It leads to a big mess when stuff interleaves. Especially with the new
patch I've submitted for the drm core to no longer artificially split
up debug messages.

v2: The size parameter to snprintf includes the terminating 0, but the
return value does not. Adjust the logic accordingly. Spotted by Mika.

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For some reason, every single time I try to run module_reload
something tries to read the connector sysfs files. This happens
after we destroy the encoders and before we destroy the connectors, so
when the sysfs read triggers the connector detect() function,
intel_conector->encoder points to memory that was already freed.

The bad backtrace is just:
    [<ffffffff8163ca9a>] dump_stack+0x54/0x74
    [<ffffffffa00c2c8e>] intel_dp_detect+0x1e/0x4b0 [i915]
    [<ffffffffa001913d>] status_show+0x3d/0x80 [drm]
    [<ffffffff813d5340>] dev_attr_show+0x20/0x60
    [<ffffffff81221f50>] ? sysfs_read_file+0x80/0x1b0
    [<ffffffff81221f79>] sysfs_read_file+0xa9/0x1b0
    [<ffffffff811aaf1e>] vfs_read+0x9e/0x170
    [<ffffffff811aba4c>] SyS_read+0x4c/0xa0
    [<ffffffff8164e392>] system_call_fastpath+0x16/0x1b

But if you add tons of memory checking debug options to your Kernel
you'll also see:
 - general protection fault: 0000
 - BUG kmalloc-4096 (Tainted: G      D W   ): Poison overwritten
 - INFO: Allocated in intel_ddi_init+0x65/0x270 [i915]
 - INFO: Freed in intel_dp_encoder_destroy+0x69/0xb0 [i915]
Among a bunch of other error messages.

So this commit just destroys the sysfs files before both the encoder
and connectors are freed.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

struct drm_mode_display now has a separate crtc_ version of the clock to
be used when we're talking about the timings given to the harwadre (was
far as the mode is concerned).

This commit is really the result of a git grep adjusted_mode.*clock and
replacing those by adjusted_mode.crtc_clock. No functional change.

v2: Rebased on drm-intel-queued-next
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

During SDVO initialisation it would be useful to a have a record of the
individual devices we try to enable and later probe - in particular to
be able to see which fail.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Done while reviewing all our allocations for fubar. Also a few errant
cases of lacking () for the sizeof operator - just a bit of OCD.

I've left out all the conversions that also should use kcalloc from
this patch  (it's only 2).
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that adjusted_mode.clock no longer contains the pixel_multiplier, we
can kill the get_clock() callback and instead do the clock readout
in get_pipe_config().

Also i9xx_crtc_clock_get() can now extract the frequency of the PCH
DPLL, so use it to populate port_clock accurately for PCH encoders.
For DP in port A the encoder is still responsible for filling in
port_clock. The FDI adjusted_mode.clock extraction is kept in place
for some extra sanity checking, but we no longer need to pretend it's
also the port_clock.

In the encoder get_config() functions fill out adjusted_mode.clock
based on port_clock and other details such as the DP M/N values,
HDMI 12bpc and SDVO pixel_multiplier. For PCH encoders we will then
do an extra sanity check to make sure the dotclock we derived from
the FDI configuratiuon matches the one we derive from port_clock.

DVO doesn't exist on PCH platforms, so it doesn't need to anything
but assign adjusted_mode.clock=port_clock. And DDI is HSW only, so
none of the changes apply there.

v2: Use hdmi_reg color format to detect 12bpc HDMI case
v3: Set adjusted_mode.clock for LVDS too
v4: Rename ironlake_crtc_clock_get to ironlake_pch_clock_get,
    eliminate the useless link_freq variable.
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>

It would be easier if adjusted_mode.clock would be the pipe pixel clock,
and it actually is, except for the cases where pixel_multiplier > 1.

So let's change intel_sdvo to use port_clock as the multiplied clock,
and then we can leave adjusted_mode.clock as pipe pixel clock.

v2: Improve port_clock documentation
    Rebased on top of SDVO pixel_multiplier fixes
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>

We've failed to properly clear out the flags when converting a dtd to
a drm mode. For more paranoia just memset the entire structure (and
drop the now redundant clears).

Also since

commit 135c81b8
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Jul 21 21:37:09 2013 +0200

    drm/i915: clean up crtc timings computation

we don't update the crtc timings any more properly, so do that again.

v2: Remove more redundant clearing, spotted by Ville.

v3: Actually make it compile. Oops.

v4: Use a temporary structure to fill in the mode and copy it over
with drm_mode_copy. This will ensure we don't clobber the mode list or
id. Suggested by Ville.

Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reported-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Use the = {}; structure clearing instead of memset as
suggested by Ville.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of just a flag bit for each of the positive/negative sync
modes drm actually uses a separate flag for each ... This upsets the
modeset checker since the adjusted mode filled out at modeset time
doesn't match the one reconstructed at check time (since the
->get_config callback already gets this right).
Reported-by: NKnut Petersen <Knut_Petersen@t-online.de>
Cc: Knut Petersen <Knut_Petersen@t-online.de>
References: http://www.gossamer-threads.com/lists/linux/kernel/1778688?do=post_view_threadedReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's totally unused, so remove the last mode_fixup appearance in i915.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The sdvo input timing needs to be the actual mode, the sdvo
encoder automatically adjusts for the need of pixel doubling or
quadrupling. This was lost in pipe config conversion of the
pixel multiplier in

commit 6cc5f341
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Mar 27 00:44:53 2013 +0100

    drm/i915: add pipe_config->pixel_multiplier

While at it ditch the intel_ prefix from the crtc in
intel_sdvo_mode_set.

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

Some Poulsbo cards seem to incorrectly report
SDVO_CMD_STATUS_TARGET_NOT_SPECIFIED instead of
SDVO_CMD_STATUS_PENDING, which causes the display to be turned off.

This could also happen to i915.
Signed-off-by: NGuillaume Clement <gclement@baobob.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's what all callers (except for the destroy callback which is called
from drm core) actually want.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Try to decypher detection failures is a little tricker at the moment as
the only indicator of progress is when output_poll_execute() tells us
the result after the connector->detect() has run. This patch adds a
telltale to the start of each detect function so that we can track
progress and associate activity more clearly with each connector.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If intel_sdvo_get_value() fails here, val is unitialized and the cross
check will compare the pipe config multiplier with a bogus value.

Instead, only set encoder_pixel_multiplier when the sdvo command has
been successful. The cross check will compare the pipe config value with
0 otherwise.

v2: Do the cross check with the initial value of encoder_pixel_multiplier (0)
if the sdvo command fails (and thus keep the warning) (Daniel Vetter)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we painstakingly track the shared pch dplls we can finally
implement pixel mutliplier readout support for pch ports, too.

v2: Undo the temporary hack to disable the sdvo pixel multiplier
cross-checking.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We don't (yet) have proper pixel multiplier readout support on pch
split platforms, so the cross check will naturally fail.

v2: Fix spelling in the comment, spotted by Ville.

v3: Since the ordering constraint is pretty tricky between the crtc
get_pipe_config callback and the encoder->get_config callback add a
few comments about it. Prompted by a discussion with Chris Wilson on
irc about why this does work anywhere else than on i915g/gm.
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In case of intel_sdvo_get_active_outputs() failing, we end up reading a
value from the stack.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's now intel_sdvo_get_capabilities().
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In

commit 53d3b4d7
Author: Egbert Eich <eich@suse.de>
Date:   Tue Jun 4 17:13:21 2013 +0200

    drm/i915/sdvo: Use &intel_sdvo->ddc instead of intel_sdvo->i2c for DDC

Egbert Eich fixed a long-standing bug where we simply used a
non-working i2c controller to read the EDID for SDVO-LVDS panels.
Unfortunately some machines seem to not be able to cope with the mode
provided in the EDID. Specifically they seem to not be able to cope
with a 4x pixel mutliplier instead of a 2x one, which seems to have
been worked around by slightly changing the panels native mode in the
VBT so that the dotclock is just barely above 50MHz.

Since it took forever to notice the breakage it's fairly safe to
assume that at least for SDVO-LVDS panels the VBT contains fairly sane
data. So just switch around the order and use VBT modes first.

v2: Also add EDID modes just in case, and spell Egbert correctly.

v3: Elaborate a bit more about what's going on on Chris' machine.

Cc: Egbert Eich <eich@suse.de>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65524
Cc: stable@vger.kernel.org
Reported-and-tested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The hotplug_mask is no longer used as the hpd interrupt setup is now
handled in the core.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

sdvo->hotplug_active is initialised during intel_sdvo_setup_outputs(),
and so we never enabled the hotplug interrupts on SDVO as we were
checking too early.

This regression has been introduced somewhere in the hpd rework for
the storm detection and handling starting with

commit 1d843f9d
Author: Egbert Eich <eich@suse.de>
Date:   Mon Feb 25 12:06:49 2013 -0500

    DRM/I915: Add enum hpd_pin to intel_encoder.

and the follow-up patches to use the new encoder->hpd_pin variable for
the different irq setup functions.

The problem is that encoder->hpd_pin was set up _before_ the output
setup was done and so before we could assess the hotplug capabilities
of the outputs on an sdvo encoder.
Reported-by: NAlex Fiestas <afiestas@kde.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=58405Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add regression note.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A broken conditional would lead to SDVOC waiting upon hotplug events on
SDVOB - and so miss all activity on its SDVO port.

This regression has been introduced in

commit 1d843f9d
Author: Egbert Eich <eich@suse.de>
Date:   Mon Feb 25 12:06:49 2013 -0500

    DRM/I915: Add enum hpd_pin to intel_encoder.

References: https://bugs.freedesktop.org/show_bug.cgi?id=58405Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add regression note.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For various reasons the hw state readout might not be able to
faithfully match the hw state:
- broken hw (like the case which motivated this patch here where the
  sdvo encoder does not implemented mandatory functionality
  correctly).
- platforms which are not supported fully with the pipe config
  infrastructure
- if our code doesn't support a given hw configuration natively, e.g.
  special restrictions on the per-pipe panel fitters when they're used
  in high-quality scaling modes.

In all these cases both fastboot and the hw state cross checker need
to be aware of these cases and act accordingly. To be able to do this
add a new quirk flag to the pipe config structure.

The specific case at hand is an sdvo encoder which doesn't implement
the get_timings function, so adjusted_mode flags will be wrong. The
strange thing though is that the encoder _does_ work, even though it
doesn't implement any of the timings functions (so neither get nor
set, neither for input nor output timings).

Not that non-compliant sdvo encoder are any surprise at all ...

v2:
- Don't read random garbage from the dtd if the get_timings call
  failed (suggested by Chris).
- Still check the interlaced flag, that's read out from someplace
  else. We want maximal paranoia, after all.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Incomplete since ilk+ support needs proper pch dpll tracking first.
SDVO get_config parts based on a patch from Jesse Barnes, but fixed up
to actually work.

v2: Make sure that we call encoder->get_config _after_ we
get_pipe_config to be consistent in both setup_hw_state and the
modeset state checker. Otherwise the clever trick with handling the
pixel mutliplier on i915G/GM where the encoder overrides the default
value of 1 from the crtc get_pipe_config function doesn't work.
Spotted by Imre Deak.

v3: Actually cross-check the pixel mutliplier (but not on pch split
platforms for now). Now actually also tested on a i915G with a sdvo
encoder plugged in.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This way we can simplify the code quite a bit.

Also add a WARN in the sdvo code to complain about a bogus value
and kill the readout code in intel_ddi.c that Jesse sneaked in.
HW state readout for the pixel multiplier will work a bit differently
in the end.

v2: Rebase on top of the fdi pixel mutliplier handling fix.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In intel_sdvo_get_lvds_modes() the wrong i2c adapter record is used
for DDC. Thus the code will always have to rely on a LVDS panel
mode supplied by VBT.
In most cases this succeeds, so this didn't get detected for quite
a while.

This regression seems to have been introduced in

commit f899fc64
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Jul 20 15:44:45 2010 -0700

    drm/i915: use GMBUS to manage i2c links
Signed-off-by: NEgbert Eich <eich@suse.de>
Cc: stable@vger.kernel.org
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add note about which commit likely introduced this issue.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In the cloned case, changing just one output but keeping the other, the
pipe state won't change and intel_crtc_update_dpms will be a nop, but we
still need to update the dpms state of the output being changed.

Only dvo, sdvo and crt are cloneable, so only those three have special
dpms functions.
Signed-off-by: NJani Nikula <jani.nikula@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>

We need to track this correctly. While at it shovel the boolean
to track whether the sdvo is in tv mode or not into pipe_config.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36997Tested-by: NPierre Assal <pierre.assal@verint.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63609Tested-by: Ncancan,feng <cancan.feng@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have a very nice infrastructure for this now!

Note that the multifunction sdvo support is pretty neatly broken: We
completely ignore userspace's request for which connector to wire up
with the encoder and just use whatever the last detect callback has
seen.

Not something I'll fix in this patch, but unfortunately something
which is also broken in the DDI code ...

v2: Don't call sdvo_tv_clock twice.
Reviewed-by: NJani Nikula <jani.nikula@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>

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>

The connector associated with the encoder is considered active when the
output associtated with this connector is active on the encoder. The
encoder itself is considered active when either there is an active
output on  it or the  respective SDVO channel is active.
Having active outputs when the SDVO channel is inactive seems to be
inconsistent: such states can be found when intel_modeset_setup_hw_state()
collects the hardware state set by the BIOS.
This inconsistency will be fixed in intel_sanitize_crtc()
(when intel_crtc_update_dpms() is called), this however only happens
when the encoder is associated with a crtc.

This patch also reverts:

     commit bd6946e8
     Author: Daniel Vetter <daniel.vetter@ffwll.ch>
     Date:   Tue Apr 2 21:30:34 2013 +0200

         drm/i915: Fix sdvo connector get_hw_state function
Signed-off-by: NEgbert Eich <eich@suse.de>
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63031
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The active output is only the currently selected one, which does not
imply that it's actually enabled. Since we don't use the sdvo encoder
side dpms support, we need to check whether the chip-side sdvo port is
enabled instead.

v2: Fix up Bugzilla links.

v3: Simplify logic a bit (Chris).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=60138
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63031
Cc: Egbert Eich <eich@pdx.freedesktop.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Egbert Eich <eich@pdx.freedesktop.org> (v2)
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- gen4 and earlier (save for g4x) only really have a 8bpc pipe, with
  the possibility to dither to 6bpc using the panel fitter
- g4x has hdmi, but no 12 bpc pipe ... !? Clamp hdmi accordingly.
- TV/SDVO out are the only connectors available on platforms with
  a pipe bpp != 8, add code to force the pipe to 8bpc unconditionally.

<rant>
The dither handling on gmch platforms is one giant disaster. I'm hoping
somewhat that vlv enabling will fix this up, but given that the 6bpc
handling for edp was simply added with another quick hack, I don't have
high hopes ...
</rant>

v2: Neither vlv nor g4x have 12bpc pipes. Still set pipe_bpp to 12*3,
but let the crtc code clamp things down to 10bpc on these platforms.

v3: Fix a bpc vs. bpp mixup in the gen4 and earlier pipe_bpp limiter
code.

v4: Drop the hunk in intel_hdmi.c about g4x/vlv 12bpc, it was wrong.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we have a useful struct for this, let's use it. Some neat
pointer-chasing required, but it's all there already.

v2: Rebased on top of the added Haswell limited color range support.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is used way too often in the enable/disable paths. And will
be even more useful in the future.

Note that correct semantics of this change highly depend upon
correct updating of intel_crtc->config: Like with all other
modeset state, we need to call ->disable with the old config,
but ->mode_set and ->enable with the new config.

v2: Do not yet use the flag in the ->disable callbacks - atm we don't
yet have support for the information stored in the pipe_config in the
hw state readout code, so this will be wrong at boot-up/resume.

v3: Rebased on top of the hdmi/dp ddi encoder merging.

v4: Fixup stupid rebase error which lead to a NULL vfunc deref.

v5: On haswell the VGA port is on the PCH!

v6: s/IS_HASWELL/HAS_DDI/, spotted by Paulo Zanoni. Also add a missing
parameter name in a function declaration.

v7: Don't forget to git add ...
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>