The DDX driver changes its behavior depending on the value it reads
from i915.enable_fbc, so sanitize the value in order to allow it to
know what's going on. It uses this in order to choose the defaults for
the TearFree option. Before this patch, it would read -1 and always
assume that FBC was disabled, so it wouldn't force TearFree.

v2: Extract intel_sanitize_fbc_option() (Chris).
v3: Rebase.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460574069-14005-1-git-send-email-paulo.r.zanoni@intel.com

We ignore ORIGIN_GTT because the hardware tracking can recognize GTT
writes and take care of them. We also ignore ORIGIN_FLIP because we
deal with flips without relying on the frontbuffer tracking
infrastructure. On the other hand, a flush is a flush and means we're
good to go, so we need to update busy_bits in order to reflect that,
even if we're not going to do anything else about it.

How to reproduce the bug fixed by this patch:
 - boot SKL up to the desktop environment
 - stop the display manager
 - run any of the igt/kms_frontbuffer_tracking/*fbc*onoff* subtests
 - the tests will fail

The steps above will create the right conditions for us to lose track
of busy_bits. If you, for example, run the full set of FBC tests, the
onoff subtests will succeed.

Also notice that the "bug" is that we'll just keep FBC disabled on
cases where it could be enabled, so it's not something the users can
perceive, it just affects power consumption numbers on properly
configured machines.

Testcase: igt/kms_frontbuffer_tracking/*fbc*onoff* (see above)
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459804638-3588-2-git-send-email-paulo.r.zanoni@intel.com

>From https://bugs.freedesktop.org/show_bug.cgi?id=96461 :

This was kind of a difficult bug to track down. If you're using a
Haswell system running GNOME and you have fbc completely enabled and
working, playing videos can result in video artifacts. Steps to
reproduce:

- Run GNOME
- Ensure FBC is enabled and active
- Download a movie, I used the ogg version of Big Buck Bunny for this
- Run `gst-launch-1.0 filesrc location='some_movie.ogg' ! decodebin !
  glimagesink` in a terminal
- Watch for about over a minute, you'll see small horizontal lines go
  down the screen.

For the time being, disable FBC for Haswell by default.

Stefan Richter reported kernel freezes (no video artifacts) when fbc
is on.  (E3-1245 v3 with HD P4600; openbox and some KDE and LXDE
applications, thread begins at https://lkml.org/lkml/2016/4/26/813).
We also got reports from Steven Honeyman on openbox+roxterm.

v2 (From Paulo):
  - Add extra information to the commit message
  - Add Fixes tag
  - Rebase

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96461
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96464
Fixes: a98ee793 ("drm/i915/fbc: enable FBC by default on HSW and BDW")
Cc: stable@vger.kernel.org
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NLyude <cpaul@redhat.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465487895-7401-1-git-send-email-cpaul@redhat.com

The patch was reverted as part of the original nonblocking commit
support, but is required for any kind of nonblocking commit.

This is required to let fbc updates run async. It has a lot of
checks whether certain locks are taken, which can be removed when
the relevant states are passed in as pointers.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-17-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/28208c38-8738-abdf-0cce-8d8f266b9c28@linux.intel.com

Mostly this is unexpected indents. But really it's just a
demonstration for my patch, all these issues have been found&fixed
using the correct source file and line number support I just added.
All line numbers have been perfectly accurate.

One issue looked a bit fishy in intel_lrc.c, where I don't quite grok
what sphinx is unhappy about. But since that file looks like it has
never seen a proper kernel-doc parser I figured better to fix in a
separate path.

v2: Use fancy new &drm_device->struct_mutex linking (Jani).

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This reverts the following patches:

d55dbd06 drm/i915: Allow nonblocking update of pageflips.
15c86bdb drm/i915: Check for unpin correctness.
95c2ccdc Reapply "drm/i915: Avoid stalling on pending flips for legacy cursor updates"
a6747b73 drm/i915: Make unpin async.
03f476e1 drm/i915: Prepare connectors for nonblocking checks.
2099deff drm/i915: Pass atomic states to fbc update functions.
ee7171af drm/i915: Remove reset_counter from intel_crtc.
2ee004f7 drm/i915: Remove queue_flip pointer.
b8d2afae drm/i915: Remove use_mmio_flip kernel parameter.
8dd634d9 drm/i915: Remove cs based page flip support.
143f73b3 drm/i915: Rework intel_crtc_page_flip to be almost atomic, v3.
84fc494b drm/i915: Add the exclusive fence to plane_state.
6885843a drm/i915: Convert flip_work to a list.
aa420ddd drm/i915: Allow mmio updates on all platforms, v2.
afee4d87 Revert "drm/i915: Avoid stalling on pending flips for legacy cursor updates"

"drm/i915: Allow nonblocking update of pageflips" should have been
split up, misses a proper commit message and seems to cause issues in
the legacy page_flip path as demonstrated by kms_flip.

"drm/i915: Make unpin async" doesn't handle the unthrottled cursor
updates correctly, leading to an apparent pin count leak. This is
caught by the WARN_ON in i915_gem_object_do_pin which screams if we
have more than DRM_I915_GEM_OBJECT_MAX_PIN_COUNT pins.

Unfortuantely we can't just revert these two because this patch series
came with a built-in bisect breakage in the form of temporarily
removing the unthrottled cursor update hack for legacy cursor ioctl.
Therefore there's no other option than to revert the entire pile :(

There's one tiny conflict in intel_drv.h due to other patches, nothing
serious.

Normally I'd wait a bit longer with doing a maintainer revert, but
since the minimal set of patches we need to revert (due to the bisect
breakage) is so big, time is running out fast. And very soon
(especially after a few attempts at fixing issues) it'll be really
hard to revert things cleanly.

Lessons learned:
- Not a good idea to rush the review (done by someone fairly new to
  the area) and not make sure domain experts had a chance to read it.

- Patches should be properly split up. I only looked at the two
  patches that should be reverted in detail, but both look like the
  mix up different things in one patch.

- Patches really should have proper commit messages. Especially when
  doing more than one thing, and especially when touching critical and
  tricky core code.

- Building a patch series and r-b stamping it when it has a built-in
  bisect breakage is not a good idea.

- I also think we need to stop building up technical debt by
  postponing atomic igt testcases even longer. I think it's clear that
  there's enough corner cases in this beast that we really need to
  have the testcases _before_ the next step lands.

(cherry picked from commit 5a21b665
from drm-intel-next-queeud)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This reverts the following patches:

d55dbd06 drm/i915: Allow nonblocking update of pageflips.
15c86bdb drm/i915: Check for unpin correctness.
95c2ccdc Reapply "drm/i915: Avoid stalling on pending flips for legacy cursor updates"
a6747b73 drm/i915: Make unpin async.
03f476e1 drm/i915: Prepare connectors for nonblocking checks.
2099deff drm/i915: Pass atomic states to fbc update functions.
ee7171af drm/i915: Remove reset_counter from intel_crtc.
2ee004f7 drm/i915: Remove queue_flip pointer.
b8d2afae drm/i915: Remove use_mmio_flip kernel parameter.
8dd634d9 drm/i915: Remove cs based page flip support.
143f73b3 drm/i915: Rework intel_crtc_page_flip to be almost atomic, v3.
84fc494b drm/i915: Add the exclusive fence to plane_state.
6885843a drm/i915: Convert flip_work to a list.
aa420ddd drm/i915: Allow mmio updates on all platforms, v2.
afee4d87 Revert "drm/i915: Avoid stalling on pending flips for legacy cursor updates"

"drm/i915: Allow nonblocking update of pageflips" should have been
split up, misses a proper commit message and seems to cause issues in
the legacy page_flip path as demonstrated by kms_flip.

"drm/i915: Make unpin async" doesn't handle the unthrottled cursor
updates correctly, leading to an apparent pin count leak. This is
caught by the WARN_ON in i915_gem_object_do_pin which screams if we
have more than DRM_I915_GEM_OBJECT_MAX_PIN_COUNT pins.

Unfortuantely we can't just revert these two because this patch series
came with a built-in bisect breakage in the form of temporarily
removing the unthrottled cursor update hack for legacy cursor ioctl.
Therefore there's no other option than to revert the entire pile :(

There's one tiny conflict in intel_drv.h due to other patches, nothing
serious.

Normally I'd wait a bit longer with doing a maintainer revert, but
since the minimal set of patches we need to revert (due to the bisect
breakage) is so big, time is running out fast. And very soon
(especially after a few attempts at fixing issues) it'll be really
hard to revert things cleanly.

Lessons learned:
- Not a good idea to rush the review (done by someone fairly new to
  the area) and not make sure domain experts had a chance to read it.

- Patches should be properly split up. I only looked at the two
  patches that should be reverted in detail, but both look like the
  mix up different things in one patch.

- Patches really should have proper commit messages. Especially when
  doing more than one thing, and especially when touching critical and
  tricky core code.

- Building a patch series and r-b stamping it when it has a built-in
  bisect breakage is not a good idea.

- I also think we need to stop building up technical debt by
  postponing atomic igt testcases even longer. I think it's clear that
  there's enough corner cases in this beast that we really need to
  have the testcases _before_ the next step lands.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This is required to let fbc updates run async. It has a lot of
checks whether certain locks are taken, which can be removed when
the relevant states are passed in as pointers.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-17-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>

To be used for more efficient Gen range checking.

v2: Remove spurious chunk. (Chris Wilson)
v3: Rebase.
v4: Renamed from INTEL_GEN_RANGE and added GEN_FOREVER.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462874228-6601-1-git-send-email-tvrtko.ursulin@linux.intel.com

   text	   data	    bss	    dec	    hex	filename
6309351	3578714	 696320	10584385	 a18141	vmlinux
6308391	3578714	 696320	10583425	 a17d81	vmlinux

Almost 1KiB of code reduction.

v2: More s/INTEL_INFO()->gen/INTEL_GEN()/ and IS_GENx() conversions

   text	   data	    bss	    dec	    hex	filename
6304579	3578778	 696320	10579677	 a16edd	vmlinux
6303427	3578778	 696320	10578525	 a16a5d	vmlinux

Now over 1KiB!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462545621-30125-3-git-send-email-chris@chris-wilson.co.uk

Refer to the GGTT VM consistently as "ggtt->base" instead of just "ggtt",
"vm" or indirectly through other variables like "dev_priv->ggtt.base"
to avoid confusion with the i915_ggtt object itself and PPGTT VMs.

Refer to the GGTT as "ggtt" instead of indirectly through chaining.

As a bonus gets rid of the long-standing i915_obj_to_ggtt vs.
i915_gem_obj_to_ggtt conflict, due to removal of i915_obj_to_ggtt!

v2:
- Added some more after grepping sources with Chris

v3:
- Refer to GGTT VM through ggtt->base consistently instead of ggtt_vm
  (Chris)

v4:
- Convert all dev_priv->ggtt->foo accesses to ggtt->foo.

v5:
- Make patch checker happy

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Refer to Global GTT consistently as GGTT, thus rename dev_priv->gtt
to dev_priv->ggtt and struct i915_gtt to struct i915_ggtt.

Fix a couple of whitespace problems while at it.

v2:
- Fix a typo in commit message.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

These platforms should be fine now.

FBC can allow very significant power savings for screen-on idle
systems, but it is worth mentioning that a lot of people won't get
significant power savings by enabling this feature because they may
have something else preventing the system from getting into the
deepest sleep states. Examples may include a hungry wifi device or a
max_performance SATA link power management policy. You can check your
PC state residencies on the powertop "Idle stats" tab. I recommend
trying to run "sudo powertop --auto-tune" and then seeing if the
residencies improve.

Oh, and in case you - the person reading this commit message - found
this commit through git bisect, please do the following:
 - Check your dmesg and see if there are error messages mentioning
   underruns around the time your problem started happening.
 - Download intel-gpu-tools, compile it, and run:
   $ sudo ./tests/kms_frontbuffer_tracking --run-subtest '*fbc-*' 2>&1 | tee fbc.txt
   Then send us the fbc.txt file, especially if you get a failure.
   This will really maximize your chances of getting the bug fixed
   quickly.
 - Try to find a reliable way to reproduce the problem, and tell us.
 - Boot with drm.debug=0xe, reproduce the problem, then send us the
   dmesg file.

v2: Don't enable by default on SKL.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455655643-2535-1-git-send-email-paulo.r.zanoni@intel.com

Now that we have top-level gen-independent hw_activate and
hw_deactivate functions, set fbc->active directly from them, removing
the duplicated code.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1454101060-23198-3-git-send-email-paulo.r.zanoni@intel.com

The recent introduction of a new caller of dev_priv->fbc.deactivate()
is a good example of why we need unexport those functions. Anything
outside intel_fbc.c should only call the functions exported by
intel_fbc.c, so in order to enforce that, kill the function pointers
stored inside dev_priv->fbc and replace them with functions that can't
be called from outside intel_fbc.c.

This should make it much harder for new code to call these functions
from outside intel_fbc.c.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1454101060-23198-2-git-send-email-paulo.r.zanoni@intel.com

The FBC fixes we've been doing in the last months required a lot of
refactor, so functions that were once big and called from different
spots are now small and called only once. IMHO now it's better to just
move the contents of these functions to their only callers since this
reduces the number of indirections while reading the code.

While at it, also improve the related comments a little bit.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-26-git-send-email-paulo.r.zanoni@intel.com

We already make sure we run intel_fbc_update_update during modesets
and page flips, and this function takes care of deactivating FBC, so
it shouldn't be possible for us to reach the condition we check at
intel_fbc_work_fn. So instead of grabbing framebuffer references and
adding a lot of code to track when we need to free them, just don't
track anything at all since we shouldn't need to.

v2: Rebase.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-25-git-send-email-paulo.r.zanoni@intel.com

We don't actually use fb_id anywhere. We already compare all
parameters that matter to the hardware: pixel format, stride,
fence_reg and ggtt_offset. The ID shouldn't make a difference.

Besides, we already update the FBC data at every modeset/flip, so this
can't change behind our backs.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-23-git-send-email-paulo.r.zanoni@intel.com

Our dmesg messages started being misleading after we converted to the
enable+activate model: we always print "Disabling FBC", even when
we're just deactivating it. So, for example, when I boot my machine
and do "dmesg | grep -i fbc", I see:
  [drm:intel_fbc_enable] Enabling FBC on pipe A
  [drm:set_no_fbc_reason] Disabling FBC: framebuffer not tiled or fenced
but then, if I read the debugfs file, I will see:
  $ sudo cat i915_fbc_status
  FBC enabled
  Compressing: yes
so we can conclude that dmesg is misleading, since FBC is actually
enabled. What happened is that we deactivated FBC due to fbcon not
being tiled, but when we silently reactivated it when the display
manager started. We don't print activation messages since there may be
way too many of these operations per second during normal desktop
usage.

One possible solution would be to change set_no_fbc_reason to
correctly differentiate between disable and deactivation, but we
removed support from printing activation/deactivation messages in the
past because they were too frequent. So instead of doing this, let's
just not print anything on dmesg, and leave the debugfs file if the
user needs to investigate something. We already print when we enable
and disable FBC anyway on a given pipe, so this should already help
triaging bugs.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-22-git-send-email-paulo.r.zanoni@intel.com

During FBC invalidation, don't call intel_fbc_deactivate if it's not
enabled. This doesn't fix any bug, but helps making the interface
saner.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-21-git-send-email-paulo.r.zanoni@intel.com

Move intel_fbc_enable to a place where it is called regardless of the
"modeset" variable, and make sure intel_fbc_enable can be called
multiple times without intel_fbc_disable being called.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-20-git-send-email-paulo.r.zanoni@intel.com

Instead of duplicating the calls for every platform, let's just put
them in the correct places inside intel_atomic_commit. This will also
make it easier for us to move the enable call in order to support
fasbtoot.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-19-git-send-email-paulo.r.zanoni@intel.com

This opens the possibility of implementing nicer schemes to choose the
CRTC, such as checking the amount of stolen memory available, or
choosing the best pipe on platforms that don't die FBC to pipe or
plane A.

This code was written for another refactor that I ended up discarding,
so I don't actually need it, but I figured this patch would be an
improvement on its own so I kept it on the series.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-18-git-send-email-paulo.r.zanoni@intel.com

Older FBC platforms have this restriction where FBC can't be enabled
if multiple pipes are enabled. In the current code, we disable FBC
before the second pipe becomes visible.

One of the problems with this code is that the current
multiple_pipes_ok() implementation just iterates through all CRTCs
looking at their states, but it doesn't make sure that the state
locks are grabbed. It also can't just grab the locks for every CRTC
since this would kill one of the biggest advantages of atomic
modesetting.

After the recent FBC changes, we now have the appropriate locks for
the given CRTC, so we can just try to maintain the state of each CRTC
and update it once intel_fbc_pre_update is called.

As a last note, I don't have gen 2/3 machines to test this code. My
current plan is to enable FBC on just the newer platforms, so this
patch is just an attempt to get the gen 2/3 code at least looking
sane, so if one day someone decide to fix FBC on these platforms, they
may have less work to do.

Not-tested-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (only on HSW+)
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-16-git-send-email-paulo.r.zanoni@intel.com

Just to be sure nothing will survive a module unload. We need to do
this after the unlock in order to make sure the function won't get
stuck trying to grab the lock we already own while we wait for it to
finish.
Reported-by: NReported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-15-git-send-email-paulo.r.zanoni@intel.com

Instead of:
 - intel_fbc_disable_crtc(crtc)
 - intel_fbc_disable(dev_priv)
we now have:
 - intel_fbc_disable(crtc)
 - intel_fbc_global_disable(dev_priv)

This is because all the other functions that take a CRTC are called
 - intel_fbc_something(crtc)
Instead of:
 - intel_fbc_something_crtc(crtc)

And I also hope that the word "global" is going to help make it more
explicit that "global" is the unusual case, not the opposite.
Reported-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-14-git-send-email-paulo.r.zanoni@intel.com

With the addition and usage of intel_fbc_pre_update,
intel_fbc_deactivate is not used anymore outside intel_fbc.c, so kill
the exported function and rename __intel_fbc_deactivate.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-13-git-send-email-paulo.r.zanoni@intel.com

We'll now call intel_fbc_pre_update instead of intel_fbc_deactivate
during atomic commits. This will continue to guarantee that we
deactivate FBC and it will also update the state checking structures
at the correct time. Then, later, at the point where we were calling
intel_fbc_update, we'll only need to call intel_fbc_post_update.

Also add the proper warnings in case we don't have the appropriate
locks. Daniel mentioned the warnings will have to be removed for async
commits, but let's keep them here while we can.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-12-git-send-email-paulo.r.zanoni@intel.com

So now pre_update will be responsible for unconditionally deactivating
FBC and updating the state cache, while post_update will be
responsible for checking if it can be enabled, then enabling it.

This is one more step into proper locking.

Notice that intel_fbc_flush now calls post_update directly. The FBC
flush can only happen for drawing operations - since we explicitly
ignore the flips -, so the FBC state is not expected to have changed
at this point. With this we can just run post_update, which will make
sure we won't deactivate+reactivate FBC as would be the case now if we
called pre_update + post_update.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-11-git-send-email-paulo.r.zanoni@intel.com

Per the new atomic locking rules, we need to cache the CRTC, plane and
FB state structures we use so we can access them later without needing
more locks. So do this.

Notice that there are some pieces of the FBC code that look at things
that are only computed during the modeset, so we can't just can't
precompute whether FBC can be activated during the update_state_cache
stage. We may be able to do this later.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-10-git-send-email-paulo.r.zanoni@intel.com

If frontbuffer_bits doesn't match the current frontbuffer, there's no
reason to recompress or update FBC.

There was a plan to make the FBC test suite catch this type of
problem, but it never got implemented due to being low priority.

While at it, also implement Ville's suggestion and use
plane->frontbuffer_bit instead of INTEL_FRONTBUFFER_PRIMARY.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-8-git-send-email-paulo.r.zanoni@intel.com

Before this patch, page flips would call intel_frontbuffer_flip() and
intel_frontbuffer_flip_complete(), which would call intel_fbc_flush(),
which would call intel_fbc_update(). The problem is that drawing
operations also trigger intel_fbc_flush() calls, so it's not
guaranteed that we have the CRTC and FB locks grabbed when
intel_fbc_flush() happens, since the call trace may come from the
rendering path.

We're trying to make the FBC code grab the appropriate CRTC/FB locks,
so split the drawing and the flipping logic in order to achieve that
in later patches. So now the frontbuffer tracking code is just going
to be used for frontbuffer drawing, and intel_fbc_update() is going to
be used directly for actual page flips.

As a note, we don't need to call intel_fbc_flip() during the two
places where we call intel_frontbuffer_flip() since in one of them we
already have an intel_fbc_update() call, and in the other we have the
planes disabled.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-7-git-send-email-paulo.r.zanoni@intel.com

We say "dev_priv->fbc.something" way too many times in our code while
we could be saying just "fbc->something" with a previous declaration
of fbc. This has been bothering me for a while but I didn't want to
patch it since I wanted to fix the real problems first. But as I add
more code I keep thinking about it, especially since it makes the code
easier to read and it can make us fit 80 columns easier, so let's just
do the change now.

While at it, also rename from i915_fbc to intel_fbc because the whole
FBC code uses intel_fbc.

v2: Rebase after the work_fn changes.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453406763-10400-1-git-send-email-paulo.r.zanoni@intel.com

The early return inside __intel_fbc_update does not completely check
all the parameters that affect the FBC register values. For example,
we currently lack looking at crtc->adjusted_y (for the fence Y offset)
and all the parameters that affect the CFB size (for i8xx).

Instead of just adding the missing parameters to the check and hoping
that any changes to the fbc_activate functions also come with a
matching change to the __intel_fbc_update check, introduce a new
structure where we store these parameters and use the structure at the
fbc_activate function. Of course, it's still possible to access
everything from dev_priv in those functions, but IMHO the new code
will be harder to break.

v2: Rebase.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-5-git-send-email-paulo.r.zanoni@intel.com

Make our enable/activate checking model more explicit, especially
since we now have intel_fbc_can_activate().
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-4-git-send-email-paulo.r.zanoni@intel.com

Extract all the code that checks if the FBC configuration is valid to
its own function, making __intel_fbc_update() much simpler.
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-3-git-send-email-paulo.r.zanoni@intel.com

Instead of waiting for 50ms, just wait until the next vblank, since
it's the minimum requirement. The whole infrastructure of FBC is based
on vblanks, so waiting for X vblanks instead of X milliseconds sounds
like the correct way to go. Besides, 50ms may be less than a vblank on
super slow modes that may or may not exist.

There are some small improvements in PC state residency (due to the
fact that we're now using 16ms for the common modes instead of 50ms),
but the biggest advantage is still the correctness of being
vblank-based instead of time-based.

v2:
  - Rebase after changing the patch order.
  - Update the commit message.
v3:
  - Fix bogus vblank_get() instead of vblank_count() (Ville).
  - Don't forget to call drm_crtc_vblank_{get,put} (Chris, Ville)
  - Adjust the performance details on the commit message.
v4:
  - Don't grab the FBC mutex just to grab the vblank (Maarten)
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453406585-10233-1-git-send-email-paulo.r.zanoni@intel.com

There's no need to stop and restart FBC, which is quite expensive as
we have to revalidate the CRTC state. After flushing a drawing
operation we know the CRTC state hasn't changed, so a nuke
(recompress) should be fine.

v2: Make it simpler (Chris).
v3: Rewrite the patch again due to patch order changes.
v4: Rewrite commit message (Chris).
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/

When running Cinnamon I see way too many pairs of these messages: many
per second. Get rid of them as they're just telling us FBC is working
as expected. We already have the messages for enable/disable, so we
don't really need messages for activation/deactivation.

v2: Rebase after changing the patch order.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/

Directly call intel_fbc_calculate_cfb_size() in the only place that
actually needs it, and use the proper check before removing the stolen
node. IMHO, this change makes our code easier to understand.

v2: Use drm_mm_node_allocated() (Chris).
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/