In case we detect a "ghost eDP", intel_edp_init_connector frees both
the connector and encoder and then returns. On Haswell, intel_ddi_init
then tries to use the freed encoder on the HDMI initialization path
since the following commit:

commit 21a8e6a4
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Apr 10 23:28:35 2013 +0200
    drm/i915: don't setup hdmi for port D edp in ddi_init

So now on intel_ddi_init we check for the "ghost eDP" case and return
without trying to initialize HDMI. This way we won't try to read the
freed "intel_encoder" struct in the next "if" statement.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NZoltan Nyul <zoltan.nyul@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because intel_dp_init_connector is too big for my poor little brain.
No functional changes.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NZoltan Nyul <zoltan.nyul@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

By the time we call intel_dp_destroy (which destroys the connector)
the encoder may have been destroyed already, so if we use it we may be
reading some free memory. That happens in drm_mode_config_cleanup()
and also inside intel_dp_init_connector() when we detect a ghost eDP.

I also hope this may solve some random memory bugs.

Reported by kmemcheck.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NZoltan Nyul <zoltan.nyul@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We always limited the link bw calculations to 24bpp. Tested with
my shiny new high-bpc screen, seems to work as advertised.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65280Tested-by: Nshui yangwei <yangweix.shui@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... not the port clock. This allows us to kill the funny semantics
around pixel_target_clock.

Since the dpll code still needs the real port clock, add a new
port_clock field to the pipe configuration. Handling the default case
for that one is a bit tricky, since encoders might not consistently
overwrite it when retrying the crtc/encoder bw arbitrage step in the
compute config stage. Hence we need to always clear port_clock and
update it again if the encoder hasn't put in something more specific.
This can't be done in one step since the encoder might want to adjust
the mode first.

I was a bit on the fence whether I should subsume the pixel multiplier
handling into the port_clock, too. But then I decided against this
since it's on an abstract level still the dotclock of the adjusted
mode, and only our hw makes it a bit special due to the separate pixel
mulitplier setting (which requires that the dpll runs at the
non-multiplied dotclock).

So after this patch the adjusted_mode accurately describes the mode we
feed into the port, after the panel fitter and pixel multiplier (or
line doubling, if we ever bother with that) have done their job.
Since the fdi link is between the pfit and the pixel multiplier steps
we need to be careful with calculating the fdi link config.

v2: Fix up ilk cpu pll handling.

v3: Introduce an fdi_dotclock variable in ironlake_fdi_compute_config
to make it clearer that we transmit the adjusted_mode without the
pixel multiplier taken into account. The old code multiplied the the
available link bw with the pixel multiplier, which results in the same
fdi configuration, but is much more confusing.

v4: Rebase on top of Imre's is_cpu_edp removal.

v5: Rebase on top of Paulo's haswell watermark fixes, which introduce
a new place which looked at the pixel_clock and so needed conversion.

v6: Split out prep patches as requested by Paulo Zanoni. Also rebase
on top of the fdi dotclock handling fix in the fdi lanes/bw
computation code.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v3)
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v6)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This prepares a bit for the next big patch, where we switch the
semantics of the different clocks in the pipe config around.

Since I've broken cpu eDP PLL handling in the first version I've
figured some refactoring is in order.

Split out on request from Paulo Zanoni.
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The patch changes all remaining is_cpu_edp() check with a check for port
A. We can do this, since in all these cases ValleyView is handled
separately and port A is always a CPU side eDP port.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On ValleyView for both eDP and DP the AUX input clock is 200MHz, so we
can calculate for both the clock divider for the 2MHz target rate at the
same place. Afterwards we can also replace the is_cpu_edp() check with a
check for port A.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Based on 3739850b - "drm/i915: disable the cpu edp port after the
cpu pipe" and the bspec disabling sequence for IVB and older it seems we
have to distinguish only the CPU vs. PCH port case, whether it's a DP or
eDP doesn't seem to matter. For IVB and older on the CPU side we can
only have eDP on port A, DP ports can only be on the PCH side. On VLV we
have only CPU side eDP/DP ports, no PCH. So the condition for the
disabling sequence we need for CPU ports is port == A || IS_VLV.

This allows us to remove is_cpu_edp() completely in a later patch.

v2:
- simplify (and fix) the condition for CPU side ports and adjust the
  commit message accordingly (Daniel)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Rename all VLV IOSF sideband register accessor functions to
vlv_<port>_{read,write}. No functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The lower level sideband read/write functions already do this.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

During DP AUX communication we might time out 1 jiffy too early, because
the calculated expiry jiffy value is one less than needed.

This is only one reason for false DP AUX timeouts. For a complete
solution we also need the following fix, which is now queued for
mainline: http://marc.info/?l=linux-kernel&m=136748515710837&w=2

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=64133Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With this, that 338 can finally become the correct 337500.

Due to the change we need to adjust the intel_dp_aux_ch function to
set the correct value, so adjust the division and also use
DIV_ROUND_CLOSEST instead of the old "round down" behavior because the
spec says the value "should be programmed to get as close as possible
to the ideal rate of 2MHz".

Quoting Paulo's follow-up to a question from Chris Wilson to explain
what exactly will change:

I use the 337500 value on the next patch, when setting the
ips_linetime value. The correct frequency is 337500, not 338000.

ips_linetime = DIV_ROUND_CLOSEST(mode->htotal * 1000 * 8,
intel_ddi_get_cdclk_freq);
For a mode with htotal of 2640 [0] we'll have: (i) (2640 * 1000 * 8) /
338000 = 62.48, resulting in 62 and (ii) (2640 * 1000 * 8) / 337500 =
62.57 resulting in 63.

For the case inside intel_dp.c:
Previously we were using 338. So with the old formula we were writing
338/2 = 169 to the register. And 337500 / 169 = 1997.04 (we use 337500
here because it's the real clock value). With the new value of
337500/2000 we'll have 168.75, which is 168 on the round-down case and
169 on the round-closest case. If we write 168 to the register, 337500
/ 168 = 2008.92, and 2008.92 is more distant from 2000 than 1997.04.
So with this patch we're changing the formula but still writing the
same correct value to the DP AUX register.

[0]: That's 1920x1080@50Hz on my DP monitor.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Pimp the commit message with Paulo's follow-up.]
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We can use this for fetching encoder specific pipe_config state, like
mode flags, adjusted clock, etc.

Just used for mode flags atm, so we can check the pipe config state at
mode set time.

v2: get_config when checking hw state too
v3: fix DVO and LVDS mode flags (Ville)
    get SDVO DTD for flag fetch (Ville)
v4: use input timings (Ville)
    correct command used (Ville)
    remove gen4 check (Ville)
v5: get DDI flag config too
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v4)
Tested-by: Paulo Zanoni <przanoni@gmail.com> (the new hsw ddi stuff)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drm_i915_private is getting bigger and bigger when adding new vbt stuff.
So, the better way of getting drm_i915_private organized is to create
a special structure for vbt stuff.

v2: Basically conflicts fixes
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There are no more users for these, so remove them.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

is_pch_edp() will be removed by the next patch, so replace it by a check
for the port and device type.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

is_pch_edp() will be removed in a follow-up patch, so replace it
with a check for the port and VBT info (for port-D eDP).

Also make things a bit clearer by using a switch on the ports.

v2:
- make the comment about not setting the conder type for DP clearer
  (Ville)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

According to BSpec the link training sequence for eDP on HSW port-A
should be as follows:

1. link training: clock recovery
2. link training: equalization
3. link training: set idle transmission mode
4. display pipe enable
5. link training: disable (set normal mode)

Contrary to this at the moment we don't do step 3. and we do step 5.
before step 4. Fix this by setting idle transmission mode for eDP at
the end of intel_dp_complete_link_train and adding a new
intel_dp_stop_link_training function to disable link training. With
these changes we'll end up with the following functions corresponding
to the above steps:

intel_dp_start_link_train    -> step 1.
intel_dp_complete_link_train -> step 2., step 3.
intel_dp_stop_link_train     -> step 5.

For port-A we'll call intel_dp_stop_link_train only after enabling the
pipe, for everything else we'll call it right after
intel_dp_complete_link_train to preserve the current behavior.

Tested on HSW/HSW-ULT.

In v2:
- Due to a HW issue we must set idle transmission mode for port-A too
  before enabling the pipe. Thanks for Arthur Runyan for explaining
  this.
- Update the patch subject to make it clear that it's an eDP fix, DP is
  not affected.

v3:
- rename intel_dp_link_train() to intel_dp_set_link_train(), use 'val'
  instead 'l' as var name. (Paulo)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit 57c21963.

It's an ugly hack for a Haswell SDV platform where the vbt doesn't
seem to fully agree with the panel. Since it seems to cause issues on
real eDP platform let's just kill this hack again.
Reported-and-tested-by: NJosh Boyer <jwboyer@gmail.com>
References: https://lkml.org/lkml/2013/5/3/467
Cc: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we ever leak a non-DP compliant port width through here, we have a
pretty serious issue. So just rip out all these WARNs - if we need
them it's probably better to have them at a central place where we
compute the dp lane count.

Also use the new DDI width macro for FDI mode.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: fixup the embarrassing s/intel_dp->DP/temp/ mistake Paulo
spotted.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Totally untested due to lack of screens supporting more than 8bpc. But
now we should have closed all holes in our bpp handling, so this
should be safe. The last missing piece was 10bpc support for g4x/vlv,
since we directly use the pipe bpp to feed the display link (and
anyway, only the cpt has any means to have a pipe bpp != the display
link bpp).
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We've had our fair share of woes already which showed that we can't
rely on the bpc limits in the EDID for eDP panels without risking
black screens. So now we limit the depth by what the BIOS recommends
in the VBT:

commit 2f4f649a
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Mon Nov 12 14:33:44 2012 +0200

    drm/i915: do not ignore eDP bpc settings from vbt

But that's not enough, since at least the panel on my ASUS Zenbook
Prime here is also unhappy if the bpc is too low. Hence just take the
firmware value and dither to get what flimsy panels want.

Like before we ensure that we don't change the bpp if the firmware
doesn't provide a value, see

commit 9a30a61f
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Mon Nov 12 14:33:45 2012 +0200

    drm/i915: do not default to 18 bpp for eDP if missing from VBT

v2: Apparently there are some horribly broken eDP panels around which
only work if the DP link is set up as if we want to driver a 24bpp
mode, but still only work if the data is feed at 18bpp. See

commit 57c21963
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Apr 4 17:19:37 2013 +0200

    drm/i915: revert eDP bpp clamping code changes

for the gory details.

Adjust the patch accordingly and update all the relevant comments.

v3: Give up on the cargo-culting v2 attempt and just enfore the edp
bpp value if it's there. Broken panels be damned!

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And put the pfit stuff into substructs while we're at it.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This gets the panel fitter working on eDP on VLV, and should also apply
to eDP panels on G4x chipsets (if we ever detect and mark an all-in-one
panel as eDP anyway).

A few cleanups are still possible on top of this, for example the LVDS
border control could be placed in the LVDS encoder structure and updated
based on the result of the panel fitter calculation.

Multi-pipe fitting isn't handled correctly either if we ever get a config
that wants to try the panel fitter on more than one output at a time.

v2: use pipe_config for storing pfit values (Daniel)
    add i9xx_pfit_enable function for use by 9xx and VLV (Daniel)
v3: fixup conflicts and lvds_dither check
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: fix up botched conflict resolution from Jesse:
- border = LVDS_BORDER_ENABLE was lost for CENTER scaling
- comment about gen2/3 panel fitter scaling was lost
- dev_priv->lvds_dither reintroduced.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the exception of hsw, which has dedicated DP clocks which run at
the fixed frequency already, and vlv, which doesn't have optmized
pre-defined dp clock parameters (yet).

v2: Ville asked me to elaborate a bit more on the longer-term goals
wrt dpll settings computation:

So ultimately my idea is that in the compute config stage first the crtc
code puts the default platform pll limits into the pipe_config. Then
encoders can either overwrite that limit structure with their own special
stuff (mostly for lvds madness). Or they can pick some or all of the
parameters (e.g. just the p2 switchover on hdmi, or all the clock
parameters for dp/sdvo tv).

Once that's done then the generic crtc code can fill out any missing bits
(using the find_best_pll code) and then try to assign which pll to use (if
it's a platform with shared plls). In the end the modeset could should
simply write the computed stuff into registers and never be able to fail.

Of course there's still a lot of data to be moved into pipe_config to make
this all happen, hence some of the temporary ugliness.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Automatic color range selection was added in

commit 55bc60db
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Thu Jan 17 16:31:29 2013 +0200

    drm/i915: Add "Automatic" mode for the "Broadcast RGB" property

but that removed the check to avoid a full modeset if the value is
unchanged. Unfortunately X sets all properties with their current
value at start-up, resulting in some ugly flickering which shouldn't
be there.

v2: Change old_range from bool to uint32_t, spotted by Ville.

v3: Actually git add everything ;-)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Minor cleanup.  Would be nice to use an enum for channel in the DPIO
macros so we don't mix up pipes and channels, but that's for another
patch.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In Valleyview voltage swing, pre-emphasis and lane control registers can
be programmed only through the h/w side band fabric.  Update
vlv_update_pll, i9xx_crtc_enable, and intel_enable_pll with the
appropriate programming.

We need to make sure that the tx lane reset occurs in both the full mode
set and DPMS paths, so factor things out to allow that.

v2: use different DPIO_DIVISOR values for VGA and DisplayPort
v3: Fix update pll logic to use same DPIO_DIVISOR & DPIO_REFSFR values
        for all display interfaces
v4: collapse with various updates
v5: squash with crtc enable/pll enable bits
v6: split out DP code (jbarnes)
    put phyready check under IS_VALLEYVIEW (jbarnes)
    remove unneeded check in 9xx pll div update (Jani)
    wrap VLV pll update call in IS_VALLEYVIEW (Jani)
    move port enable back to end of crtc enable (jbarnes)
    put phyready check under IS_VALLEYVIEW (jbarnes)
v7: fix up conflicts against latest drm-intel-next-queued
v8: use DPIO reg names, fix pipes (Jani)
    from mPhy_registers_VLV2_ww20p5 doc
v9: update to latest info from driver enabling notes doc
    driver_vbios_notes_9
v10: fixup a bit of pipe/port confusion to allow eDP and HDMI to work
     simultaneously (Jesse)
v11: use pll/port callbacks for DPIO port activity (Daniel)
     use separate VLV CRTC enable function (Daniel)
     move around port ready checks (Jesse)
Signed-off-by: NPallavi G <pallavi.g@intel.com>
Signed-off-by: NVijay Purushothaman <vijay.a.purushothaman@intel.com>
Signed-off-by: NGajanan Bhat <gajanan.bhat@intel.com>
Signed-off-by: NBen Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Drop pfit changes and add a little comment explaining that
vlv has a different enable sequence and so needs it's own crtc_enable
callback. Also apply a fixup patch from Wu Fengguang to shut up some
compiler warnings.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Program few Tx buffer Swing control settings through DPIO.

v2: fix up codingstyle (Daniel)
    call from set_signal_levels (Ville, Daniel)
    use proper port numbers (Jesse)
Signed-off-by: NPallavi G <pallavi.g@intel.com>
Signed-off-by: NYogesh M <yogesh.mohan.marimuthu@intel.com>
Signed-off-by: NGajanan Bhat <gajanan.bhat@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v2 changes)
[danvet: Reorder if-ladder to avoid two IS_VLV checks.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When an encoder is shared on several connectors there is only
one hotplug line, thus this line needs to be shared among these
connectors.
If HPD detect only works reliably on a subset of those connectors,
we want to poll the others. Thus we need to make sure that storm
detection doesn't mess up the settings for those connectors.
Therefore we store the settings in the intel_connector struct and
restore them from there.
If nothing is set but the encoder has a hpd_pin set we assume this
connector is hotplug capable.
On init/reset we make sure the polled state of the connectors
is (re)set to the default value, the HPD interrupts are marked
enabled.
Signed-off-by: NEgbert Eich <eich@suse.de>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Backlight cleanup in the eDP connector destroy callback caused the
backlight device to be removed on some systems that first initialized LVDS
and then attempted to initialize eDP. Prevent multiple backlight
initializations, and ensure backlight cleanup is only done once by moving
it to modeset cleanup.

A small wrinkle is the introduced asymmetry in backlight
setup/cleanup. This could be solved by adding refcounting, but it seems
overkill considering that there should only ever be one backlight device.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=55701Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: NPeter Verthez <peter.verthez@skynet.be>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Workaround to avoid intermittent aux channel failures, per spec change.

v2: Don't mess with cpu dp aux divider (Paulo Zanoni)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Kill spurious tab spotted by Paulo.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The behaviour around handling the eDP bpp value from vbt has been
slightly changed in

commit 36008365
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Mar 27 00:44:59 2013 +0100

    drm/i915: convert DP autodither code to new infrastructure

The old behaviour was that we used the plane's bpp (usually 24bpp) for
computing the dp link bw, but set up the pipe with the bpp value from
vbt if available. This takes the vbt bpp override into account even
for the dp link bw configuration.

On Paulo's hsw machine this resulted in a slower link clock and a
black screen - but the mode actually /should/ fit even with the lower
clock. Until we've cleared up simply stay bug-for-bug compatible with
the old code.

While at it, also restore a debug message lost in:

commit 4e53c2e0
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Mar 27 00:44:58 2013 +0100

    drm/i915: precompute pipe bpp before touching the hw

Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit deb18211.

It completely breaks the logic, since when we fall through to the end
of the function we actually _have_ figured out the correct pipe.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Jesse Barnes noticed in his review of my DP cleanup series that
intel_edp_target_clock is now unused. Checking related code I've
noticed that also intel_edp_link_config is long unused.

Kill them both.

Wrt leaky eDP functions used in the common crtc code, the only thing
still left is intel_encoder_is_pch_edp. That one is just due to the
massive confusion between eDP vs. DP and port A vs. port D. Crtc code
should at most concern itself with the later, never with the former.

But that's material for another patch series.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need it in the fdi m_n computation, which nicely kills almost
all ugly special cases in there.

It looks like we also need this to handle 12bpc hdmi correctly.

Eventually it might be better to switch things around and put the
target clock into adjusted_mode->clock and create a new pipe_config
parameter for the port link clock.

v2: Add a massive comment in the code to explain this mess.

v3: s/dp_target_clock/pixel_target_clock in anticipation of the hdmi
use-case.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>