Due to DDB overlaps the pipe enabling sequence is not always crescent.
As the previous patch selects the smallest pipe/transcoder in the MST
stream to be master and it needs to be enabled first, this changes
were needed to guarantee that.

So first lets enable all pipes that do not need a fullmodeset as
those don't have any external dependency and those are the ones that
can overlap with each other.

Then on the second loop it will enable all the pipes that needs a
modeset and don't depends on other pipes like MST master
pipe/transcoder.

Then finally all the pipes that needs a modeset and have dependency
on other pipes, that at this point are alread enabled.

v3: rebased

v4:
- added check for modeset_pipes too to decide if is necessary for a
wait a vblank
- added DDB allocation overlap check for pipes that needs a modeset

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-3-jose.souza@intel.com

On TGL the blending of all the streams have moved from DDI to
transcoder, so now every transcoder working over the same MST port must
send its stream to a master transcoder and master will send to DDI
respecting the time slots.

So here adding all the CRTCs that shares the same MST stream if
needed and computing their state again, it will pick the lowest
pipe/transcoder among the ones in the same stream to be master.

Most of the time skl_commit_modeset_enables() enables pipes in a
crescent order but due DDB overlapping it might not happen, this
scenarios will be handled in the next patch.

v2:
- Using recently added intel_crtc_state_reset() to set
mst_master_transcoder to invalid transcoder for all non gen12 & MST
code paths
- Setting lowest pipe/transcoder as master, previously it was the
first one but setting a predictable one will help in future MST e
port sync integration
- Moving to intel type as much as we can

v3:
- Now intel_dp_mst_master_trans_compute() returns the MST master transcoder
- Replaced stdbool.h by linux/types.h
- Skip the connector being checked in
intel_dp_mst_atomic_master_trans_check()
- Using pipe instead of transcoder to compute MST master

v4:
- renamed connector_state to conn_state

v5:
- Improved the parameters of intel_dp_mst_master_trans_compute() to
simply code
- Added call drm_atomic_add_affected_planes() in
intel_dp_mst_atomic_master_trans_check() as helper could not do it
for us
- Removed "if (ret)" left over from v3 changes

v6:
- handled ret == I915_MAX_PIPES case in compute

BSpec: 50493
BSpec: 49190
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-2-jose.souza@intel.com

intel_connector_needs_modeset() will be used outside of
intel_display.c in a future patch so it would only be necessary to
remove the state and add the prototype to the header file.

But while at it, I simplified the arguments and moved it to a better
place intel_atomic.c.

No behavior changes intended here.

v3:
- removed digital from exported version of intel_connector_needs_modeset
- rollback connector to drm type

v4:
- Renamed new_connector_state to new_conn_state
- Going back to drm_connector_state in
intel_encoders_update_prepare/complete as we also have
intel_tv_connector_state
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-1-jose.souza@intel.com

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

The only protection for intel_context.gem_cotext is granted by RCU, so
annotate it as a rcu protected pointer and carefully dereference it in
the few occasions we need to use it.

Fixes: 9f3ccd40 ("drm/i915: Drop GEM context as a direct link from i915_request")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222233558.2201901-1-chris@chris-wilson.co.uk

Start introducing a kref on i915_vma in order to protect the vma unbind
(i915_gem_object_unbind) from a parallel destruction (i915_vma_parked).
Later, we will use the refcount to manage all access and turn i915_vma
into a first class container.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Acked-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222210256.2066451-2-chris@chris-wilson.co.uk

Only acquire the various atomic references required to unbind the vma if
we do need to unbind the vma.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222210256.2066451-1-chris@chris-wilson.co.uk

For CCS formats, the current DRM core check for YUV semiplanar formats
doesn't work; use an i915 specific function for that.

v2: Fix checkpatch warnings.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-11-imre.deak@intel.com

Y planes program the offset and stride of the AUX plane, so make sure we
copy the required info for this into their plane state.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-10-imre.deak@intel.com

During framebuffer creation, we pre-compute offsets for 90/270 plane
rotation. However, only Y and Yf modifiers support 90/270 rotation. So,
skip the calculations for other modifiers.

To keep the gem buffer size check still working for tiled planes, factor
out the logic needed for rotation setup and skip only this part for
tiled planes other than Y/Yf.

v2: Add a bounds check WARN for the rotation info array.
v3: Keep the gem buffer size check working for tiled planes.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-9-imre.deak@intel.com

The CCS plane stride must be fixed on TGL, as it's not configurable for
the display. Instead the HW has a hardwired logic to determine it from
the main plane stride. Make sure userspace passes in the correct stride.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-8-imre.deak@intel.com

Gen-12 display decompression operates on Y-tiled compressed main surface.
The CCS is linear and has 4 bits of metadata for each main surface cache
line pair, a size ratio of 1:256. Gen-12 display decompression is
incompatible with buffers compressed by earlier GPUs, so make use of a new
modifier to identify gen-12 compression. Another notable change is that
render decompression is supported on all planes except cursor and on all
pipes. Start by adding render decompression support for [A,X]BGR888 pixel
formats.

v2: Fix checkpatch warnings (Lucas)
v3:
Rebase, disable color clear, styling changes and modify
intel_tile_width_bytes and intel_tile_height to handle linear CCS
v4:
- Use format block descriptors and the i915 specific func to get the
  subsampling for each color plane.
- Use helpers to convert between CCS and main planes.
v5:
- Fix subsampling returned by intel_fb_plane_get_subsampling() for
  the CCS plane of the first plane.
v6:
- Rebased on v2 of patch 4.
v7:
- Fix plane dimensions during FB check.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Nanley G Chery <nanley.g.chery@intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com> (v6)
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-7-imre.deak@intel.com

Gen-12 has a new compression format, add a new modifier to indicate that.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Nanley G Chery <nanley.g.chery@intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-6-imre.deak@intel.com

Using helpers instead of open coding this to select a CCS plane for a
main plane makes the code cleaner and less error-prone when the location
of CCS plane can be different based on the format (packed vs. YUV
semiplanar). The same applies to selecting an AUX plane which can be a
UV plane (for an uncompressed YUV semiplanar format), or a CCS plane.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-5-imre.deak@intel.com

intel_fill_fb_info() has grown quite large and wrapping the offset checks
into a separate function makes the loop a bit easier to follow.

v2: Skip the check for non-CCS planes. (Mika)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-4-imre.deak@intel.com

Easier to read if all the alignment changes are in one place and contained
within a function.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-3-imre.deak@intel.com

intel_tile_dims() computes tile height using size and width, when there
is already a function to do just that - intel_tile_height()

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221120543.22816-2-imre.deak@intel.com

Needs i915_drv.h because i915 gets dereferenced.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219155652.2666-2-jani.nikula@intel.com

Fix the forward declaration.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219155652.2666-1-jani.nikula@intel.com

The power domain covers VDSC for DSI transcoder on ICL, and it's
pedantically about pipe, not transcoder, on TGL.
Reported-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219133845.9333-1-jani.nikula@intel.com

The GT system is becoming more and more a stand-alone system in
i915 and it's fair to assign it its own debugfs directory.

rc6, rps and llc debugfs files are gt related, move them into the
gt debugfs directory.
Signed-off-by: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222144046.1674865-3-chris@chris-wilson.co.uk

Now that we don't need to create GEM contexts in the middle of engine
construction, we can pull the engine init/setup loops together.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222144046.1674865-2-chris@chris-wilson.co.uk

Since intel_gt_resume() is always immediately proceeded by init_hw, pull
the call into intel_gt_resume, where we have the rpm and fw already
held.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222144046.1674865-1-chris@chris-wilson.co.uk

Begin pulling the GT setup underneath a single GT umbrella; let intel_gt
take ownership of its engines! As hinted, the complication is the
lifetime of the probed engine versus the active lifetime of the GT
backends. We need to detect the engine layout early and keep it until
the end so that we can sanitize state on takeover and release.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222120752.1368352-1-chris@chris-wilson.co.uk

As the GEM global context setup is now independent of the GT state
(although GT does currently still depend upon the global
i915->kernel_context), we can move its init earlier, leaving the gt init
ready to be extracted.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221200109.1202310-1-chris@chris-wilson.co.uk

Since we may retire timelines from secondary workers,
intel_gt_retire_requests() is not always a reliable indicator that all
pending retirements are complete. If we do detect secondary workers are
in progress, recommend intel_gt_wait_for_idle() to repeat the retirement
check.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221180204.1201217-1-chris@chris-wilson.co.uk

Allocate only an internal intel_context for the kernel_context, forgoing
a global GEM context for internal use as we only require a separate
address space (for our own protection).

Now having weaned GT from requiring ce->gem_context, we can stop
referencing it entirely. This also means we no longer have to create random
and unnecessary GEM contexts for internal use.

GEM contexts are now entirely for tracking GEM clients, and intel_context
the execution environment on the GPU.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221160324.1073045-1-chris@chris-wilson.co.uk

Enable and cleanup the engine->retire for the mock engine.

Fixes: dc93c9b6 ("drm/i915/gt: Schedule request retirement when signaler idles")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221001136.720154-1-chris@chris-wilson.co.uk

We have several places where we want to allocate a pristine
crtc state. Some of those currently call intel_crtc_state_reset()
to properly initialize all the non-zero defaults in the state, but
some places do not. Let's add intel_crtc_state_alloc() to do both
the alloc and the reset, and call that everywhere we need a fresh
crtc state.

v2: s/kzalloc/kmalloc/ since we memset() anyway (José)

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219111430.17527-1-ville.syrjala@linux.intel.comReviewed-by: José Roberto de Souza <jose.souza@intel.com>

Decide whether or not we need to disable arbitration within user batches
based on our intel_engine_has_preemption() flag.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213151331.1788371-1-chris@chris-wilson.co.uk

Instead of rummaging through the intel_context to peek at the GEM
context in the middle of request submission to decide whether to use
semaphores, store that information on the intel_context itself.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191220101230.256839-2-chris@chris-wilson.co.uk

Keep the intel_context as being the primary state for i915_request, with
the GEM context a backpointer from the low level state for the rarer
cases we need client information. Our goal is to remove such references
to clients from the backend, and leave the HW submission agnostic to
client interfaces and self-contained.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191220101230.256839-1-chris@chris-wilson.co.uk

Since we added the context_alloc callback to intel_context_ops, we can
safely install a custom hook for the deferred virtual context allocation.
This means that all new contexts behave the same upon creation,
simplifying later code.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219232932.189197-1-chris@chris-wilson.co.uk

Avoid adding the retire workers to the virtual engine so that we don't
end up in the unenviable situation of trying to free the virtual engine
while its worker remains active.

Fixes: dc93c9b6 ("drm/i915/gt: Schedule request retirement when signaler idles")
Closes: https://gitlab.freedesktop.org/drm/intel/issues/867Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219221344.161523-1-chris@chris-wilson.co.uk

All the other display related tracepoints use intel_ instead
if i915_ as the prefix. Do the same for the pipe update
tracepoints so I don't always have to spend time looking for
them.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213133453.22152-6-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

I fumbled the conflict resolution a bit when applying the
fbc vblank wait w/a. Because of that we now call intel_fbc_pre_update()
twice. Remove the second redundant call.
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213133453.22152-2-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

icl and tgl are still affected by the modulo 4 PLANE_OFFSET.y
underrun issue. Reject such configurations on all gen9+ platforms.

Can be reproduced easily with the following sequence of
hardware poking:
while {
  write FBC_CTL.enable=1
  wait for vblank

  write PLANE_OFFSET .x=0 .y=32
  write PLANE_SURF
  wait for vblank

  # if PLANE_OFFSET.y is multiple of 4 the underrun won't happen
  write PLANE_OFFSET .x=0 .y=31
  write PLANE_SURF
  wait for vblank

  # extra vblank wait is required here presumably
  # to get FBC into the proper state
  wait for vblank

  write FBC_CTL.enable=0
  # underrun happens some time after FBC disable
  wait for vblank
}

Both 8888 and 565 pixel formats and all tilinga formats
seem affected. Reproduced on KBL/GLK/ICL/TGL. BDW confirmed
not affected.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/792Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213133453.22152-1-ville.syrjala@linux.intel.comReviewed-by: Imre Deak <imre.deak@intel.com>

Currently pointers to and from are not initialized and may contain
garbage values. This will cause uninitialized pointer reads in the
call to intel_frontbuffer_track and later checks to see if to and from
are null.  Fix this by ensuring to and from are initialized to NULL.

Addresses-Coverity: ("Uninitialised pointer read)"
Fixes: da42104f ("drm/i915: Hold reference to intel_frontbuffer as we track activity")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219190916.24693-1-colin.king@canonical.com

When we park RPS, we set the GPU to run at minimum 'idle' frequency.
However, as the GPU is idle, we also disable the worker and RPS
interrupts - changing the RPS thresholds has no effect, it just incurs
extra changes to restore them when we unpark. So on parking, leave the
thresholds set to the current power level and so we expect them to be
valid for our restart.

References: https://gitlab.freedesktop.org/drm/intel/issues/848Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218210545.3975426-2-chris@chris-wilson.co.uk

Use non-forcewaked writes to queue RPS register changes that will take
effect when the write buffer is flushed, rather than wake the mmio
device for immediate effect. This is so that we can avoid a slow
forcewake dance upon unparking, and at our irregular updates.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218210545.3975426-1-chris@chris-wilson.co.uk