VGA detection requires the reference clock to be on, so make sure this
is the case.

This fixes VGA hotplug/manual detection where all pipes are off and so
we would normally disable all clocks.

v2:
- Instead of disabling PSR clock gating, force the reference clock on
  through the DPLL_A register. (Kin Chan S <kin.s.chan@intel.com>)

v3:
- Move enabling of the clock to intel_reset_dpio() and use the DPLL_B
  register instead, where we already have a similar tweak for the CRI
  clock. (Ville)
Reported-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_init_dpio() isn't called during resume, so we won't set the CRI
clock enable bit during that time. Move the enabling to
intel_reset_dpio() instead.

Note that the HW reset value for this bit is 1, so probably this patch
won't make any difference. We should still make the setting explicit,
since BIOS could change things under us.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The WA is mentioned in HSW's GAMMA_MODE register documentation, but
not on on BDW's documentation, so let's assume it is not needed there.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

That we can use for debugging purposes.

v2: Use designated initializers for the 'names' array (Paulo Zanoni,
    Jani Nikula).
    Add a check in case the array has a hole (which can now remain
    unnoticed with designated initializers) (Jani Nikula)

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (for v1)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In some cases we have more than 1 connector associated to an encoder
(e.g., SDVO, Haswell DP/HDMI) and we can only set a mode for one of
these connectors. If we only allowed modesets for connected connectors
we would never need this patch, but since we do allow modeset for
disconnected connectors we may see user space trying to set modes on
the two connectors attached to the same encoder, so we need to forbid
that.

This problem can be reproduced by running the following
intel-gpu-tools test case:
  ./kms_setmode --run-subtest clone-exclusive-crtc

Thanks to Daniel Vetter for providing a version of this patch on
pastebin.

Credits-to: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So shuffle the checks around a bit. Also give all the structs and
functions proper prefixes: i830_ for the dual-pipe mobile platforms
and i845_ for the two single-pipe desktop platforms.

Note that the max fifo value isn't actually correct for the i830M, but
since we don't frob the fifo split we don't actually need it. This is
different for some gen3 devices where we need the full fifo for self
refresh mode.

Cc: Thomas Richter <richter@rus.uni-stuttgart.de>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

My OCD just couldn't let this slide. Spotted while reviewing Ville's
patch to only flip planes when we have FBC.

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>

Looks like 830M doesn't quite like it when you try to move a plane from
one pipe to another. It seems that the plane's old pipe has to be active
even if the plane is already disabled, otherwise the relevant register
just won't accept new values.

The following commit:

 commit 1f1c2e24
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Thu Nov 28 17:30:01 2013 +0200

    drm/i915: Swap primary planes on gen2 for FBC

caused a regression on 830M. It will attempt to swap the planes when the
driver is loaded, but at that time only pipe A might be active, so plane
A gets disabled, but plane B won't get enabled since pipe B is not
active when we try to move the plane over to pipe A.

There's no reason to swap planes on 830M since it doesn't support
FBC. Change the logic a bit to limit the plane swapping to platforms
which actually support FBC. This should avoid getting a black screen on
830M.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

LPT does have PCH refclk, but it's different form the IBX/CPT/PPT one
and doesn't use the same structs. It is wrong to have a message saying
that "LPT does not has PCH refclk" (sic). While at it, signal that we
only want this function on IBX/CPT/PPT by renaming it and adding a
WARN.

On HSW we also print "0 shared PLLs initialized", but we *do* have
shared PLLs on HSW (LCPLL, WRPLL, SPLL) and we *do* initialize them.
We just don't use "struct intel_shared_dpll". So remove the debug
message.

In the future we may want to rename all that "intel shared pll" code
to "ibx shared pll", but I'll leave this to another patch.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

According to Art, we don't have a way to read back the state reliably at
runtime, through the control reg or the mailbox, at least not without risking
disabling it again.  So drop the readout and checking on BDW.

v2: drop TODO comment (Paulo)
    move POSTING_READ of control reg under HSW branch in disable (Paulo)
    always report IPS as enabled on BDW (Paulo)

References: https://bugs.freedesktop.org/show_bug.cgi?id=71906Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was introduced in:

commit 7c4a395f
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Wed Oct 9 19:17:56 2013 +0300

    drm/i915: Don't re-compute pipe watermarks except for the affected pipe

and I missed fixing it in:

commit fec8cba3
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Wed Nov 27 11:10:26 2013 -0800

    drm/i915: use crtc_htotal in watermark calculations to match fastboot v2

It's needed for ILK+ platforms to fastboot without crashing on a divide
by 0 after a DPMS on action.

Note: Ville mentioned in his review that this confusion seems to go
down to the original introduction of this code in

commit 801bcfff
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Fri May 31 10:08:35 2013 -0300

    drm/i915: properly set HSW WM_PIPE registers

So it seems to have been missed both in the fastboot patch and in the
3d mode suppport (where only crtc_htotal reflects the real pipe
width).
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Add note based on Ville's review.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When fastbooting, we read out the pipe timings early on, and then in a
panel fitted config, disable the fitter later.  But we weren't updating
the pipe src h/w, which meant the mouse cursor was clipped to the
pfitted size rather than the native size set later.  Fix that up so the
cursor is visible in the new mode.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise we won't check the state until the next DPMS transition, which
may never happen.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Avoid duplicating the same piece of code several times by separating
the watemark vfunc setup from the init_clock_gating vfunc setup on PCH
platforms.
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>

We forgot to intialize the watermark vfuncs for BDW, and hence the
watermarks were never updated.
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>

Looks like I forgot to update the ILK/SNB/IVB watermark patches to deal
with BDW. Add the relevant BDW checks to make sure we take the HSW
codepaths on BDW as well.
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>

We're iterating over the CPU transcoders, so check for the correct
power domain.

This fixes many "unclaimed register" error messages.

This can be reproduced by the IGT test mentioned below, but we still
get a FAIL when we run it.

Testcase: igt/kms_lip/flip-vs-panning-vs-hang
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In very rare cases (such as a memory failure stress test) it is possible
to fill the entire ring without emitting a request. Under this
circumstance, the outstanding request is flushed and waited upon. After
space on the ring is cleared, we return to emitting the new command -
except that we just cleared the seqno allocated for this operation and
trigger the sanity check that a request is only ever emitted with a
valid seqno. The fix is to rearrange the code to make sure the
allocation of the seqno for this operation is after any required flushes
of outstanding operations.

The bug exists since the preallocation was introduced in
commit 9d773091
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Nov 27 16:22:52 2012 +0000

    drm/i915: Preallocate next seqno before touching the ring
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Multiple definitions show up multiple times in modinfo output.

There's already an identical one in i915_drv.c along with other MODULE_*
definitions, so drop the lone one in intel_fbdev.c.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The bug from gen6_ppgtt_insert_entries() was replicated into
gen8_ppgtt_insert_entries(). This applies the fix for the OOPS from the
previous patch to the gen8 routine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

[   89.237347] BUG: unable to handle kernel paging request at ffff880096326000
[   89.237369] IP: [<ffffffff81347227>] gen6_ppgtt_insert_entries+0x117/0x170
[   89.237382] PGD 2272067 PUD 25df0e067 PMD 25de5c067 PTE 8000000096326060
[   89.237394] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[   89.237404] CPU: 1 PID: 1981 Comm: gem_concurrent_ Not tainted 3.13.0-rc4+ #639
[   89.237411] Hardware name: Intel Corporation 2012 Client Platform/Emerald Lake 2, BIOS ACRVMBY1.86C.0078.P00.1201161002 01/16/2012
[   89.237420] task: ffff88024c038030 ti: ffff88024b130000 task.ti: ffff88024b130000
[   89.237425] RIP: 0010:[<ffffffff81347227>]  [<ffffffff81347227>] gen6_ppgtt_insert_entries+0x117/0x170
[   89.237435] RSP: 0018:ffff88024b131ae0  EFLAGS: 00010286
[   89.237440] RAX: ffff880096325000 RBX: 0000000000000400 RCX: 0000000000001000
[   89.237445] RDX: 0000000000000200 RSI: 0000000000000001 RDI: 0000000000000010
[   89.237451] RBP: ffff88024b131b30 R08: ffff88024cc3aef0 R09: 0000000000000000
[   89.237456] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88024cc3ae00
[   89.237462] R13: ffff88024a578000 R14: 0000000000000001 R15: ffff88024a578ffc
[   89.237469] FS:  00007ff5475d8900(0000) GS:ffff88025d020000(0000) knlGS:0000000000000000
[   89.237475] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   89.237480] CR2: ffff880096326000 CR3: 000000024d531000 CR4: 00000000001407e0
[   89.237485] Stack:
[   89.237488]  ffff880000000000 0000020000000000 ffff88024b23f2c0 0000000100000000
[   89.237499]  0000000000000001 000000000007ffff ffff8801e7bf5ac0 ffff8801e7bf5ac0
[   89.237510]  ffff88024cc3ae00 ffff880248a2ee40 ffff88024b131b58 ffffffff813455ed
[   89.237521] Call Trace:
[   89.237528]  [<ffffffff813455ed>] ppgtt_bind_vma+0x3d/0x60
[   89.237534]  [<ffffffff8133d8dc>] i915_gem_object_pin+0x55c/0x6a0
[   89.237541]  [<ffffffff8134275b>] i915_gem_execbuffer_reserve_vma.isra.14+0x5b/0x110
[   89.237548]  [<ffffffff81342a88>] i915_gem_execbuffer_reserve+0x278/0x2c0
[   89.237555]  [<ffffffff81343d29>] i915_gem_do_execbuffer.isra.22+0x699/0x1250
[   89.237562]  [<ffffffff81344d91>] ? i915_gem_execbuffer2+0x51/0x290
[   89.237569]  [<ffffffff81344de6>] i915_gem_execbuffer2+0xa6/0x290
[   89.237575]  [<ffffffff813014f2>] drm_ioctl+0x4d2/0x610
[   89.237582]  [<ffffffff81080bf1>] ? cpuacct_account_field+0xa1/0xc0
[   89.237588]  [<ffffffff81080b55>] ? cpuacct_account_field+0x5/0xc0
[   89.237597]  [<ffffffff811371c0>] do_vfs_ioctl+0x300/0x520
[   89.237603]  [<ffffffff810757a1>] ? vtime_account_user+0x91/0xa0
[   89.237610]  [<ffffffff810e40eb>] ?  context_tracking_user_exit+0x9b/0xe0
[   89.237617]  [<ffffffff81083d7d>] ? trace_hardirqs_on+0xd/0x10
[   89.237623]  [<ffffffff81137425>] SyS_ioctl+0x45/0x80
[   89.237630]  [<ffffffff815afffa>] tracesys+0xd4/0xd9
[   89.237634] Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 0f 1f 84 00 00 00 00 00 83 45 bc 01 49 8b 84 24 78 01 00 00 65 ff 0c 25 e0 b8 00 00 8b 55 bc <4c> 8b 2c d0 65 ff 04 25 e0 b8 00 00 49 8b 45 00 48 c1 e8 2d 48
[   89.237741] RIP  [<ffffffff81347227>] gen6_ppgtt_insert_entries+0x117/0x170
[   89.237749]  RSP <ffff88024b131ae0>
[   89.237753] CR2: ffff880096326000
[   89.237758] ---[ end trace 27416ba8b18d496c ]---

This bug dates back to the original introduction of the
gen6_ppgtt_insert_entries()
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Dropped cc: stable since without full ppgtt there's no way
we'll access the last page directory with this function since that
range is occupied (only in the allocator) with the ppgtt pdes. Without
aliasing we can start to use that range and blow up.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The iommu and gfx on Ironlake do not like each other and require a
big hammer to prevent hard machine hangs. In

commit 5c042287
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Mon Oct 17 15:51:55 2011 -0700

    drm/i915: ILK + VT-d workaround

we added the workaround, but never emitted any debug message that it was
active. Doing so should help identify known performance regressions.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since get_pid_task() grabs a reference on the task_struct, we have to drop the
refcount after reading that task's comm name. Use pid_task() with RCU instead.

Also, avoid directly reading like pid_task()->comm because
pid_task() will return NULL if the task have already exit()ed.

This patch fixes both problems.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

But only when we indeed set up a gtt mapping. We need this since the
vma also holds a pages_pin_count, on top of the unconditional
pages_pin_count we grab for all stolen objects (to avoid swap-out).

This should avoid a pages_pin_count underrun when cleaning up
framebuffers objects taken over from the BIOS.

Chris mentioned in his review that this bug even predates the vma
conversion.
Reported-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We use this hook starting from ILK onwards, so change the prefix
accordingly. Also rename functions/struct names used from
haswell_update_wm that are relevant to ILK already.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Apparently always enabling the sprite scaler magically made
sprites work on ILK in the past.

I think the real reason for the failure was missing sprite
watermark programming, and enabling the scaler effectively
disabled LP1+ watermarks, which was enough to keep things going.
Or it might be that the hardware more or less ignores watermarks
for scaled sprites since things seem to work even if I leave
sprite watermarks at 0 and disable all other planes except the
sprite.

In any case, we left the scaler always on but then failed to
check whether we might be exceeding the scaler's source size
limits. That caused the sprite to fail when a sufficiently
large unscaled image was being displayed.

Now that we're getting proper watermark programming for ILK, we
can keep the scaler disabled unless we need to do actual scaling.

This reverts commit 8aaa81a1.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As the watermark registers aren't double bufferd, clearing the
watermarks immediately after writing the sprite registers can be
hazardous.

Until we have something better, add a wait for vblank between the
two steps to make sure the sprite no longer needs the watermark
levels before we clear them.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When color keying is used, the primary may not be invisible even though
the sprite fully covers it. So check for color keying before deciding to
disable the primary plane.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We now have a very clear method of disabling LP1+ wartermarks,
and we can actually detect if we actually did disable them, or
if they were already disabled. Use that to clean up the
WaCxSRDisabledForSpriteScaling:ivb handling.

I was hoping to apply the workaround in a way that wouldn't
require a blocking wait, but sadly IVB really does appear to
require LP1+ watermarks to be off for an entire frame before
enabling sprite scaling. Simply disabling LP1+ watermarks
during the previous frame is not enough, no matter how early
in the frame we do it :(
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The new HSW watermark code can now handle ILK/SNB/IVB as well, so
switch them over. Kill the old code.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ILK doesn't like if we just write the LP1+ watermarks registers with 0.
We need to just disable the watermarks by clearing the enable bit. Use
that method also when disabling LP1+ watermarks in init_clock_gating.

It looks like disabling the sprite LP1 watermarks can cause underruns
even if we just toggle the WM1S_LP_EN bit. So treat that bit like the
actual watermark numbers and avoid setting it to 0 immediately.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Linetime watermarks don't exist on ILK/SNB/IVB, so don't compute them
except on HSW.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ILK has a bunch of issues with FBC. First of all, BSpec tells us that
FBC WM should never be enabled. Secondly when FBC is enabled
with FBC WM disabled, LP2+ watermarks must be disabled.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Multi-pipe LP1+ watermarks are a HSW+ feature, so let's not do it on
earlier generations.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On ILK disabling LP1+ watermarks must be done carefully to avoid
underruns. If we just write 0 to the register in the middle of the scan
cycle we often get an underrun. So instead we have to leave the actual
watermark levels in the register intact, and just toggle the enable bit.

Presumably the hardware takes a while to get out of low power mode, and
so the watermark level need to stay valid until that time.

We also have to be careful with the WM1S_LP_EN bit. It seems the
hardware more or less treats it like the actual watermarks numbers, and
so we must not toggle it too soon. Just leave it alone when disabling
the LP1+ watermarks.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ILK/SNB don't have LP2+ watermarks for sprites. Also the LP1 sprite
watermark register has its own enable bit. Take these differences
into account when programming the LP1+ registers.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On ILK/SNB only LP0/1 watermarks can be enabled when sprites are
enabled, and on ILK/SNB/IVB sprite scaling is limited to LP0 only.

So we can avoid computing the extra levels we're never going to use.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a new function  ilk_wm_lp_latency() which will tell us what to write
into the WM_LPx register latency field. HSW is different from erlier
gens in this regard.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>