commit 4e0b83a5 ("drm/i915: Extract per-platform plane->check()
functions") removed the plane max stride check for sprite planes.
I was going to add it back when introducing GTT remapping for the
display, but after further thought it seems better to re-introduce
it separately.

So let's add the max stride check back. And let's do it in a nicer
form than what we had before and do it for all plane types (easy
now that we have the ->max_stride() plane vfunc).

Only sprite planes really need this for now since primary planes
are capable of scanning out the current max fb size we allow, and
cursors have more stringent stride checks elsewhere.

Cc: José Roberto de Souza <jose.souza@intel.com>
Fixes: 4e0b83a5 ("drm/i915: Extract per-platform plane->check() functions")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180918140243.12207-1-ville.syrjala@linux.intel.com


Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

From gen11 onwards RGB565 90/270 plane rotation is supported on hardware.

IGT: https://patchwork.freedesktop.org/series/48756/


Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[mlankhorst: Rebase on top of current dinq (self), fix grammar (Ville).]
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1535373473-3594-3-git-send-email-juhapekka.heikkila@gmail.com

Our execlist dispatch code requires a ppGTT so make sure we enforce that
option in intel_sanitize_enable_ppgtt(). The comment already tries to
explain that execlists requires ppgtt, but was written when gen8 may
have also taken the legacy path; so rewrite the code to match the
comment by using HAS_EXECLISTS() feature instead of the gen.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180922141804.21183-1-chris@chris-wilson.co.uk

This cleanup patch makes changes to use for_each_pipe loop
during bit-mask assignment of allowed crtc with encoder.

changes:
 - use BIT(i) macro instead of (1 << i) (Chris)
changes from V2:
 - use int for consistency (Jani)
changes from V3:
 - instead use enum pipe (Ville)
changes from V4:
 - drop DP/HDMI changes, as already part of patch from ville

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180919083126.31805-1-mahesh1.kumar@intel.com

In the sequence

<0>[  531.960431] drv_self-4806    7.... 527402570us : intel_gpu_reset: engine_mask=1, ret=0, retry=0
<0>[  531.960431] drv_self-4806    7.... 527402571us : execlists_reset: rcs0 request global=115de, current=71133
<0>[  531.960431] drv_self-4806    7d..1 527402571us : execlists_cancel_port_requests: rcs0:port0 global=71134 (fence 826b:198), (current 71133)
<0>[  531.960431] drv_self-4806    7d..1 527402572us : execlists_cancel_port_requests: rcs0:port1 global=71135 (fence 826c:53), (current 71133)
<0>[  531.960431] drv_self-4806    7d..1 527402572us : __i915_request_unsubmit: rcs0 fence 826c:53 <- global=71135, current 71133
<0>[  531.960431] drv_self-4806    7d..1 527402579us : __i915_request_unsubmit: rcs0 fence 826b:198 <- global=71134, current 71133
<0>[  531.960431] drv_self-4806    7.... 527402613us : intel_engine_cancel_stop_cs: rcs0
<0>[  531.960431] drv_self-4806    7.... 527402624us : execlists_reset_finish: rcs0

we are missing the execlists_submission_tasklet() invocation before the
execlists_reset_fini() implying that either the queue is empty, or we
failed to schedule and run the tasklet on finish. Add an assert so we
are sure that on unsubmitting the incomplete request after reset, the
queue is indeed populated.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180919195544.1511-12-chris@chris-wilson.co.uk

This patch programs the time (in escape clocks) to drive
the link in the initialization (i.e. LP-11) state.

v2: Rebase
v3: Remove step hard coding comments (Jani N)

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1537095223-5184-5-git-send-email-madhav.chauhan@intel.com

This patch enables DDI buffer by writing to DDI_BUF_CTL
register and wait for DDI status to be *not idle* for a
port.

v2: Rebase
v3: Remove step hard coding comments (Jani N)

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1537095223-5184-4-git-send-email-madhav.chauhan@intel.com

This patch setup voltage swing before enabling
combo PHY DDI (shared with DSI).
Note that DSI voltage swing programming is for
high speed data buffers. HW automatically handles
the voltage swing for the low power data buffers.

v2: Rebase
v3: Address various review comments related to VSWING
    programming (Jani N)

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1537095223-5184-3-git-send-email-madhav.chauhan@intel.com

This patch set the loadgen select and latency optimization for
aux and transmit lanes of combo phy transmitters. It will be
used for MIPI DSI HS operations.

v2: Rebase
v3: Add empty line to make code more legible (Ville).

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1537095223-5184-2-git-send-email-madhav.chauhan@intel.com

We can't make NV12 work any other way. The scaler doesn't handle odd
coordinates well, and we will get visual corruption on the screen.

Changes since v1:
- Put the check in intel_plane_check_src_coordinates. (Ville)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-9-maarten.lankhorst@linux.intel.com

This cleans the code up slightly, and will make other changes easier.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-8-maarten.lankhorst@linux.intel.com

On skylake we can switch to a high quality scaler mode when only 1 out
of 2 scalers are used, but on GLK and later bit 28 has a different
meaning. Don't set it, and make clear the distinction between
SKL and later PS values.

Changes since v1:
- Add missing break statement.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
[mlankhorst: Remove extra newline]
Link: https://patchwork.freedesktop.org/patch/msgid/20180921144437.20037-1-maarten.lankhorst@linux.intel.com

drm_atomic_helper_commit_planes_on_crtc calls begin_commit,
then plane_update hooks, then flush_commit. Because we keep our own
visibility tracking through plane_state->visible there's no need to
rely on the atomic hooks for this.

By explicitly writing our own helper, we can update visible planes
as needed, which is useful to make NV12 support work as intended.

Changes since v1:
- Reword commit message. (Matt Roper)
- Rename to intel_update_planes_on_crtc(). (Matt)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-6-maarten.lankhorst@linux.intel.com

This will only disable planes we actually had marked as visible in
crtc_state->visible_planes and cleans up intel_crtc_disable_plane()
slightly.

This is also useful for when we start enabling NV12 support for gen11,
in which we will make the separate Y plane visible, but ignore the
Y plane's state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-5-maarten.lankhorst@linux.intel.com

We need to assume the plane has been visible before, even if no CRTC
is assigned to the plane. This is because when enabling a nv12 plane
on gen11, we will have to enable an extra plane and make it visible
by marking it in crtc_state->active_planes for
intel_update_planes_on_crtc().

Additionally, clear visible flag in intel_plane_atomic_check, in case
we ever hit a bug with visibility. Our code implicitly assumes that
plane_state->visible is only true when crtc and fb are set,
so we will either null deref in intel_fbc_choose_crtc() or
do something bad during the actual commit which cares even more.

Changes since v1:
- Unconditionally clear crtc_state->active_planes as well.
- Reword commit message, since this is now a preparation patch for
  NV12 Y / UV plane linking.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[mlankhorst: Clear nv12_planes in the beginning as well, clarify commit message]
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-4-maarten.lankhorst@linux.intel.com

While we may not update new_crtc_state, we may clear active_planes
if the new cursor update state will disable the cursor, but we fail
after. If this is immediately followed by a modeset disable, we may
soon not disable the planes correctly when we start depending on
active_planes.

Changes since v1:
- Clarify why we cannot swap crtc_state. (Matt)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-3-maarten.lankhorst@linux.intel.com

Use old/new_intel_crtc_state, and get rid of all the conversion casts
where they don't add anything.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920102711.4184-2-maarten.lankhorst@linux.intel.com

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Fix up the error unwind for logical_ring_init() failing by moving the
cleanup into the callers who own the various bits of state during
initialisation, so we don't forget to free the state allocated by the
caller.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920195948.16448-1-chris@chris-wilson.co.uk

Once we have flushed the first request through the system to both load a
context and record the default state; tell the GPU to park and idle
itself, putting itself immediately (hopefully at least) into a
powersaving state, and allowing ourselves to start from known state
after setting up all our bookkeeping.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920161343.1117-1-chris@chris-wilson.co.uk

As we emit requests or touch HW directly for some of the live tests, the
requirement is that we hold the rpm wakeref before doing so. We want a
mix of granularity since we will want to test runtime suspend, so try to
mark up only the critical sections where we need rpm for the live test.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108002


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920144934.16611-1-chris@chris-wilson.co.uk

It really wants dev_priv anyway, also now matches i915_gem_init_stolen.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@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/20180920142707.19659-2-matthew.auld@intel.com

If we copy all the contents of the sg across and not just the page link,
we can then also put it to work in fake_get_huge_pages and beyond.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920142707.19659-1-matthew.auld@intel.com

Stolen memory is lost across S4 (hibernate) or S3-RST as it is a portion
of ordinary volatile RAM. As we allocate our rings from stolen, this may
include the rings used for our preempt context and their breadcrumb
instructions. In order to allow preemption following hibernation and
loss of stolen memory, we therefore need to repopulate the instructions
inside the lost ring upon resume. To handle both module load and resume,
we simply defer constructing the ring to first use.

Testcase: igt/drv_selftest/live_gem
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180919205432.18394-1-chris@chris-wilson.co.uk

We need to exercise the HW and submission paths for switching contexts
rapidly to check that features such as execlists' wa_tail are adequate.
Plus it's an interesting baseline latency metric.

v2: Check the initial request for allocation errors
v3: Use finite waits for more robust handling of broken code

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180920105809.1872-1-chris@chris-wilson.co.uk

Remember to release the batch bo reference if we hit an error trying to
submit our MI_STORE_DWORD_IMM.

References: https://bugs.freedesktop.org/show_bug.cgi?id=107979


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180919195544.1511-9-chris@chris-wilson.co.uk

PSR requires AUX IO power well to be enabled. This was already in place
for CNL, extend this for ICL too. Not enabling the power well results in
the aux error interrupts when the hardware exits PSR.

Reported-by: Casey G Bowman <casey.g.bowman@intel.com>
Reported-by: Jyoti R Yadav <jyoti.r.yadav@intel.com>
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Cc: Jyoti R Yadav <jyoti.r.yadav@intel.com>
Cc: Casey G Bowman <casey.g.bowman@intel.com>
Tested-by: Casey G Bowman <casey.g.bowman@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914001822.2503-1-dhinakaran.pandiyan@intel.com

SDVO encoders can have multiple different types of outputs hanging off
them. Currently the code tries to muck around with various is_foo
flags in the encoder to figure out which type its driving. That doesn't
work with atomic and other stuff, so let's nuke those flags and just
look at which type of connector we're actually dealing with.

The is_hdmi we'll need as that's not discoverable via the output flags,
but we'll just move it under the connector.

We'll also move the sdvo fixed mode handling out from the .get_modes()
hook into the sdvo lvds init function so that we can bail out properly
if there is no fixed mode to be found.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180917151504.8754-1-ville.syrjala@linux.intel.com


Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Smatch reports:
../drivers/gpu/drm/i915/intel_sprite.c:1192 skl_plane_check_fb() warn: was || intended here instead of &&?

Obviously smatch is correct here since we're trying to check if we're
using either of the ccs modifiers. Since we now have is_ccs_modifier()
let's use it to fix this.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: e21c2d33 ("drm/i915: Move skl plane fb related checks into a better place")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180918131059.793-1-ville.syrjala@linux.intel.com


Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Clean up some cases where we're dealing with GTT pages instead of
system pages to use I915_GTT_PAGE_SIZE instead of PAGE_SHIT. So
just replace the the shifts with mul/div as appropriate. These
are the easy ones, the rest probably need some actual thought.

No real changes in the generated asm. Only gen8_ppgtt_insert_4lvl()
was affected as gcc decided to do the following change:
-     be9:       89 d9                   mov    %ebx,%ecx
-     beb:       c1 e1 0c                shl    $0xc,%ecx
-     bee:       48 63 c9                movslq %ecx,%rcx
+     be9:       48 63 cb                movslq %ebx,%rcx
+     bec:       48 c1 e1 0c             shl    $0xc,%rcx
and that then shifted a bunch of the offset by one byte. I presume
the sign extensions in the asm are due to integer promotions from
u16 etc. Hopefully someone has confirmed that those don't end up
doing the wrong thing for us.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180917171414.19220-1-ville.syrjala@linux.intel.com


Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

If we fail to allocate an array for a large number of user requested
capture objects, reduce the array size and try to grab at least some of
the objects!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911115810.8917-3-chris@chris-wilson.co.uk

The prior assumption was that we did not need to reset the CSB on
wedging when cancelling the outstanding requests as it would be cleaned
up in the subsequent reset prior to restarting the GPU. However, what
was not accounted for was that in preparing for the reset, we would try
to process the outstanding CSB entries. If the GPU happened to complete
a CS event just as we were performing the cancellation of requests, that
event would be kept in the CSB until the reset -- but our bookkeeping
was cleared, causing confusion when trying to complete the CS event.

v2: Use a sanitize on unwedge to avoid interfering with eio suspend
(where we intentionally disable GPU reset).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107925


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914080017.30308-3-chris@chris-wilson.co.uk

If an asynchronous wait on a foriegn fence, we print a warning
indicating which fence was not signaled. As i915_sw_fences become more
common, include the debug hint (the symbol-name of the target) to help
identify the waiter. E.g.

[   31.968144] Asynchronous wait on fence sw_sync:gem_eio:1 timed out (hint:submit_notify [i915])

We also want to downgrade from a warning to a notice (normal but
significant condition) as the timeout is imposed and controlled by the
caller (i.e. it is deliberate) and can be provoked by userspace.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914124007.18790-1-chris@chris-wilson.co.uk

That we use a WB mapping for updating the RING_TAIL register inside the
context image even on !llc machines has been a source of consternation
for every reader. It appears to work on bsw+, but it may just have been
that we have been incredibly bad at detecting the errors.

v2: With extra enthusiasm.
v3: Drop force of map type for pinned default_state as by the time we
pin it, the map type is always WB and doesn't conflict with the earlier
use by ce->state.
v4: Transfer engine->default_state from MAP_WC to MAP_WB on creation so
we do not need the MAP_FORCE littered around the backends

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-3-chris@chris-wilson.co.uk

Check we can indeed acquire a WB mapping of the context image on module
load. Later this will give us the opportunity to validate that we can
switch from WC to WB as required.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-2-chris@chris-wilson.co.uk

Now that we reload both RING_HEAD and RING_TAIL when rebinding the
context, we do not need to scrub those registers immediately on resume.

v2: Handle the perma-pinned contexts.
v3: Set RING_TAIL on context-pin so that we always have known state in
the context image for the ring registers and all parties have similar
code (ripe for refactoring).

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/20180914123504.2062-1-chris@chris-wilson.co.uk

In order to reduce latency when checking for idle we kick the tasklet
directly. Sometimes this is not enough as it is queued on another cpu
and so to improve the accuracy of this idle-check (and so to reduce
latency overall by avoiding another pass, or worse declaring a timeout!)
wait for the tasklet to complete.

References: https://bugs.freedesktop.org/show_bug.cgi?id=107916


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>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914080017.30308-2-chris@chris-wilson.co.uk

If we try and fail to allocate a i915_request, we apply some
backpressure on the clients to throttle the memory allocations coming
from i915.ko. Currently, we wait until completely idle, but this is far
too heavy and leads to some situations where the only escape is to
declare a client hung and reset the GPU. The intent is to only ratelimit
the allocation requests and to allow ourselves to recycle requests and
memory from any long queues built up by a client hog.

Although the system memory is inherently a global resources, we don't
want to overly penalize an unlucky client to pay the price of reaping a
hog. To reduce the influence of one client on another, we can instead of
waiting for the entire GPU to idle, impose a barrier on the local client.
(One end goal for request allocation is for scalability to many
concurrent allocators; simultaneous execbufs.)

To prevent ourselves from getting caught out by long running requests
(requests that may never finish without userspace intervention, whom we
are blocking) we need to impose a finite timeout, ideally shorter than
hangcheck. A long time ago Paul McKenney suggested that RCU users should
ratelimit themselves using judicious use of cond_synchronize_rcu(). This
gives us the opportunity to reduce our indefinite wait for the GPU to
idle to a wait for the RCU grace period of the previous allocation along
this timeline to expire, satisfying both the local and finite properties
we desire for our ratelimiting.

There are still a few global steps (reclaim not least amongst those!)
when we exhaust the immediate slab pool, at least now the wait is itself
decoupled from struct_mutex for our glorious highly parallel future!

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106680


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914080017.30308-1-chris@chris-wilson.co.uk

For finding the panel fitter and PLL for a particular modeset is a part
of that modeset and should be included with the reset of the
DRM_DEBUG_KMS.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180913131629.3978-1-chris@chris-wilson.co.uk