While reworking the modeset sequence, this got lost in

commit 25c5b266
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Jul 8 22:08:04 2012 +0200

    drm/i915: implement new set_mode code flow

I've noticed this because some Xorg versions seem to set up a new mode
with every crtc at (0,0) and then pan to the right multi-monitor
setup. And since some hacks of mine added more calls to mode_set using
the stored crtc->x/y my multi-screen setup blew up.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Yet again a case where the fb helper is too intimate with the crtc
helper and calls a crtc helepr function directly instead of going
through the interface vtable.

This fixes console blanking in drm/i915 with the new i915-specific
modeset code.
Reported-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As a quick reference I'll detail the motivation and design of the new code a
bit here (mostly stitched together from patchbomb announcements and commits
introducing the new concepts).

The crtc helper code has the fundamental assumption that encoders and crtcs can
be enabled/disabled in any order, as long as we take care of depencies (which
means that enabled encoders need an enabled crtc to feed them data,
essentially).

Our hw works differently. We already have tons of ugly cases where crtc code
enables encoder hw (or encoder->mode_set enables stuff that should only be
enabled in enocder->commit) to work around these issues. But on the disable
side we can't pull off similar tricks - there we actually need to rework the
modeset sequence that controls all this. And this is also the real motivation
why I've finally undertaken this rewrite: eDP on my shiny new Ivybridge
Ultrabook is broken, and it's broken due to the wrong disable sequence ...

The new code introduces a few interfaces and concepts:

- Add new encoder->enable/disable functions which are directly called from the
crtc->enable/disable function. This ensures that the encoder's can be
enabled/disabled at a very specific in the modeset sequence, controlled by our
platform specific code (instead of the crtc helper code calling them at a time
it deems convenient).

- Rework the dpms code - our code has mostly 1:1 connector:encoder mappings and
does support cloning on only a few encoders, so we can simplify things quite a
bit.

- Also only ever disable/enable the entire output pipeline. This ensures that
we obey the right sequence of enabling/disabling things, trying to be clever
here mostly just complicates the code and results in bugs. For cloneable
encoders this requires a bit of special handling to ensure that outputs can
still be disabled individually, but it simplifies the common case.

- Add infrastructure to read out the current hw state. No amount of careful
ordering will help us if we brick the hw on the initial modeset setup. Which
could happen if we just randomly disable things, oblivious to the state set up
by the bios. Hence we need to be able to read that out. As a benefit, we grow a
few generic functions useful to cross-check our modeset code with actual hw
state.

With all this in place, we can copy&paste the crtc helper code into the
drm/i915 driver and start to rework it:

- As detailed above, the new code only disables/enables an entire output pipe.
As a preparation for global mode-changes (e.g. reassigning shared resources) it
keeps track of which pipes need to be touched by a set of bitmasks.

- To ensure that we correctly disable the current display pipes, we need to
know the currently active connector/encoder/crtc linking. The old crtc helper
simply overwrote these links with the new setup, the new code stages the new
links in ->new_* pointers. Those get commited to the real linking pointers once
the old output configuration has been torn down, before the ->mode_set
callbacks are called.

- Finally the code adds tons of self-consistency checks by employing the new hw
state readout functions to cross-check the actual hw state with what the
datastructure think it should be. These checks are done both after every
modeset and after the hw state has been read out and sanitized at boot/resume
time. All these checks greatly helped in tracking down regressions and bugs in
the new code.

With this new basis, a lot of cleanups and improvements to the code are now
possible (besides the DP fixes that ultimately made me write this), but not yet
done:

- I think we should create struct intel_mode and use it as the adjusted mode
everywhere to store little pieces like needs_tvclock, pipe dithering values or
dp link parameters. That would still be a layering violation, but at least we
wouldn't need to recompute these kinds of things in intel_display.c. Especially
the port bpc computation needed for selecting the pipe bpc and dithering
settings in intel_display.c is rather gross.

- In a related rework we could implement ->mode_valid in terms of ->mode_fixup
in a generic way - I've hunted down too many bugs where ->mode_valid did the
right thing, but ->mode_fixup didn't. Or vice versa, resulting in funny bugs
for user-supplied modes.

- Ditch the idea to rework the hdp handling in the common crtc helper code and
just move things to i915.ko. Which would rid us of the ->detect crtc helper
dependencies.

- LVDS wire pair and pll enabling is all done in the crtc->mode_set function
currently. We should be able to move this to the crtc_enable callbacks (or in
the case of the LVDS wire pair enabling, into some encoder callback).

Last, but not least, this new code should also help in enabling a few neat
features: The hw state readout code prepares (but there are still big pieces
missing) for fastboot, i.e. avoiding the inital modeset at boot-up and just
taking over the configuration left behind by the bios. We also should be able
to extend the configuration checks in the beginning of the modeset sequence and
make better decisions about shared resources (which is the entire point behind
the atomic/global modeset ioctl).
Tested-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: NBen Widawsky <ben@bwidawsk.net>
Tested-by: NDamien Lespiau <damien.lespiau@intel.com>
Tested-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NVijay Purushothaman <vijay.a.purushothaman@intel.com>
Acked-by: NVijay Purushothaman <vijay.a.purushothaman@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Acked-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we have solid modeset state tracking and checking code in
place, we can do the Full Monty also after dpms calls.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... let's see whether this catches anything earlier and I can track
down a few bugs.

v2: Add more checks and also add DRM_DEBUG_KMS output so that it's
clear which connector/encoder/crtc is being checked atm. Which proved
rather useful for debugging ...

v3: Add a WARN in the common encoder dpms function, now that also
modeset changes properly update the dpms state ...

v4: Properly add a short explanation for each WARN, to avoid the need
to correlate dmesg lines with source lines accurately. Suggested by
Chris Wilson.

v5: Also dump (expected, found) for state checks (or wherever it's not
apparent from the test what exactly mismatches with expectations).
Again suggested by Chris Wilson.

v6: Due to an issue reported by Paulo Zanoni I've noticed that the
encoder checking is by far not as strict as it could and should be.
Improve this.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since this only calls crtc helper functions, of which a shocking
amount are NULL.

Now the curious thing is how the new modeset code worked with this
function call still present:

Thanks to the hw state readout and the suspend fixes to properly
quiescent the register state, nothing is actually enabled at resume
(if the bios doesn't set up anything). Which means resume_force_mode
doesn't actually do anything and hence nothing blows up at resume
time.

The other reason things do work is that the fbcon layer has it's own
resume notifier callback, which restores the mode. And thanks to the
force vt switch at suspend/resume, that then forces X to restore it's
own mode.

Hence everything still worked (as long as the bios doesn't enable
anything). And we can just kill the call to resume_force_mode.

The upside of both this patch and the preceeding patch to quiescent
the modeset state is that our resume path is much simpler:
- We now longer restore bogus register values (which most often would
  enable the backlight a bit and a few ports), causing flickering.
- We now longer call resume_force_mode to restore a mode that the
  fbcon layer would overwrite right away anyway.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need this to avoid confusing the hw state readout code with the cpt
pch plls at resume time: We'd read the new pipe state (which is
disabled), but still believe that we have a life pll connected to that
pipe (from before the suspend). Hence properly disable pipes to clear
out all the residual state.

This has the neat side-effect that we don't enable ports prematurely
by restoring bogus state from the saved register values.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With this change we can (finally!) rip out a few of the temporary hacks
and clean up a few other things:
- Kill intel_crtc_prepare_encoders, now unused.
- Kill the hacks in the crtc_disable/enable functions to always call the
  encoder callbacks, we now always call the crtc functions with the right
  encoder -> crtc links.
- Also push down the crtc->enable, encoder and connector dpms state
  updates. Unfortunately we can't add a WARN in the crtc_disable
  callbacks to ensure that the crtc is always still enabled when
  disabling an output pipe - the crtc sanitizer of the hw readout path
  can hit this when it needs to disable an active pipe without any
  enabled outputs.
- Only call crtc->disable if the pipe is already enabled - again avoids
  running afoul of the new WARN.

v2: Copy&paste our own version of crtc_in_use, too.

v3: We need to update the dpms an encoder->connectors_active states,
too.

v4: I've forgotten to kill the unconditional encoder->disable calls in
the crtc_disable functions.

v5: Rip out leftover debug printk.

v6: Properly clear intel_encoder->connectors_active. This wasn't
properly cleared when disabling an encoder because it was no longer on
the new connector list, but the crtc was still enabled (i.e. switching
the encoder of an active crtc). Reported by Jani Nikula.

v7: Don't clobber the encoder->connectors_active state of untouched
encoders. Since X likes to first disable all outputs with dpms off
before setting a new framebuffer, this hit a few warnings. Reported by
Paulo Zanoni.

v8: Kill the now stale comment warning that intel_crtc->active is not
always updated at the right times.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that set_mode also disables crtcs and expects it's new
configuration in the staged output links we need to adjust the load
detect code a bit.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This seems to be the symptom of a few neat bugs, hence be more
obnoxious when this fails.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because that's what it is. Unfortunately we can't rip this out because
the fb helper has an incetious relationship with the crtc helper - it
likes to call disable_unused_functions, among other things.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This requires a few changes
- We still need a noop function for crtc->disable, becuase the fb
  helper is a bit too intimate with the crtc helper.
- We need to clear crtc->fb ourselves in intel_crtc_disable now that
  we no longer rely on the helper's disable_unused_functions to do
  that.
- We need to split out the sare update code, becuase the crtc code
  can't call update_dpms any more, it needs to disable the crtc
  unconditionally. This is because we now keep onto the encoder ->
  crtc mapping of the (still) active output pipe configuration.
- To check that we really disable a crtc that still has encoders,
  insert a WARN_ON(!enabled) in the crtc disable function.
- Lastly, we need to walk over all crtcs to update their enabled state
  after having called commit_output_state - for all disabled crtcs the
  crtc helper code has done that for us previously.

v2: Update connector dpms and encoder->connectors_active after
disabling the crtc, too.

v3: Noop-out intel_encoder_disable. Similarly to the crtc disable
callback used by the crtc helper code we can't simply remove all these
encoder callbacks: The fb helper (which we still use) has a rather
incetious relationship with the crtc helper code ...
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... using the pipe masks from the previous patch.

Well, not quite:
- We still need to call the disable_unused_functions helper, until
  we've moved the call to commit_output_state further down and
  adjusted intel_crtc_disable a bit. The next patch will do that.
- Because we don't support (yet) mode changes on more than one crtc at
  a time, some of the modeset_pipes checks are a bit hackish - but
  that only needs fixing once we incorporate global modeset support.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is definetely a bit more generic than currently required, but if
we keep track of all crtcs that need to be disabled/enable (because
they loose an encoder or something similar), crtcs that get completely
disabled and those that we need to do an actual mode change nicely
prepares us for global modeset operations on multiple crtcs.

The only big thing missing here would be a global resource allocation
step (for e.g. pch plls), which would equally frob these bitmasks if
e.g. a crtc only needs a new pll. Or if we need to enable dithering on
an another pipe due to bandwidth constrains somewhere.

These masks aren't yet put to use in this patch, this will follow in the
next one.

v2-v5: Fix up the computations for good (hopefully).

v6: Fixup a confusion reported by Damien Lespiau: I've conserved the
(imo braindead) behaviour of the crtc helper to disable _any_
disconnected outputs if we do a modeset, even when that newly disabled
connector isn't connected to the crtc being changed by the modeset.

The effect of that is that we could disable an arbitrary number of
unrelated crtcs, which I haven't taken into account when writing this
code. Fix this up.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- Use the check_cloned helper from the previous patch.
- Use encoder->new_crtc to check crtc properties.

v2: Kill the double negation with s/!non_cloned/is_cloned, suggested
by Jesse Barnes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The "is this encoder cloned" check will be reused by the lvds encoder,
hence exract it.

v2: Be a bit more careful about that we need to check the new, staged
ouput configuration in the check_non_cloned helper ...

v3: Kill the double negation with s/!non_cloned/is_cloned/, suggested
by Jesse Barnes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While at it, adjust a few things:
- Only assigng the new mode to crtc->mode right before calling the
  mode_set callbacks - none of the previous callbacks depend upon
  this, they all use the mode argument (as they should).
- Check encoder->new_crtc instead of the current crtc to check whether
  the encoder will be used. This prepares for moving the staged output
  committing further down in the sequence. Follow-on patches will fix
  up individual ->mode_fixup callbacks (only tv and lvds are affected
  though).
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's rather pointless to compute crtc->enabled twice right away ;-)

The only thing we really have to be careful about is that we frob the
dpms state only after a successful modeset and when we've actually
haven't just disabled the crtc.

Hooray for convoluted interfaces ...
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Originally this has been introduced in

commit 6eebd6bb
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Nov 28 21:10:05 2011 +0000

    drm: Fix lack of CRTC disable for drm_crtc_helper_set_config(.fb=NULL)

With the improvements of the output state staging and no longer
overwriting crtc->fb before the hw state is updated we can now handle
crtc disabling as part of the normal modeset sequence.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Passing in the old fb, having overwritten the current fb, leads to
some neatly convoluted code. It's much simpler if we defer the
crtc->fb update to the place that updates the hw, in pipe_set_base.
This way we also don't need to restore anything in case something
fails - we only update crtc->fb once things have succeeded.

The real reason for this change is that now we keep the old fb
assigned to crtc->fb, which allows us to finally move the crtc disable
case into the common low-level set_mode function in the next patch.

Also don't clobber crtc->x and crtc->y, we neatly pass these down the
callchain already. Unfortunately we can't do the same with crtc->mode,
because that one is being used in the mode_set callbacks.

v2: Don't restore the drm_crtc object any more on failed modesets,
since we've lose an fb reference otherwise. Also (and this is the
reason this has been found), this totally confused the modeset state
tracking, since it clobbers crtc->enabled. Issue reported by Paulo
Zanoni.

v3: Rip out the entire crtc saving into struct intel_set_config, not
just the restoring part.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is the core of the new modeset logic.

The current code which is based upon the crtc helper code first
updates all the link of the new display pipeline and then calls the
lower-level set_mode function to execute the required callbacks to get
there. The issue with this approach is that for disabling we need to
know the _current_ display pipe state, not the new one.

Hence we need to stage the new state of the display pipe and only
update it once we have disabled the current configuration and before we
start to update the hw registers with the new configuration.

This patch here just prepares the ground by switching the new output
state computation to these staging pointers. To make it clearer,
rename the old update_output_state function to stage_output_state.

A few peculiarities:
- We're also calling the set_mode function at various places to update
  properties. Hence after a successfule modeset we need to stage the
  current configuration (for otherwise we might fall back again). This
  happens automatically because as part of the (successful) modeset we
  need to copy the staged state to the real one. But for the hw
  readout code we need to make sure that this happens, too.
- Teach the new staged output state computation code the required
  smarts to handle the disabling of outputs. The current code handles
  this in a special case, but to better handle global modeset changes
  covering more than one crtc, we want to do this all in the same
  low-level modeset code.
- The actual modeset code is still a bit ugly and wants to know the new
  crtc->enabled state a bit early. Follow-on patches will clean that
  up, for now we have to apply the staged output configuration early,
  outside of the set_mode functions.
- Improve/add comments in stage_output_state.

Essentially all that is left to do now is move the disabling code into
set_mode and then move the staged state update code also into
set_mode, at the right place between disabling things and calling the
mode_set callbacks for the new configuration.

v2: Disabling a crtc works by passing in a NULL mode or fb, userspace
doesn't hand in the list of connectors. We therefore need to detect
this case manually and tear down all the output links.

v3: Properly update the output staging pointers after having read out
the hw state.

v4: Simplify the code, add more DRM_DEBUG_KMS output and check a few
assumptions with WARN_ON. Essentially all things that I've noticed
while debugging issues in other places of the code.

v4: Correctly disable the old set of connectors when enabling an
already enabled crtc on a new set of crtc. Reported by Paulo Zanoni.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We actually only touch the connector -> encoder and encoder -> crtc
linking. So it's enough to just save/restore that.

While at it, also switch to kcalloc to allocate these arrays (omission
in the commit message spotted by Jesse Barnes).
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because they all are, the ioctl command never calls us with any of
these violated. Also drop a equally pointless empty debug message (and
also in set_cursor, while we're at it).

With all these changes, intel_crtc_set_config is neatly condensed down
to it's essence, the actual modeset code (or fb update calling code)

v2: The fb helper code is actually stretching ->set_config semantics a bit,
it calls it with set->mode == NULL but set->fb != NULL.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise we'll set_fb complains pretty loudly if we the crtc is off
and userspace moves the NULL fb around a bit. Yeah, this actually
happens in the wild ...
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Yikes!

But yeah, we have to do this until someone volunteers to clean up the
fb helper and rid it of its incetious relationship with the crtc
helper code.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Note that this function already clobbers the mode config state,
so we have to clean things up if something fails.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This computes what exactly changed in the modeset configuration, i.e.
whether a full modeset is required or only an update of the
framebuffer base address or no change at all.

In the future we might add more checks for e.g. when only the output
mode changed, so that we could do a minimal modeset for outputs that
support this. Like the lvds/eDP panels where we only need to update
the panel fitter.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At the end this won't be of much use to us, but meanwhile just extract
it to get a better overview of what exactly set_config does.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_crtc_set_config is an unwidly beast and is in serious need of
some function extraction. To facilitate that, introduce a struct to
keep track of all the state involved. Atm it doesn't do much more than
keep track of all the allocated memory.

v2: Apply some bikeshed to intel_set_config_free, as suggested by
Jesse Barnes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Many BIOSen forget to turn on the pipe A after resume (because they
actually don't turn on anything), so we have to do that ourselves when
sanitizing the hw state.

I've discovered this due to the recent addition of a pipe WARN that
takes the force quirk into account.

v2: Actually try to enable the pipe with a proper configuration instead
of simpyl switching it on with whatever random state the bios left it
in after resume.

v3: Fixup rebase conflict - the load_detect functions have lost their
encoder argument.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We now track the connector state in encoder->connectors_active, and
because the DP output can't be cloned, that is sufficient to track the
link state. Hence use this instead of adding yet another modeset state
variable with dubious semantics at driver load and resume time.

Also, connectors_active should only ever be set when the encoder is
linked to a crtc, hence convert that crtc test into a WARN.

v2: Rebase on top of struct intel_dp moving.

v3: The rebase accidentally killed the newly-introduced intel_dp->port
Noticed by Paulo Zanoni.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Afaict this has been used for two things:
- To prevent the crtc enable code from being run twice. We have now
  intel_crtc->active to track this in a more precise way.
- To ensure the code copes correctly with the unknown hw state after
  boot and resume. Thanks to the hw state readout and sanitize code we
  have now a better way to handle this.

The only thing it still does is complicate our modeset state space.

Having outlived its usefullness, let it just die.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Atm we can only check the connector state after a dpms call - while
doing modeset with the copy&pasted crtc helper code things are too
ill-defined for proper checking. But the idea is very much to call
this check from the modeset code, too.

v2: Fix dpms check and don't presume that if the hw isn't on that it
must not be linked up with an encoder (it could simply be switched off
with the dpms state).
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... instead of resetting a few things and hoping that this will work
out.

To properly disable the output pipelines at the initial modeset after
resume or boot up we need to have an accurate picture of which outputs
are enabled and connected to which crtcs. Otherwise we risk disabling
things at the wrong time, which can lead to hangs (or at least royally
confused panels), both requiring a walk to the reset button to fix.

Hence read out the hw state with the freshly introduce get_hw_state
functions and then sanitize it afterwards.

For a full modeset readout (which would allow us to avoid the initial
modeset at boot up) a few things are still missing:
- Reading out the mode from the pipe, especially the dotclock
  computation is quite some fun.
- Reading out the parameters for the stolen memory framebuffer and
  wrapping it up.
- Reading out the pch pll connections - luckily the disable code
  simply bails out if the crtc doesn't have a pch pll attached (even
  for configurations that would need one).

This patch here turned up tons of smelly stuff around resume: We
restore tons of register in seemingly random way (well, not quite, but
we're not too careful either), which leaves the hw in a rather
ill-defined state: E.g. the port registers are sometimes
unconditionally restore (lvds, crt), leaving us with an active
encoder/connector but no active pipe connected to it. Luckily the hw
state sanitizer detects this madness and fixes things up a bit.

v2: When checking whether an encoder with active connectors has a crtc
wire up to it, check for both the crtc _and_ it's active state.

v3:
- Extract intel_sanitize_encoder.
- Manually disable active encoders without an active pipe.

v4: Correclty fix up the pipe<->plane mapping on machines where we
switch pipes/planes. Noticed by Chris Wilson, who also provided the
fixup.

v5: Spelling fix in a comment, noticed by Paulo Zanoni
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Similar to the sdvo code we poke the dvo encoder whether the output is
active. Safe that dvo encoders are not standardized, so this requires
a new callback into the dvo chip driver.

Hence implement that for all 6 dvo drivers.

v2: With the newly added ns2501 we now have 6 dvo drivers instead of
just 5 ...
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

SDVO is the first real special case - we support multiple outputs on
the same encoder and the encoder dpms state isn't the same as when
just disabling the outputs when the encoder is cloned.

Hence we need a real connector get_hw_state function which inquires
the sdvo encoder about its active outputs.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Note that even though this connector is cloneable we still can use the
exact same test to check whether the connector is on or whether the
encoder is enabled - both the dpms code and the encoder disable/enable
frob the exact same hw state.

For dvo/sdvo outputs, this will be different.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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

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

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