPort
fast link training feature caused screen flickering. Let's revert
this feature for now until we can ensure that the feature works for
all platforms.

This is a manual revert of commits 5fa836a9 ("drm/i915: DP link
training optimization") and 4e96c977 ("drm/i915: eDP link training
optimization").

Fixes: 5fa836a9 ("drm/i915: DP link training optimization")
Fixes: 4e96c977 ("drm/i915: eDP link training optimization")
Cc: <stable@vger.kernel.org> # v4.2+

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91393Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NMika Kahola <mika.kahola@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466410226-19543-1-git-send-email-mika.kahola@intel.com

For all outputs except dp_mst, we have a 1:1 relationship between
connectors and encoders and the driver is relying on the atomic helpers:
we can drop the custom ->best_encoder() implementation and let the core
call drm_atomic_helper_best_encoder() for us.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-7-git-send-email-boris.brezillon@free-electrons.com

Mostly this is unexpected indents. But really it's just a
demonstration for my patch, all these issues have been found&fixed
using the correct source file and line number support I just added.
All line numbers have been perfectly accurate.

One issue looked a bit fishy in intel_lrc.c, where I don't quite grok
what sphinx is unhappy about. But since that file looks like it has
never seen a proper kernel-doc parser I figured better to fix in a
separate path.

v2: Use fancy new &drm_device->struct_mutex linking (Jani).

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The VBT has these mysterious H/V image sizes as part of the display
timings. Looking at some dumps those appear to be the physical
dimensions in mm. Which makes sense since the timing descriptor matches
the format used by EDID detailed timing descriptor, which defines these
as "H/V Addressable Video Image Size in mm".

So let's use that information from the panel fixed mode to get the
physical dimensions for LVDS/eDP/DSI displays. And with that we can
fill out the display_info so that userspace can get at it via
GetConnector.

v2: Use (hi<<8)|lo instead of broken (hi<<4)+lo
    Handle LVDS and eDP too

Cc: Stephen Just <stephenjust@gmail.com>
Tested-by: NStephen Just <stephenjust@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96255Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464685714-30507-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NMika Kahola <mika.kahola@intel.com>

If the VBT says that a certain port should be eDP (and hence fused off
from HDMI), but in reality it isn't, we need to try and acquire the HDMI
connection instead. So only trust the VBT edp setting if we can connect
to an eDP device on that port.

Fixes: d2182a66 (drm/i915: Don't register HDMI connectors for eDP ports on VLV/CHV)
References: https://bugs.freedesktop.org/show_bug.cgi?id=96288Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NPhidias Chiang <phidias.chiang@canonical.com>
Cc: Ville Syrjälä <ville.syrjala@linux.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>
Link: http://patchwork.freedesktop.org/patch/msgid/1464766070-31623-1-git-send-email-chris@chris-wilson.co.uk

Rather than let the core generate usless encoder names, let's pass in
something that actually identifies the piece of hardware we're dealing
with.

v2: Use 'DSI %c' instead of 'MIPI %c' for DSI encoders (Jani)
v3: Use port_name() in DSI code since we have it
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464371966-15190-7-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

We'll want to store the cdclk PLL (whatever PLL that is in reality) vco
frequency somewhere on other platforms too, so let's rename the
skl_vco_freq to cdclk_pll.vco, and let's store it in kHz instead of MHz
to match most of the other clocks.

v2: Drop the spurious > vs != change (Imre)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-14-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Shared plls won't get assigned until the .compute_clocks() hook gets
called, which happens from the crtc .atomic_check hook. That's too late
as the cdclk computation has already happened. So let's move the DPLL0
VCO computation into intel_dp_compute_config() so that it's done when
the cdclk computation happens. Also only do it for eDP since we only
pick DPLL0 for eDP.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

I just wanted to get rid of the rmw cycle for gen9, but this also
fixes some bugs we haven't carried over, like using recommended
precharge and timeout values.

Also I noticed that we don't set the fastwake sync length on skl, and
that's used by PSR2 selective updates. Fix that.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463590036-17824-6-git-send-email-daniel.vetter@ffwll.ch

The phy code in vlv_pre_enable_dp() and vlv_hdmi_pre_enable() is
exectly the same, so extract it to intel_dpio_phy.c.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-10-git-send-email-ander.conselvan.de.oliveira@intel.com

The code used by the DP and HDMI paths was very similar, so make them
share it. Note that this removes the write to signal level registers
from the HDMI pre pll enable path, but that's OK since those are set
in vlv_hdmi_pre_enable() function.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-9-git-send-email-ander.conselvan.de.oliveira@intel.com

The logic for setting signal levels is used for both HDMI and DP with
small variations. But it is similar enough to put behind a function
called from the encoders.

v2: Remove unrelated MST changes due to rebase fumble. (Jim Bride)
    Fix typo in the commit message. (Jim Bride)

v3: Really fix the typo. (Jim)

Cc: Jim Bride <jim.bride@linux.intel.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-8-git-send-email-ander.conselvan.de.oliveira@intel.com

The exact same code was used by HDMI and DP encoders, so move it to
intel_dpio_phy.c.

v2: Fix typo in the commit message. (Jim Bride)
v3: Call the new function chv_phy_post_pll_disable() instead of
    chv_phy_post_disable(), as it should be called after the pll
    is disabled. (Ville)

Cc: Jim Bride <jim.bride@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-7-git-send-email-ander.conselvan.de.oliveira@intel.com

The only difference between the DP and HDMI versions was the lane count.
Since lane_count is now set appropriately for HDMI too, get rid of the
duplication and move this to intel_dpio_phy.c

v2: Don't move comments about 2nd common lane staying alive. (Ville)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-6-git-send-email-ander.conselvan.de.oliveira@intel.com

The same logic is used for DP and HDMI so move it to intel_dpio_phy.c.

v2: Rebase
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-5-git-send-email-ander.conselvan.de.oliveira@intel.com

The function chv_data_lane_soft_reset() was duplicated in DP and HDMI
code. Move it to intel_dpio_phy.c.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-4-git-send-email-ander.conselvan.de.oliveira@intel.com

The code for programming voltage swing and emphasis was duplicated
between DP and HDMI code. Move that to a new file, intel_dpio_phy.c.

v2: Keep the "Use 800mV-0dB" comment in the HDMI code. (Ville)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-3-git-send-email-ander.conselvan.de.oliveira@intel.com

The driver's VDD on/off logic assumes that whenever the VDD is on we
also hold an AUX power domain reference. Since BIOS can leave the VDD on
during booting and resuming and on DDI platforms we won't take a
corresponding power reference, the above assumption won't hold on those
platforms and an eventual delayed VDD off work will do an extraneous AUX
power domain put resulting in a refcount underflow. Fix this the same
way we did this for non-DDI DP encoders:

commit 6d93c0c4 ("drm/i915: fix VDD state tracking after system
resume")

At the same time call the DP encoder suspend handler the same way as the
non-DDI DP encoders do to flush any pending VDD off work. Leaving the
work running may cause a HW access where we don't expect this (at a point
where power domains are suspended already).

While at it remove an unnecessary function call indirection.

This fixed for me AUX refcount underflow problems on BXT during
suspend/resume.

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
CC: stable@vger.kernel.org
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460963062-13211-4-git-send-email-imre.deak@intel.com
(cherry picked from commit bf93ba67)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Add new edp_dpcd variable to intel_dp.
Read and save eDP Display control capability registers to edp_dpcd.
Signed-off-by: NYetunde Adebisi <yetundex.adebisi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459865452-9138-3-git-send-email-yetundex.adebisi@intel.com

Since we've fixed up drm_dp_dpcd_read() to allow for retries when things
timeout, there's no use for having this function anymore. Good riddens.
Signed-off-by: NLyude <cpaul@redhat.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460559513-32280-5-git-send-email-cpaul@redhat.com

Since commit 30d9aa42 ("drm/i915: Read sink_count dpcd always"),
the status of a DP connector depends on its sink count value.
However, some eDP panels don't set that value appropriately,
causing them to be reported as disconnected.
Fix this by ignoring sink count for eDP.

v2: Rephrased commit message. (Ander)
    In case of eDP, returning status as connected if DPCD
    read succeeds to avoid any further operations.

Fixes: 30d9aa42 ("drm/i915: Read sink_count dpcd always")
Cc: Ander Conselvan De Oliveira <conselvan2@gmail.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reported-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Tested-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460444034-22320-1-git-send-email-shubhangi.shrivastava@intel.com

In commit 7d23e3c3 ("drm/i915: Cleaning up intel_dp_hpd_pulse") some
much needed clean-up was done, but unfortunately part of the change
broke DP MST.  The real issue was setting the connector state to
disconnected in the MST case, which is good, but the code then (after
a goto) checks if the connector state is not connected and shuts down
MST if this is the case, which is bad.  With this change both SST and
MST seem to be happy.

v2: Add removed check further up in the function to be sure that MST
    is shut down when we lose the link. (Ander)

Fixes: commit 7d23e3c3 ("drm/i915: Cleaning up intel_dp_hpd_pulse")
cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
cc: Shubhangi Shrivastava <shubhangi.shrivastava@intel.com>
cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
cc: Nathan D Ciobanu <nathan.d.ciobanu@intel.com>
Signed-off-by: NJim Bride <jim.bride@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Reviewed-by: NLyude <cpaul@redhat.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460394684-7036-1-git-send-email-jim.bride@linux.intel.com

The driver's VDD on/off logic assumes that whenever the VDD is on we
also hold an AUX power domain reference. Since BIOS can leave the VDD on
during booting and resuming and on DDI platforms we won't take a
corresponding power reference, the above assumption won't hold on those
platforms and an eventual delayed VDD off work will do an extraneous AUX
power domain put resulting in a refcount underflow. Fix this the same
way we did this for non-DDI DP encoders:

commit 6d93c0c4 ("drm/i915: fix VDD state tracking after system
resume")

At the same time call the DP encoder suspend handler the same way as the
non-DDI DP encoders do to flush any pending VDD off work. Leaving the
work running may cause a HW access where we don't expect this (at a point
where power domains are suspended already).

While at it remove an unnecessary function call indirection.

This fixed for me AUX refcount underflow problems on BXT during
suspend/resume.

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
CC: stable@vger.kernel.org
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460963062-13211-4-git-send-email-imre.deak@intel.com

We don't have a LVDS_BORDER_ENABLE type of bit for either eDP or DSI,
and just trying to frob the display timings to include borders results
in a corrupted picture. So reject the 'Center' scaling mode on GMCH
platforms for eDP and DSI.

TODO: Should really filter out the unsupported modes from the prop,
but that would be fairly invasive since the prop is now created and
stored by drm core. So leave it for a rainy day.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460488478-18311-6-git-send-email-ville.syrjala@linux.intel.comTested-by: NJani Nikula <jani.nikula@intel.com>

The underruns we were seeing when enabling eDP port A on ILK seem to
have been caused by prematurely clearing the LP1+ watermark values when
disabling LP1+ watermarks. Now that the watermarks are handled
properly, we can rip out the underrun suppression around the port A
enable.

We still need to worry about the underruns on FDI when enabling
the eDP PLL. But as Bspec tells us, we can avoid that by a vblank
wait on the pipe driving FDI just prior to enabling the eDP PLL.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459536799-18109-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>

Take a bigger hammer to the underrun suppression on ILK. Instead of
trying to suppress them at specific points in the modeset sequence just
silence them across the entire sequence. This gets rid of some underruns
at least on my ILK. Note that this changes SNB and IVB to follow the
same approach just to keep the code less convoluted. The difference is
that on those platforms we won't suppress CPU underruns for port A since
it doesn't seem to be necessary.

My ILK has port A eDP and two PCH HDMI ports, so I can't be sure this is
as effective on other PCH port types. Perhaps we still need some of
Daniel's extra vblank waits [2]?

I've still been able to trigger an underrun on the other pipe, but
fixing that perhaps needs the LP1+ disable trick I implemented here [1]
which never got merged.

A few details which hamper stress testing on my ILK are that sometimes
the PCH transcoder gets messed up and refuses to shut down, and sometimes
even the panel power sequencer apparently gets stuck on the always on
position.

[1] https://lists.freedesktop.org/archives/intel-gfx/2014-March/041317.html
[2] https://lists.freedesktop.org/archives/intel-gfx/2016-January/086397.html

v2: Add a note that we also get underruns when enabling PCH ports

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1459536799-18109-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>

This patch checks for changes in sink count between short pulse
hpds and forces full detect when there is a change.

This will allow both detection of hotplug and unplug of panels
through dongles that give only short pulse for such events.

v2: changed variable type from u8 to bool (Jani)
    return immediately if perform_full_detect is set(Siva)

v3: changed method of determining full detection from using
    pointer to return code (Siva)

v4: changed comments to indicate meaning of return value of
    intel_dp_short_pulse and explain the use of return value
    from intel_dp_get_dpcd in intel_dp_short_pulse (Ander)
Tested-by: NNathan D Ciobanu <nathan.d.ciobanu@intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459341326-13142-5-git-send-email-shubhangi.shrivastava@intel.com

Sink count can change between short pulse hpd hence this patch
adds a member variable to intel_dp so we can track any changes
between short pulse interrupts.

This patch reads sink_count dpcd always and removes its
read operation based on values in downstream port dpcd.

SINK_COUNT dpcd is not dependent on DOWNSTREAM_PORT_PRESENT dpcd.
SINK_COUNT denotes if a display is attached, while
DOWNSTREAM_PORT_PRESET indicates how many ports are available
in the dongle where display can be attached. so it is possible
for sink count to change irrespective of value in downstream
port dpcd.

Here is a table of possible values and scenarios

sink_count      downstream_port
                present
0               0               no display is attached
0               1               dongle is connected without display
1               0               display connected directly
1               1               display connected through dongle

v2: Storing value of intel_dp->sink_count that is ready
    for consumption. (Ander)
    Squashing two commits into one. (Ander)

v3: Added comment to explain the need of early return when
    sink count is 0. (Ander)
Tested-by: NNathan D Ciobanu <nathan.d.ciobanu@intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459341326-13142-4-git-send-email-shubhangi.shrivastava@intel.com

When created originally intel_dp_check_link_status()
was supposed to handle only link training for short
pulse but has grown into handler for short pulse itself.
This patch cleans up this function by splitting it into
two halves. First intel_dp_short_pulse() is called,
which will be entry point and handle all logic for
short pulse handling while intel_dp_check_link_status()
will retain its original purpose of only doing link
status related work.

intel_dp_short_pulse: All existing code other than
link status read and link training upon error status.

intel_dp_check_link_status:
The link status should be read on short pulse
irrespective of panel being enabled or not so
intel_dp_get_link_status() performs dpcd read first
then based on crtc active / enabled it will
perform the link training.

This is because short pulse is a generic interrupt
which should always be handled, because it may mean:
	1. Hotplug/unplug of MST panel
	2. Hotplug/unplug of dongle
	3. Link status change for other DP panels

v2: Added WARN_ON to intel_dp_check_link_status()
    Removed a call to intel_dp_get_link_status() (Ander)

v3: Changed commit message to explain need of link status
    being read before performing encoder checks (Daniel)

v4: Changed commit message to explain need of reading
    link status on short pulse (Ander)
Tested-by: NNathan D Ciobanu <nathan.d.ciobanu@intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
[anderco: fix parenthesis alignment]
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459341326-13142-3-git-send-email-shubhangi.shrivastava@intel.com

Current DP detection has DPCD operations split across
intel_dp_hpd_pulse and intel_dp_detect which contains
duplicates as well. Also intel_dp_detect is called
during modes enumeration as well which will result
in multiple dpcd operations. So this patch tries
to solve both these by bringing all DPCD operations
in one single function and make intel_dp_detect
use existing values instead of repeating same steps.

v2: Pulled in a hunk from last patch of the series to
    this patch. (Ander)

v3: Added MST hotplug handling. (Ander)

v4: Added a flag to check if detect is performed to
    prevent multiple detects on hotplug. (Ander)
Tested-by: NNathan D Ciobanu <nathan.d.ciobanu@intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
[anderco: fix parenthesis aligment]
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459341326-13142-2-git-send-email-shubhangi.shrivastava@intel.com

intel_dp_detect() is called for not just detection but
during modes enumeration as well. Repeating the whole
sequence during each of these calls is wasteful and
time consuming.
This patch moves probing for panel, DPCD read etc done in
intel_dp_detect() to a new function intel_dp_long_pulse().
Note that the behavior of intel_dp_detect() is changed to
report connected or disconnected depending on whether the
EDID is available or not.
This change will be required by further patches in the series
to avoid performing duplicated DPCD operations on hotplug.

v2: Moved a hunk to next patch of the series.
    Moved intel_dp_unset_edid to out. (Ander)

v3: Rephrased commit message and intel_dp_unset_dp() is called
    within intel_dp_set_dp() to free the previous EDID. (Ander)

v4: Added overriding of status to disconnected for MST. (Ander)
Tested-by: NNathan D Ciobanu <nathan.d.ciobanu@intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
[anderco: fix parenthesis alignment]
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459341326-13142-1-git-send-email-shubhangi.shrivastava@intel.com

Move all data initialized from VBT under dev_priv->vbt. No functional
changes.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458834623-8734-3-git-send-email-jani.nikula@intel.com

Housekeeping, similar to psr, backlight, and dsi. No functional changes.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458834623-8734-2-git-send-email-jani.nikula@intel.com