No need to apply WaForceL3Serialization:vlv twice.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The specs are a bit unclear whether the per-plane trickle feed disable
control exists on VLV. There is another trickle feed disable control
in the MI_ARB register.

After some experimentation it turns out both the DSPCNTR trickle feed
bits and the MI_ARB bit can be toggled. However the DSPCNTR bits don't
seem to have any effect.

The MI_ARB bit, on the other hand, has a noticable effect. I performed
an experiment where I reduced the FIFO size via DSPARB and observed the
effect of the MI_ARB trickle feed bit on the display.

Using a 1920x1080-60 mode, with MI_ARB=0x4 the display started to have
problems with DSPARB=0x42424242, whereas with MI_ARB=0x0 the problems
didn't start until DSPARB=0x09090909. This seems to confirm that the
MI_ARB trickle feed bit actually does work.

So replace the use of the DSPCNTR trickle feed bits with MI_ARB
on VLV.

v2: Amend commit message with results from experimentation
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

WaFbcNukeOn3DBlt for IVB, HSW.

According BSPec: "Workaround: Do not enable Render Command Streamer tracking for FBC.
Instead insert a LRI to address 0x50380 with data 0x00000004 after the PIPE_CONTROL that
follows each render submission."

v2: Chris noticed that flush_domains check was missing here and also suggested to do
    LRI only when fbc is enabled. To avoid do a I915_READ on every flush lets use the
    module parameter check.

v3: Adding Wa name as Damien suggested.

v4: Ville noticed VLV doesn't support fbc at all and comment came wrong from spec.

v5: Ville noticed than on blt a Cache Clean LRI should be used instead the Nuke one.

v6: Check for flush domain on blt (by Ville).
    Check for scanout dirty (by Chris).

v7: Apply proper fbc_dirty implemented by Chris.

v8: remove unused variables.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pull the code to disable trickle feed for all primary planes into a
separate function.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We disable trickle feed in all the (relevant) clock gating functions,
except ironlake_init_clock_gating(). Copy paste the same code there as
well.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

According to BSpec, trickle feed should be disabled for BW and
mobile CL. Those constraints seem to match all of our gen4 chipsets.

Trickle feed is disabled via the MI_ARB_STATE register instead of
per plane controls on gen4.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The docs say that the trickle feed disable bit is present (for primary
planes only, not video sprites) on CTG, and that it must be set
for ELK. Just set it for all g4x chipsets.

v2: Do it in init_clock_gating too
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Haswell Display audio depends on power well in graphic side, it should
request power well before use it and release power well after use.
I915 will not shutdown power well if it detects audio is using.
This patch protects display audio crash for Intel Haswell C3 stepping board.
Signed-off-by: NWang Xingchao <xingchao.wang@linux.intel.com>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CTG/ILK/SNB/IVB support 4kx2k surfaces. HSW supports 4kx4k, but
without proper front buffer invalidation on the last 2k lines, so
don't enable FBC on these cases for now.

v2: Use gen >= 5, not gen > 4 (Daniel).
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fix the DSPCLK_GATE_D access for VLV. The code incorrectly tried to
poke at the ILK+ version of the register which is at the wrong offset.
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>

The LP watermark registers don't exist on VLV, so don't touch them.
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>

... 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>

PM interrupts have an expanded role on HSW. It helps route the EBOX
interrupts. This patch is necessary to make the existing code which
touches the mask, and enable registers more friendly to other code paths
that also will need these registers.

To be more explicit:
At preinstall all interrupts are masked and disabled. This implies that
preinstall should always happen before any enabling/disabling of RPS or
other interrupts.

The PMIMR is touched by the workqueue, so enable/disable touch IER and
IIR. Similarly, the code currently expects IMR has no use outside of the
RPS related interrupts so they unconditionally set 0, or ~0. We could
use IER in the workqueue, and IMR elsewhere, but since the workqueue
use-case is more transient the existing usage makes sense.

Disable RPS events:
IER := IER & ~GEN6_PM_RPS_EVENTS // Disable RPS related interrupts
IIR := GEN6_PM_RPS_EVENTS // Disable any outstanding interrupts

Enable RPS events:
IER := IER | GEN6_PM_RPS_EVENTS // Enable the RPS related interrupts
IIR := GEN6_PM_RPS_EVENTS // Make sure there were no leftover events
(really shouldn't happen)

v2: Shouldn't destroy PMIIR or PMIMR VEBOX interrupt state in
enable/disable rps functions (Haihao)

v3: Bug found by Chris where we were clearing the wrong bits at rps
disable.
    expanded commit message

v4: v3 was based off the wrong branch

v5: Added the setting of PMIMR because of previous patch update

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At the moment, these values are wiped out anyway by the rps
enable/disable. That will be changed in the next patch though.

v2: Add post install setup to address issue found by Damien in the next
patch.
replaced
WARN_ON(dev_priv->rps.pm_iir != 0);
with rps.pm_iir = 0;

With the v2 of this patch and the deferred pm enabling (which changed
since the original patches) we're now able to get PM interrupts before
we've brought up enabled rps. At this point in boot, we don't want to do
anything about it, so we simply ignore it. Since writing the original
assertion, the code has changed quite a bit, and I believe removing this
assertion is perfectly safe.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: I don't agree with the justification to drop the WARN and
added a FIXME to that effect.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now we compute the results for both 1/2 and 5/6 partitioning and then
use hsw_find_best_result to choose which one to use.

With this patch, Haswell watermarks support should be in good shape.
The only improvement we're missing is the case where the primary plane
is disabled: we always assume it's enabled, so we take it into
consideration when calculating the watermarks.

v2: - Check the latency when finding the best result
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We were previously only setting the WM_PIPE registers, now we are
setting the LP watermark registers. This should allow deeper PC
states, resulting in power savings.

We're only using 1/2 data buffer partitioning for now.

v2: Merge both hsw_compute_pri_wm_* functions (Ville)
v3: - Simplify hsw_compute_wm_results (Ville)
    - Rebase due to changes on the previous patch
v4: Unconfuse wm_lp/level (Ville)
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We were previously calling sandybridge_update_wm on HSW, but the SNB
function didn't really match the HSW specification, so we were just
writing the wrong values.

With this patch, the haswell_update_wm function will set the correct
values for the WM_PIPE registers, but it will still keep all the LP
watermarks disabled.

The patch may look a little bit over-complicated for now, but it's
because much of the infrastructure for setting the LP watermarks is
already in place, so we won't have too much code churn on the patch
that sets the LP watermarks.

v2: - Fix pixel_rate on panel fitter case (Ville)
    - Try to not overflow (Ville)
    - Remove useless variable (Ville)
    - Fix p->pri_horiz_pixels (Paulo)
v3: - Fix rounding errors on hsw_wm_method2 (Ville)
v4: - Fix memcmp bug (Paulo)
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On Haswell, whenever we change the sprites we need to completely
recalculate all the watermarks, because the sprites are one of the
parameters to the LP watermarks, so a change on the sprites may
trigger a change on which LP levels are enabled.

So on this commit we store all the parameters we need to store for
proper recalculation of the Haswell WMs and then call
haswell_update_wm.

Notice that for now our haswell_update_wm function is not really using
these parameters we're storing, but on the next commits we'll use
these parameters.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because we want to call it from the "sprite disable" paths, since on
Haswell we need to update the sprite watermarks when we disable
sprites.

For now, all this patch does is to add the "enable" argument and call
intel_update_sprite_watermarks from inside ivb_disable_plane. This
shouldn't change how the code behaves because on
sandybridge_update_sprite_wm we just ignore the "!enable" case. The
patches that implement Haswell watermarks will make use of the changes
introduced by this patch.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We never check the return values, and there's not much we could do on
errors anyway. Just simplify the signatures. 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>

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>

Group both the HSW/LPT SBI interface and VLV IOSF sideband register
accessor functions into a new file. No functional changes.

v2: also move intel_sbi_{read,write} (Daniel)
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>

Commit 1544d9d5 added a workaround
inside haswell_init_clock_gating and mentioned it is "a workaround for
early silicon revisions and should be removed later". This workaround
is documented in bit 31 of PRI_CTL. I asked Arthur and he mentioned
that setting FORCE_ARB_IDLE_PLANES replaces that workaround for the
newer machines. So use the new one.

Also notice that there's still another workaround for PRI_CTL that
involves WM_DBG, but it's not the one we're reverting. And notice that
we were previously setting WM_DBG_DISALLOW_MULTIPIPE_LP which disables
the LP watermarks when more than one pipe is used, and we really don't
want this because we need the LP watermarks if we want to reach deeper
PC states.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Add a comment for the w/a name Ville dug out of Bspec.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And the SNB_READ_WM0_LATENCY macro is not valid anymore because we
have the "New WM0" at 63:56, so the "Old WM0" could maybe be zero if
the new one is not zero.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Remove the "placeholder" comment and set the actual value described by
the specification. We still don't enable IPS, but it won't hurt to
already have the value set here.

While at it, fully set the register value instead of just masking the
values we're changing.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Resolve conflict due to reordered patches.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the "*8"  calculation to the left side so we don't propagate
rounding errors. Also use DIV_ROUND_CLOSEST because that's what the
spec says we need to do.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... instead of mode->crtc_display. The spec says "pipe horizontal
total number of pixels" and the "Haswell Watermark Calculator" tool
uses the "Pipe H Total" instead of "Pipe H Src" as the value.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The spec says the linetime watermarks must be programmed before
enabling any display low power watermarks, but we're currently
updating the linetime watermarks after we call intel_update_watermarks
(and only at crtc_mode_set, not at crtc_{enable,disable}). So IMHO the
best way guarantee the linetime watermarks will be updated before the
low power watermarks is inside the update_wm function, because it's
the function that enables low power watermarks. And since Haswell is
the only platform that has linetime watermarks, let's completely kill
the "intel_update_linetime_watermarks" abstraction and just use the
intel_update_watermarks abstraction by creating haswell_update_wm.

For now haswell_update_wm is still calling sandybridge_update_wm, but
in the future I plan to implement a function specific to Haswell.

v2: - Rename patch
    - Disable LP watermarks before changing linetime WMs (Chris)
    - Add a comment explaining that this is just temporary code.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This should prevent mode set failures on LPT.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Pimp the w/a tag to fit into Damien's new scheme.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There was a race between Rodrigo writing those patches and me
formalizing the addition of platform tags. This patches fixes it.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Display register 46500h bit 23 must be set to 1b for the entire time that
Frame Buffer Compression is enabled.

v2: Ville suggested to enable it back when disabling fbc to avoid wasting
    power.

v3: RMW to preserve other bits (by Ville)
v4: Fix from Ville: sed &/| at RMW
v5: Too far on sed.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
[danvet: Insert missing space that checkpatch spotted.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Display register 420B0h bit 22 must be set to 1b for the entire time that
Frame Buffer Compression is enabled.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch introduce Frame Buffer Compression (FBC) support for HSW.
FBC is tied to primary plane A in HSW.

v2: Ville pointed out docs say FBC must be disabled before disabling
    the plane on HSW.
v3: Really enabling it by default at HSW.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Display register 42020h bit 9 must be set to 1b for the entire time that
Frame Buffer Compression is enabled.

v2: RMW to preserve other bits (by Ville)
v3: Fix from Ville: sed &/| at RMW
v4: Too far on sed.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Display register 42000h bit 22 must be set to 1b for the entire time that
Frame Buffer Compression is enabled.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch introduce Frame Buffer Compression (FBC) support for IVB,
without enabling it by default.
It adds a new function gen7_enable_fbc to avoid getting
ironlake_enable_fbc messed with many IS_IVYBRIDGE checks.

v2: Fixes from Ville.
     	*  Fix Plane. FBC is tied to primary plane A in HSW
    	*  Fix DPFC initial write to avoid let trash on the register.
v3: Checking for bad plane on intel_update_fbc() as Chris suggested.
v4: Ville pointed out that according to BSpec FBC_CTL bits 0:3 must be 0.
v5: Up to v4 this work was entirely focused on Haswell. However Ville
    noticed I could reuse the FBC work done for HSW and get FBC for free
    at Ivybridge. So it makes more sense enable FBC for IVB first.
    FBC for HSW comming on next patches. We are just not enabling it by
    default on IVB.
v6: Fix confused commit name (by Matt Turner).
v7: Remove gtt_offset shift since it is page aligned byte offset (by Ville).

Cc: Matt Turner <mattst88@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
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>

In some cases, we may not need GTT address space allocated to a stolen
object, so allow passing -1 to the preallocated function to indicate as
much.

v2: remove BUG_ON(gtt_offset & 4095) now that -1 is allowed (Ville)
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

But we need to get the right stolen base and make pre-allocated objects
for BIOS stuff so we don't clobber it.  If the BIOS hasn't allocated a
power context, we allocate one here too, from stolen space as required
by the docs.

v2: fix stolen to phys if ladder (Ben)
    keep BIOS reserved space out of allocator altogether (Ben)
v3: fix mask of stolen base (Ben)
v4: clean up preallocated object on unload (Ben)
    don't zero reg on unload (Jesse)
    fix mask harder (Jesse)
v5: use unref for freeing stolen bits (Chris)
    move alloc/free to intel_pm.c (Chris)
v6: NULL pctx at disable time so error paths work (Ben)
v7: use correct PCI device for config read (Jesse)
Reviewed-by: NBen Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If the calculated FBC watermark is no good, we simply disable FBC
watermarks. But we fail to re-enable them later if the calculated
watermark becomes good again. Fix that, but remember to leave FBC
watermarks disabled on ILK since that's required by some workarounds.

v2: Fix checkpatch complaint
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>