The changes since the sequence block v2 are:

* The whole MIPI bios data block has a separate 32-bit size field since
  v3, stored after the version. This facilitates big sequences.

* The size of the panel specific sequence blocks has grown to 32
  bits. This facilitates big sequences.

* The elements within sequences now have an 8-bit size field following
  the operation byte. This facilitates skipping unknown new operation
  bytes, i.e. forward compatibility.

v2 (of the patch): use DRM_ERROR for unknown operation byte
v3 (of the patch): even more bounds checking (Ville)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452518102-3154-1-git-send-email-jani.nikula@intel.com

New sequences, new operations within sequences.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/96335b9fb875f79882d694360bff060251bd2f17.1450702954.git.jani.nikula@intel.com

Don't choke on unknown elements when we do know how to skip them.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452518948-16469-1-git-send-email-jani.nikula@intel.com

Properly parse the new sequences added in MIPI sequence block v2.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/cc1551bdfc4392d02413b78179f3a65c786c75ab.1450702954.git.jani.nikula@intel.com

Add parsing of the i2c element, defined in MIPI sequence block v2. Drop
the status operation byte while at it, that does not exist.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/d8a2998977feee2f5b5ad609aaca787adfb41479.1450702954.git.jani.nikula@intel.com

If we go into suspend with unclaimed access detected,
it would be nice to catch that access on a next suspend path.
So instead of just notifying about it, arm the unclaimed
mmio checks on suspend side.

We want to keep the asymmetry on resume, as if it was
on resume path, it was not driver that is responsible so
no point in arming mmio debugs.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1452261080-6979-2-git-send-email-mika.kuoppala@intel.com

With commit 8ac3e1bb ("drm/i915: Add non claimed mmio checking
for vlv/chv") we now have chv/vlv support in place for detecting
unclaimed access. Also the perf hit of extra mmio read
is now only suffered if mmio_debug is set.

This allows us to stuff the macro for unclaimed reg
detection inside a generic gen6 register access, as now all
gens using these macros uses also unclaimed debugs, the one
exception being snb. We gain more clean and generic macros
and only downside is that snb will suffer one branch perf hit
without upside.

Note that the hsw write path debug register check now
happens before fifo check, but this should not make
any real difference.

As vlv/chv use the generic gen6 access macros, the consequence
is that they gain the mmio_debug feature.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1452261080-6979-1-git-send-email-mika.kuoppala@intel.com

This fixes a spurious warning from an integer overflow on 64-bits systems.
The function may return MAX_SCHEDULE_TIMEOUT which gets truncated to -1.

Explicitly handling this by casting to lret fixes it.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reported-and-tested-by: NJoseph Yasi <joe.yasi@gmail.com>
Tested-by: NAndreas Reis <andreas.reis@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 3c28ff22 ("i915: wait for fence in prepare_plane_fb")
Link: http://patchwork.freedesktop.org/patch/msgid/5666EEC8.2000403@linux.intel.com

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Extend the same reasoning as in the patch listed below.  It's not an
error for the workaround list to be empty if no workarounds are needed.

    commit 02235808
    Author: Francisco Jerez <currojerez@riseup.net>
    Date:   Wed Oct 7 14:44:01 2015 +0300
        drm/i915: Don't warn if the workaround list is empty.
Signed-off-by: NWayne Boyer <wayne.boyer@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452129330-3484-2-git-send-email-rodrigo.vivi@intel.com

When adding IS_KABYLAKE definition I didn't included the
DC states related because I was planing to include them
with the patch that fixes DMC firmware loading, but I
forgot them.

Meanwhile this runtime pm code changed a lot for
Skylake.

Well, I didn't expect that this would crash the machine
and I just noticed now that Sarah warned me our driver
wasn't working. Thanks Sarah.

Michel had found the main error first and his
fix had better details on the history and got
merged already:

commit 16fbc291
Author: Michel Thierry <michel.thierry@intel.com>
Date:   Wed Jan 6 12:08:36 2016 +0000

    drm/i915/kbl: Enable PW1 and Misc I/O power wells

This one is a follow-up adding the other remaining
missing pieces.

v2: Rebased on top of Michel's patch as explained above.

Cc: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452214179-22361-1-git-send-email-rodrigo.vivi@intel.com

The dsi_rr_formula() function has been unused for almost two years,
since

commit 44d4c6ee
Author: Shobhit Kumar <shobhit.kumar@intel.com>
Date:   Tue Dec 10 12:14:56 2013 +0530

    drm/i915: Compute dsi_clk from pixel clock

citing the reason as pixel clock based calculation being recommended in
the MIPI host controller documentation. Remove the dead code, we can
always bring it back if it's needed.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452249940-2605-2-git-send-email-jani.nikula@intel.com

Hide away the platform differences in intel_dsi_get_pckl() within
intel_dsi_pll.c. No functional changes.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452249940-2605-1-git-send-email-jani.nikula@intel.com

Imre mentioned that chv might also have capability to
track unclaimed mmio accesses. Ville added that
both chv and vlv has this capability and he had already
made this way back [1]. Mimic what Ville's patch does
but adapt on top of less frequent mmio accesses by
omitting checking always on reg writes.

This patch is untested as of now.

v2: overflow handling and posting omitted (Ville)

References: [1] http://lists.freedesktop.org/archives/intel-gfx/2013-May/027599.html
Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450201542-22918-1-git-send-email-mika.kuoppala@intel.com

Remove char* assignments and add branching hint and
also constify the parameters.

This results in a 35 bytes shorter fast path, so author
boldly assumes it helps without doing in-depth assembly
analysis.

v2: use WARN's branching (Chris), commit name (Joonas)

Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450189512-30360-5-git-send-email-mika.kuoppala@intel.com

We have done unclaimed register access check in normal
(mmio_debug=0) mode once per write. This adds probability
of finding the exact sequence where we did the bad access, but
also adds burden to each write.

As we have mmio_debug available for more fine grained analysis,
give up accuracy of detecting correct spot at the first occurrence
by doing the one shot detection and arming of mmio_debug in hangcheck
and in modeset. This removes the write path performance burden.

v2: Remove gratuitous DRM_DEBUG and return value, comments (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450250808-14864-1-git-send-email-mika.kuoppala@intel.com

If something, the usual suspect being bios, access hw
behind our back, don't let it slide into situation where
normal register access will detect this and spit out
a warn on into dmesg. On some bdw bioses this happens
during igt/bat run always and as there is not much we can
do about it, its better just to detect and flush this
explicitly on resume and only print a debug message.

v2: use DRM_DEBUG_DRIVER (Chris)
v3: s/access/mmio, s/prior/prior to, s/dev/dev_priv

Testcase: igt/pm_rpm/basic-rte
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <przanoni@gmail.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[Mika: fixed merge conflict]
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450189512-30360-3-git-send-email-mika.kuoppala@intel.com

Currently interrupt code is the only place checking
for the unclaimed register access prior to actual register
macros using the same functionality. Rename the function
and make it return bool so that the possible error message
context is clear in the caller side. The motivation is to allow
usage of unclaimed detection on arbitrary places.

v2: rebase, s/access/mmio, s/dev/dev_priv
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450189512-30360-2-git-send-email-mika.kuoppala@intel.com

Access the unclaimed reg detection register through
one helper which also does cleanup. Note that we now access
the register only if the platform has the actual non claimed
access bit. This prevents reading the register with gens that
doesn't have the register or the unclaimed bit,
when debug_mmio > 0.

Note that we post after clearing the bit. This makes sure
that the next unclaimed write access would get detected
also if it happened right after clearing, and not fold
into the previous detection.

v2: s/unclaimed_reg_access/check_for_unclaimed_mmio (Chris)
    debug log on unclaimed detection on uncore init (Joonas)

v3: remove posting read (Ville)

Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450200287-24080-1-git-send-email-mika.kuoppala@intel.com

If head seems stuck and engine in question is rcs,
inspect subunit state transitions from undone to done,
before deciding that this really is a hang instead of limited
progress. Only account the transitions of subunits from
undone to done once, to prevent unstable subunit states
to keep us falsely active.

As this adds one extra steps to hangcheck heuristics,
before hang is declared, it adds 1500ms to to detect hang
for render ring to a total of 7500ms. We could sample
the subunit states on first head stuck condition but
decide not to do so only in order to mimic old behaviour. This
way the check order of promotion from seqno > atchd > instdone
is consistently done.

v2: Deal with unstable done states (Arun)
    Clear instdone progress on head and seqno movement (Chris)
    Report raw and accumulated instdone's in in debugfs (Chris)
    Return HANGCHECK_ACTIVE on undone->done

References: https://bugs.freedesktop.org/show_bug.cgi?id=93029
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448985372-19535-1-git-send-email-mika.kuoppala@intel.com

No functional changes.

That state the obvious and just duplicate the place we
need to change whenever the table is updated. So let's clean it.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452021535-22641-1-git-send-email-rodrigo.vivi@intel.com

When reviewing DDI translation table I noticed few changes we
haven't incorporated yet and it is always good to follow latest
spec.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452009511-15064-1-git-send-email-rodrigo.vivi@intel.com

When debuging an intermittent corrupted screen I suspected on DDI
translation table and checked we are out of date with the spec.

I'm not sure this will fix my bug yet, but it is always good to follow
the spec.

v2: Ville caught a switched i-boost value. Thanks!

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452021087-21673-1-git-send-email-rodrigo.vivi@intel.com

This fixes reprobing of display connectors on resume.  After some
talking with danvet on IRC, I learned that calling
drm_helper_hpd_irq_event() does actually trigger a full reprobe of each
connector's status. It turns out this is the actual reason reprobing on
resume hasn't been working (this was observed on a T440s):

	- We call hpd_init()
	- We check each connector for a couple of things before marking
	  connector->polled with DRM_CONNECTOR_POLL_HPD, one of which is an
	  active encoder. Of course, a disconnected port won't have an
	  active encoder, so we don't add the flag to any of the
	  connectors.
	- We call drm_helper_hpd_irq_event()
	- drm_helper_irq_event() checks each connector for the
	  DRM_CONNECTOR_POLL_HPD flag. The only one that has it is eDP-1,
	  so we skip reprobing each connector except that one.

In addition, we also now avoid setting connector->polled to
DRM_CONNECTOR_POLL_HPD for MST connectors, since their reprobing is
handled by the mst helpers. This is probably what was originally
intended to happen here.

Changes since V1:
* Use the explanation of the issue as the commit message instead
* Change the title of the commit, since this does more then just stop a
  check for an encoder now
* Add "Fixes" line for the patch that introduced this regression
* Don't enable DRM_CONNECTOR_POLL_HPD for mst connectors

Changes since V2:
* Put patch changelog above Signed-off-by
* Follow Daniel Vetter's suggestion for making the code here a bit more
  legible

Fixes: 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)")
Cc: stable@vger.kernel.org
Signed-off-by: NLyude <cpaul@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452181408-14777-1-git-send-email-cpaul@redhat.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is a useful thing to have around as a function because the mechanism may
change in the future.

There is a net increase in LOC here, and it will continue to be the case on GEN8
and GEN9 - but future GENs may have an alternate mechanism for doing this.
Signed-off-by: NBen Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452018609-10142-4-git-send-email-benjamin.widawsky@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is no point in emitting a WARN since the backtrace will always be the
same. Errors have actually become easier to spot given the large number of WARNs
which exist today in modesetting paths.
Signed-off-by: NBen Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452018609-10142-3-git-send-email-benjamin.widawsky@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I think this patch is a worthwhile cleanup even if it might look only marginally
useful. It gets more useful in upcoming patches and for handling of future GEN
platforms.

The only non-mechanical part of this is the removal of the extra & operation on
the ring->next_context_status_buffer. This is safe because right above this, we
already did a modulus operation.
Signed-off-by: NBen Widawsky <benjamin.widawsky@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452018609-10142-2-git-send-email-benjamin.widawsky@intel.comReviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

My kbl stopped working because of this.

Fixes regression from
commit 2f693e28
Author: Damien Lespiau <damien.lespiau@intel.com>
Date:   Wed Nov 4 19:24:12 2015 +0200
    drm/i915: Make turning on/off PW1 and Misc I/O part of the init/fini
    sequences

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452082116-16770-1-git-send-email-michel.thierry@intel.comReviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With sprites, cursors and primary planes taking the atomic state
this is now unused. It's removed in a separate commit to allow
a revert.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-8-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Pass in the atomic states to allow for proper updates.
This removes uses of intel_crtc->config and direct access
to plane->state.

This breaks the last bit of kgdboc, but that appears to be dead code.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-7-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Cursor planes grab the state from plane->state instead of the state
that was passed. The only updates are atomic now, so use the plane_state
that's passed in.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-6-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Update cursor_addr when disable_plane is called.
This is required to make commit_cursor_plane take a
crtc_state and a plane_state.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-5-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

This is duplicated with intel_check_cursor_plane, and with all
non-atomic paths removed this should be dead code.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-4-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Use update_plane and disable_plane directly.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Don't use plane->state directly, use the pointer from commit_plane.

Changes since v1:
- Fix uses of plane->state->rotation and color key to use the passed state too.
- Only pass crtc_state and plane_state to update_plane.
Changes since v2:
- Rebased.
Changes since v3:
- Small whitespace changes and only assign 1 variable per line.
- Constify plane_state and crtc_state. (vsyrjala)
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-2-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

In addition to calculating final watermarks, let's also pre-calculate a
set of intermediate watermark values at atomic check time.  These
intermediate watermarks are a combination of the watermarks for the old
state and the new state; they should satisfy the requirements of both
states which means they can be programmed immediately when we commit the
atomic state (without waiting for a vblank).  Once the vblank does
happen, we can then re-program watermarks to the more optimal final
value.

v2: Significant rebasing/rewriting.

v3:
 - Move 'need_postvbl_update' flag to CRTC state (Daniel)
 - Don't forget to check intermediate watermark values for validity
   (Maarten)
 - Don't due async watermark optimization; just do it at the end of the
   atomic transaction, after waiting for vblanks.  We do want it to be
   async eventually, but adding that now will cause more trouble for
   Maarten's in-progress work.  (Maarten)
 - Don't allocate space in crtc_state for intermediate watermarks on
   platforms that don't need it (gen9+).
 - Move WaCxSRDisabledForSpriteScaling:ivb into intel_begin_crtc_commit
   now that ilk_update_wm is gone.

v4:
 - Add a wm_mutex to cover updates to intel_crtc->active and the
   need_postvbl_update flag.  Since we don't have async yet it isn't
   terribly important yet, but might as well add it now.
 - Change interface to program watermarks.  Platforms will now expose
   .initial_watermarks() and .optimize_watermarks() functions to do
   watermark programming.  These should lock wm_mutex, copy the
   appropriate state values into intel_crtc->active, and then call
   the internal program watermarks function.

v5:
 - Skip intermediate watermark calculation/check during initial hardware
   readout since we don't trust the existing HW values (and don't have
   valid values of our own yet).
 - Don't try to call .optimize_watermarks() on platforms that don't have
   atomic watermarks yet.  (Maarten)

v6:
 - Rebase

v7:
 - Further rebase

v8:
 - A few minor indentation and line length fixes

v9:
 - Yet another rebase since Maarten's patches reworked a bunch of the
   code (wm_pre, wm_post, etc.) that this was previously based on.

v10:
 - Move wm_mutex to dev_priv to protect against racing commits against
   disjoint CRTC sets. (Maarten)
 - Drop unnecessary clearing of cstate->wm.need_postvbl_update (Maarten)

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452108870-24204-1-git-send-email-matthew.d.roper@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

We still keep getting

[    4.249930] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!

This reverts

commit 820da7ae
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Nov 25 16:47:23 2015 +0200

    Revert "drm/i915: shut up gen8+ SDE irq dmesg noise"

which in itself is a revert, so this is just doing

commit 97e5ed11
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Oct 23 10:56:12 2015 +0200

    drm/i915: shut up gen8+ SDE irq dmesg noise

all over again. I'll stop pretending I understand what's going on like I
did when I thought I'd fixed this for good in

commit 6a39d7c9
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Nov 25 16:47:22 2015 +0200

    drm/i915: fix the SDE irq dmesg warnings properly
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Reference: http://mid.gmane.org/20151213124945.GA5715@nuc-i3427.alporthouse.com
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92084
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 820da7ae ("Revert "drm/i915: shut up gen8+ SDE irq dmesg noise"")
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452155350-14658-1-git-send-email-jani.nikula@intel.com

This prevents a unnecessary modeset on a dell XPS 13 (2016).

N is always a power of 2, which means that for fuzzy matching we should
compare for inequality on the n values, then do fuzzy matching on the m
values.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Tested-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/568D0E93.304@linux.intel.com

Although we can do a good job of reading out hardware state, the
graphics firmware may have programmed the watermarks in a creative way
that doesn't match how i915 would have chosen to program them.  We
shouldn't trust the firmware's watermark programming, but should rather
re-calculate how we think WM's should be programmed and then shove those
values into the hardware.

We can do this pretty easily by creating a dummy top-level state,
running it through the check process to calculate all the values, and
then just programming the watermarks for each CRTC.

v2:  Move watermark sanitization after our BIOS fb reconstruction; the
     watermark calculations that we do here need to look at pstate->fb,
     which isn't setup yet in intel_modeset_setup_hw_state(), even
     though we have an enabled & visible plane.

v3:
 - Don't move 'active = optimal' watermark assignment; we just undo
   that change in the next patch anyway.  (Ville)
 - Move atomic helper locking fix to separate patch.  (Maarten)

v4:
 - Grab connection_mutex before calling atomic helper to duplicate
   state.  The connector loop inside the helper will throw a WARN
   if we don't hold something to protect the connector list (and the
   helper itself doesn't try to lock the list).
 - Make failure to calculate watermarks for inherited state a WARN()
   since it probably indicates a serious problem in either our state
   readout code or our watermark code for this platform.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Our low-level watermark calculation functions don't get called when the
CRTC is disabled or the relevant plane is invisible, so they should
never see a zero htotal or zero bpp.  However add some checks to ensure
this is true so that we don't wind up dividing by zero if we make a
mistake elsewhere in the driver (which the atomic watermark series has
revealed we might be).

References: http://lists.freedesktop.org/archives/intel-gfx/2015-October/077370.htmlSigned-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449171462-30763-6-git-send-email-matthew.d.roper@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>