Both busy_ioctl and the new wait_ioct need to do the same dance (or at
least should). Some slight changes:
- busy_ioctl now unconditionally checks for olr. Before emitting a
  require flush would have prevent the olr check and hence required a
  second call to the busy ioctl to really emit the request.
- the timeout wait now also retires request. Not really required for
  abi-reasons, but makes a notch more sense imo.

I've tested this by pimping the i-g-t test some more and also checking
the polling behviour of the wait_rendering_timeout ioctl versus what
busy_ioctl returns.

v2: Too many people complained about unplug, new color is
flush_active.

v3: Kill the comment about the unplug moniker.

v4: s/un-active/inactive/
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of checking for !CPT, check for IBX to make it clearer that
this is a IBX-specific workaround. No functional change because we
smash the PPT PCH into the HAS_PCH_CPT check and atm DP isn't enabled
on the haswell LPT PCH yet.

See Bspec Vol 3, Part 3, Section 4.[3-5].1 about DP[BCD], bit 30 for
details of this workaround.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Positively checking for the required feature/gen is simpler than build
a cascade of negative "we need to bail" checks. And the later won't
scale if we add more stuff that doesn't fit in nicely.
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This fixes an (albeit really hard to hit) race resulting in an oops:
- The parity work get scheduled.
- We re-init the irq state and call INIT_WORK again.
- The workqueue code tries to run the work item and stumbles over a
  work item that should be on it's runlist.

Also initiliaze the work item unconditionally like all the others,
it's simpler.
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Notice by Fengguang Wu's automatic sparse checker.
Reported-by: NFengguang Wu <wfg@linux.intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is used to export a vmapping to the udl driver so that
i915 and udl can share the udl scanout.
Signed-off-by: NDave Airlie <airlied@redhat.com>

This just adds a stub for now, until we have some users in
place to test this functionality properly.
Signed-off-by: NDave Airlie <airlied@redhat.com>

Dumb binary interfaces which allow root-only updates of the cache
remapping registers. As mentioned in a previous patch, software using
this interface needs to know about HW limits, and other programming
considerations as the kernel interface does no checking for these things
on the root-only interface.

v1: Drop extra posting reads (Chris)
Return negative values in the sysfs interfaces on errors (Chris)

v2: Return -EINVAL for offset % 4 (Jesse)
Move schizo userspace check out (Jesse)
Cleaner sysfs item initializers (Daniel)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If any l3 rows have been previously remapped, we must remap them after
GPU reset/resume too.

v2: Just return (no warn) on remapping init if not IVB (Jesse)
Move the check of schizo userspace to i915_gem_l3_remap (Jesse)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The previous patch put all the code, and handlers in place. It should
now be safe to enable the parity error interrupt. The parity error must
be unmasked in both the GTIMR, and the CS IMR. Unfortunately, the docs
aren't clear about this; nevertheless it's the truth.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On IVB hardware we are given an interrupt whenever a L3 parity error
occurs in the L3 cache. The L3 cache is used by internal GPU clients
only.  This is a very rare occurrence (in fact to test this I need to
use specially instrumented silicon).

When a row in the L3 cache detects a parity error the HW generates an
interrupt. The interrupt is masked in GTIMR until we get a chance to
read some registers and alert userspace via a uevent. With this
information userspace can use a sysfs interface (follow-up patch) to
remap those rows.

Way above my level of understanding, but if a given row fails, it is
statistically more likely to fail again than a row which has not failed.
Therefore it is desirable for an operating system to maintain a lifelong
list of failing rows and always remap any bad rows on driver load.
Hardware limits the number of rows that are remappable per bank/subbank,
and should more than that many rows detect parity errors, software
should maintain a list of the most frequent errors, and remap those
rows.

V2: Drop WARN_ON(IS_GEN6) (Jesse)
DRM_DEBUG row/bank/subbank on errror (Jesse)
Comment updates (Jesse)
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A 30 ms delay is simply way too big to waste cpu cycles on.
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Jesse extracted this nice helper in his i9xx_crtc_mode_set refactor,
but we have the identical code in ironlake_ccrtc_mode_set. And that
function is huge, so extracting some code full of magic numbers is
always nice.

Noticed while trying to get a handle on our dp clock code.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Already discovered in

commit 5a117db7
Author: Eugeni Dodonov <eugeni.dodonov@intel.com>
Date:   Thu Jan 5 09:34:29 2012 -0200

    drm/i915: there is no pipe CxSR on ironlake

but we've failed to rip out the code from the ironlake specific code.
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On IVB and older, we basically have two registers: the control and the
data register. We write a few consecutitve times to the control
register, and we need these writes to arrive exactly in the specified
order.

Also, when we're changing the data register, we need to guarantee that
anything written to the control register already arrived (since
changing the control register can change where the data register
points to). Also, we need to make sure all the writes to the data
register happen exactly in the specified order, and we also *can't*
read the data register during this process, since reading and/or
writing it will change the place it points to.

So invoke the "better safe than sorry" rule and just be careful and
put barriers everywhere :)

On HSW we still have a control register that we write many times, but
we have many data registers.
Demanded-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

HSW support is now just like all the other generations: we send AVI
and SPD InfoFrames. There are other DIPs for HSW, but there are other
DIPs for the previous generations too. For each gen, we can see which
DIPs are missing by looking at the 'set_infoframes' function: we
explicitly disable the DIPs we're not using.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The register that controls the HDMI port can be used to control the
sDVO port. Some bits are defined only for sDVO, and SDVO_BORDER_ENABLE
is one of those: HDMI ports that can't be used in sDVO mode don't even
have this bit defined in their specifications.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At this time, the HDMI port is enabled, and the DIP control register
specification says we need to disable the port *before* disabling the
DIPs. Also, while doing this we risk telling the HW to send the AVI
DIPs once (not every VSync), which really seems to confuse the HW and
trigger bugs where the DIPs are not sent.

This code was here just to set the DIP register to a 'known state'
before using it, but since now the set_infoframes functions already
set the control registers to a known state, this code can go away.

Also, the previous code disables *all* the DIP registers for *each*
HDMI port, so we end disabling each DIP register more than once.

This patch solves a problem I can reproduce on my IVB machine. When I
boot it with just a single HDMI monitor, the AVI InfoFrames are not
sent. With this patch, the InfoFrames are sent. Previously, I wrote a
patch to 'touch the DIP registers after we enable the HDMI port' to
solve this same problem, but that patch doesn't seem to be needed
anymore after this patch.

All this patch does is revert a chunk of the following commit:

    commit 64a8fc01
    Author: Jesse Barnes <jbarnes@virtuousgeek.org>
    Date:   Thu Sep 22 11:16:00 2011 +0530

        drm/i915: fix ILK+ infoframe support

So bugs that can be bisected to that commit may be fixed now.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43256Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The register specification says we need to do this.

V2: Only write the register if the port is enabled.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

From this point on, the 'set_infoframe' functions always set the DIP
registers to a known state, so anything done will always be undone at
the modeset.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This function is called when the pipe is disabled, so it always gets
the 50ms timeout.

This function is called once for each InfoFrame, so we actually get a
100ms timeout. Will be more if we add more InfoFrames.

Also, the spec says we need to "wait for a VSync to ensure completion
of any pending DIP transmissions", not for a VBlank. OTOH, the
register documentation suggests that the DIPs are sent *during* the
VSync, so shouldn't we be waiting until *after* the VSync to ensure
all DIPs are sent?

So this wait_for_vblank seems, besides useless, totally wrong.

If we ever want to change some specific InfoFrame on-the-fly (outside
of the modeset code), the code that changes the InfoFrame will have to
do the waiting itself, and properly.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So the write_infoframe function can assume the DIP is on.

V2: Be more defensive and add WARN().
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Not once for each InfoFrame. Now we have a function that allows us to
do this.

[danvet: Paulo clarified on irc that a later bugfix patch needs this
cleanup.]
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This solves problems that happen when you alternate between HDMI and
DVI on the same port. I can reproduce these problems using DP->HDMI
and DP->DVI adapters on a DP port.

When you first plug HDMI and then plug DVI, you need to stop sending
DIPs, even if the port is in DVI mode (see the HDMI register spec). If
you don't stop sending DIPs, you'll see a pink vertical line on the
left side of the screen, some modes will give you a black screen, some
modes won't work correctly.

When you first plug DVI and then plug HDMI, you need to properly
enable the DIPs, otherwise the HW won't send them. After spending a
lot of time investigating this, I concluded that if the DIPs are
disabled, we should not write to the DIP register again because when
we do this, we also set the AVI InfoFrame frequency to "once", and
this seems to really confuse our hardware. Since this problem was not
exactly easy to debug, I'm adopting the defensive behavior and not
just avoing the "disable twice" sequence, but also explicitly
selecting the AVI InfoFrame and setting its frequency to a correct
one.

Also, move the "is_dvi" check from intel_set_infoframe to the
set_infoframes functions since now they're going to be the first ones
to deal with the DIP registers.

This patch adds the code to fix the problem, but it depends on the
removal of some code that can't be removed right now and will come
later in the patch series. The patch that we need is:
  - drm/i915: don't write 0 to DIP control at HDMI init

[danvet: Paulo clarified that this additional patch is only required
to make the fix complete, this patch here alone doesn't introduce a
regression but only partially solves the problem of randomly clearing
the dip registers.]

V2: Be even more defensive by selecting AVI and setting its frequency
outside the "is_dvi" check.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need a function that is able to fully 'set' the state of the DIP
registers to a known state.

Currently, we have the write_infoframe function that is called twice:
once for AVI and once for SPD. The problem is that write_infoframe
tries to keep the state of the DIP register as it is, changing only
the minimum necessary bits. The second problem is that
write_infoframe does twice (once for each time it is called) some
work that should be done only once (like waiting for vblank and
setting the port). If we add even more DIPs, it will do even more
repeated work.

This patch only adds the infrastructure keeping the code behavior the
same as before.

v2: add static keywords
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Paulo pointed out that gen4 re-used the SDVO registers for HDMI (the
separate HDMI registers where introduced with the first PCH) and so
g4x_hdmi_connected() never selected the right bit and always returned
disconnected.

Regression in

commit 8ec22b21
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri May 11 18:01:34 2012 +0100

    drm/i915/hdmi: Query the live connector status bit for G4x

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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Wait request is poorly named IMO. After working with these functions for
some time, I feel it's much clearer to name the functions more
appropriately.

Of course we must update the callers to use the new name as well.

This leaves room within our namespace for a *real* wait request function
at some point.

Note to maintainer: this patch is optional.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This helps implement GL_ARB_sync but stops short of allowing full blown
sync objects. Finally we can use the new timed seqno waiting function
to allow userspace to wait on a buffer object with a timeout. This
implements that interface.

The IOCTL will take as input a buffer object handle, and a timeout in
nanoseconds (flags is currently optional but will likely be used for
permutations of flush operations). Users may specify 0 nanoseconds to
instantly check.

The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any
non-zero timeout parameter the wait ioctl will wait for the given number
of nanoseconds on an object becoming unbusy. Since the wait itself does
so holding struct_mutex the object may become re-busied before this
completes. A similar but shorter race condition exists in the busy
ioctl.

v2: ETIME/ERESTARTSYS instead of changing to EBUSY, and EGAIN (Chris)
Flush the object from the gpu write domain (Chris + Daniel)
Fix leaked refcount in good case (Chris)
Naturally align ioctl struct (Chris)

v3: Drop lock after getting seqno to avoid ugly dance (Chris)

v4: check for 0 timeout after olr check to allow polling (Chris)

v5: Updated the comment. (Chris)

v6: Return -ETIME instead of -EBUSY when timeout_ns is 0 (Daniel)
Fix the commit message comment to be less ugly (Ben)
Add a warning to check the return timespec (Ben)

v7: Use DRM_AUTH for the ioctl. (Eugeni)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We still don't understand why this fails exactly, but if fails way
too often for a simple debug information. Furthermore the current
ducttape should prevent the gpu from getting stuck at low frequencies.

Hence tune down the dmesg noise.

Note that the known failure case is that the register read returns 0
when the gpu gets confused.

v2: Add comments about the known failure case.
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is now used intentionally to prevent proliferation of is-pinned
checks upon the inactive list following:

commit 1b50247a
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 24 15:47:30 2012 +0100

    drm/i915: Remove the list of pinned inactive objects

Reported-and-tested-by: guang.a.yang@intel.com
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50075Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Broadwater and Crestline share a limitation that prevent it from
relocating general surface state above 4GiB. The only recourse we have
since any buffer object may be used as a relocation target is then to
limit all object allocations on 965g[m] to DMA32.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The trace events adds whether or not the wait was blocking. Blocking in
this case means to hold struct_mutex (ie. no new work can be submitted
during the wait). The information is inherently racy.

The blocking information is racy since mutex_is_locked doesn't check
that the current thread holds the lock. The only other option would be
to pass the boolean information of whether or not the class was blocking
down through the stack which is less desirable.

v2: Don't do a trace event per loop. (Chris)
Only get blocking/non-blocking info (Chris)

v3: updated comment in code as well as commit msg (Daniel)
Add "(NB)" to trace information to remind us in 6 months (Ben)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Insert a wait parameter in the code so we can possibly timeout on a
seqno wait if need be. The code should be functionally the same as
before because all the callers will continue to retry if an arbitrary
timeout elapses.

We'd like to have nanosecond granularity, but the only way to do this is
with hrtimer, and that doesn't fit well with the needs of this code.

v2: Fix rebase error (Chris)
Return proper time even in wedged + signal case (Chris + Ben)
Use timespec constructs (Ben)
Didn't take Daniel's advice regarding the Frankenstein-ness of the
  function. I did try his advice, but in the end I liked the way the
  original code looked, better.

v3: Make wakeups far less frequent for infinite waits (Chris)

v4: Remove dummy_wait variable (Daniel)
Use raw monotonic time instead of jiffies (made the code a bit cleaner) (Ben)
Added a couple of warnings (Ben)

v5: Remove warnings (Daniel)
Use more accurate time diff for default case (Daniel)
Bikeshed for setting the return timespec in timeout case (Daniel)
s/jiffies/time in one of the comments
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Media turbo requests can either use RPVSWREQ or RPNSWREQ to indicate
what the interrupt handler should do.  Since we only deal with the
latter in our turbo code, make the media engine use that for turbo
requests.

Cc: stable@vger.kernel.org.
Tested-by: NJoe Bloggsian <joebloggsian@gmail.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

These are ultra-low-res modes used to upscale SDTV content and we
don't know how to support these on dp on intel hw:
- It's unclear whether we can send avi infoframes over dp ports.
- And the pixel repeat setting that work for hdmi/sdvo explicitly
  don't work for dp.

So don't bother and just reject these modes. These modes have been
introduced in

commit 54ac76f8
Author: Christian Schmidt <schmidt@digadd.de>
Date:   Mon Dec 19 14:53:16 2011 +0000

    drm/edid: support CEA video modes.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45729Tested-by: NYuang Guang <guang.a.yang@intel.com>
Cc: stable@vger.kernel.org
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>

These 2 modes were removed by mistake during a clean up.
So, now it is time to add them back. For further info about
supported mode and standard timing table please check:
VOL_3_display_registers_updated.pdf at intellinuxgraphics.org.

Note that this regression has been introduce in

commit 55a6713b
Author: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Date:   Thu Dec 15 14:47:33 2011 -0200

    drm/i915: Removing TV Out modes.

and this commit partially reverts it by re-adding the wrongly removed
modes.
Reported-by: NRobert Lowery <rglowery@exemail.com.au>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
[danvet: Pimped commit message to cite the commit that introduced this
regression.]
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise the hw will get confused and result in a black screen.

This regression has been most likely introduce in

commit 974b9331
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Sep 5 00:44:20 2010 +0100

    drm/i915/tv: Poll for DAC state change

That commit replace the first msleep(20) with a busy-loop, but failed
to keep the 2nd msleep around. Later on we've replaced all these
msleep(20) by proper vblanks.

For reference also see the commit in xf86-video-intel:

commit 1142be53eb8d2ee8a9b60ace5d49f0ba27332275
Author: Jesse Barnes <jbarnes@hobbes.lan>
Date:   Mon Jun 9 08:52:59 2008 -0700

    Fix TV programming:  add vblank wait after TV_CTL writes

    Fxies FDO bug #14000; we need to wait for vblank after
    writing TV_CTL or following "DPMS on" calls may not actually enable the output.

v2: As suggested by Chris Wilson, add a small comment to ensure that
no one accidentally removes this vblank wait again - there really
seems to be no sane explanation for why we need it, but it is
required.

Launchpad: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/763688Reported-and-Tested-by: NRobert Lowery <rglowery@exemail.com.au>
Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This box has DisplayPort and VGA, but no LVDS. Product specs are at
http://h10010.www1.hp.com/wwpc/us/en/sm/WF25a/12454-12454-321959-338927-3640406-4282707.html?dnr=1
and dmidecode output can be found at http://www.getslash.de/bug_attachments/dmidecode-t5740e.txtSigned-off-by: NJan-Benedict Glaw <jbglaw@getslash.de>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have one bug report from a validation team that we get the eDP
panel sequencing still somewhat wrong: We need to enable VDD while
switching off the panel and backlight. Unfortunately that reporter
seems to have fallen off the earth :(

For another reporter this actually fixes a black panel issue because
without this the backlight/panel gets confused and doesn't light up
again.

v2: I've forgotten to remove the vdd_off call in panel_off which is
now bogus. This essentially reverts

commit 17038de5
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Apr 16 22:43:42 2012 +0100

    drm/i915/dp: Flush any outstanding work to turn the VDD off

v3: the current panel_off code forces off the vdd power, too. Which is
bogus and resulted in some funny warnings later on when we've tried to
do aux channel communications with just the vdd forced on. Fix this,
too.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=46312
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43163Tested-by: NVincent Frentzel <zcecc22@gmail.com>
Cc: stable@kernel.org
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The existing assertions were written under the assumption that we wanted
to test the related PLL to a CRTC. With the split of PLL into a
separately managed entity which may be shared amongst CRTCs, we need to
pass in both the CRTC and the PLL to the assertion routine.
Occassionally, this means passing NULL for the CRTC as we wish to check
the status of the PLL irrespective of the current CRTC.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>