Factor out the combo PHY lane power configuration code to a separate
helper; it will be also needed by the next patch adding the same
configuration for DDI ports.
Add support for DDI ports and lane reversal as preparation for the next
patch.
The PWR_DOWN_LN_1 value is unspecified in the BSpec register description
so remove it.
v2:
- Fix up the wrong assumption that the encodings are the same for DDI
and DSI ports. (Jani)
v3:
- Use intel_ instead of icl_ prefix. (Jani)
- Add required headers to intel_combo_phy.h after the upstream header
refactoring.
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Madhav Chauhan <madhav.chauhan@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com> (v2)
Link: https://patchwork.freedesktop.org/patch/msgid/20190425185253.3197-1-imre.deak@intel.com
s/pipe/transcoder/ when dealing with hsw+ audio registers. This
won't actually make any real difference since there is no audio
on the EDP transcoder. But this should avoid a bit of confusion
when cross checking against the spec.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190430142901.7302-2-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
We've already committed to enabling audio when intel_audio_codec_enable()
is called. We can't back out even if the ELD has turned sour in the
meantime. So just spew some debug log and plow ahead. Otherwise the
state checker gets unhappy when audio isn't enabled when it is
expected to be.
I suppose we really ought to precompute the ELD as well, but
let's just toss in a FIXME for the future.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103841
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190430142901.7302-1-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Currently due to regression CI machine displays show corrupt picture.
Problem is when CDCLK is as low as 79200, picture gets unstable, while
DSI and DE pll values were confirmed to be correct. Limiting to 158400
as agreed with Ville.
We could not come up with any better solution yet, as PLL divider values
both for MIPI(DSI PLL) and CDCLK(DE PLL) are correct, however seems that
due to some boundary conditions, when clocking is too low we get wrong
timings for DSI display. Similar workaround exists for VLV though, so
just took similar condition into use. At least that way GLK platform
will start to be usable again, with current drm-tip.
v2: Fixed commit subject as suggested.
v3: Added generic bugs(crc failures, screen not init
for GLK DSI which might be affected).
v4: Added references tag for bugs affected.
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=109267
References: https://bugs.freedesktop.org/show_bug.cgi?id=103184
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190430125119.7478-1-stanislav.lisovskiy@intel.com
The workqueue code complains viciously if we try to queue more work onto
the queue while attampting to drain it. As we asynchronously free
objects and defer their enqueuing with RCU, it is quite tricky to
quiesce the system before attempting to drain the workqueue. Yet drain
we must to ensure that the worker is idle before unloading the module.
Give the freed object drain 3 whole passes with multiple rcu_barrier()
to give the defer freeing of several levels each protected by RCU and
needing a grace period before its parent can be freed, ultimately
resulting in a GEM object being freed after another RCU period.
A consequence is that it will make module unload even slower.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110550
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190501135753.8711-1-chris@chris-wilson.co.uk
Make the engine responsible for cleaning itself up!
This removes the i915->gt.cleanup vfunc that has been annoying the
casual reader and myself for the last several years, and helps keep a
future patch to add more cleanup tidy.
v2: Assert that engine->destroy is set after the backend starts
allocating its own state.
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/20190501103204.18632-1-chris@chris-wilson.co.uk
The pipe has a special HDR mode with higher precision when only
HDR planes are active. Let's use it.
Curiously this fixes the kms_color gamma/degamma tests when
using a HDR plane, which is always the case unless one hacks
the test to use an SDR plane. If one does hack the test to use
an SDR plane it does pass already.
I have no actual explanation how the output after the gamma
LUT can be different between the two modes. The way the tests
are written should mean that the output should be identical
between the solid color vs. the gradient. But clearly that
somehow doesn't hold true for the HDR planes in non-HDR pipe
mode. Anyways, as long as we stick to one type of plane the
test should produce sensible results now.
v2: s/HDR_MODE/HDR_MODE_PRECISION/ (Shashank)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190412183009.8237-2-ville.syrjala@linux.intel.com
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Tested-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
It used to be handy that we only had a couple of headers, but over time
i915_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/6aea17072684dec0b04b6831c0c0e5a134edf87e.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/87904259868782c1ad664d852b27a50c1597cfaa.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
v2: fix sparse warnings on undeclared global functions
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/20190429125331.32499-1-jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/f35fc2ba76d7dd5886d304ad690a6f9078a56ecd.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/b2fd1b2b968aa0ce010d17e2811bc275cf9ca251.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/76d2719b462004ec6f6f5c302ee5d3876357c599.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/2e4fb1e67ed38870df3040bb0a1b1a58fd90cc86.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/1e2fb90dcce2063b1c464dc64aa8fa6005b62bc6.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
i915_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the header remains self-contained, and do so with minimal further
includes, using forward declarations as needed.
No functional changes.
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/cf9b17d56489e15d82356575037432ad04712475.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
v2: fix sparse warnings on undeclared global functions
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/20190429125011.10876-1-jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/64e46278dc8dccc9c548ef453cb2ceece5367bb2.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/2e5a386cbdcd361399e94c55d47a12352a5216c7.1556540890.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/eb23be64d04957b2cf82b79fd69cc57ed84043a4.1556540889.git.jani.nikula@intel.com
It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.
Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.
No functional changes.
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/0507c5523d1f07a48e6679a04db75246ce8ba766.1556540889.git.jani.nikula@intel.com
Separate the two comments: one is a workaround and the other is a sanity
check. We could just compare != 1, but let's treat them differently due
to having different meaning.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190404230426.15837-4-lucas.demarchi@intel.com
WaEnableStateCacheRedirectToCS context workaround configures the L3 cache
to benefit 3d workloads but media has different requirements.
Remove the workaround and whitelist the register to allow any userspace
configure the behaviour to their liking.
v2:
* Remove the workaround apart from adding the whitelist.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: kevin.ma@intel.com
Cc: xiaogang.li@intel.com
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Acked-by: Anuj Phogat <anuj.phogat@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190418100634.984-1-tvrtko.ursulin@linux.intel.com
Fixes: f63c7b4880 ("drm/i915/icl: WaEnableStateCacheRedirectToCS")
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
[tursulin: Anuj reported no GPU hangs or performance regressions with old
Mesa on patched kernel.]
If the context has not been used yet, it needs no barrier, and in the
process fix up the selftest in mock_contexts.
Testcase: igt/gem_ctx_clone/vm
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/20190429090735.326-1-chris@chris-wilson.co.uk
Having transitioned GEM over to using intel_context as its primary means
of tracking the GEM context and engine combined and using
i915_request_create(), we can move the older i915_request_alloc()
helper function into selftests/ where the remaining users are confined.
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/20190426163336.15906-9-chris@chris-wilson.co.uk
We no longer need to track the active intel_contexts within each engine,
allowing us to drop a tricky mutex_lock from inside unpin (which may
occur inside fs_reclaim).
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/20190426163336.15906-8-chris@chris-wilson.co.uk
We switched to a tree of per-engine HW context to accommodate the
introduction of virtual engines. However, we plan to also support
multiple instances of the same engine within the GEM context, defeating
our use of the engine as a key to looking up the HW context. Just
allocate a logical per-engine instance and always use an index into the
ctx->engines[]. Later on, this ctx->engines[] may be replaced by a user
specified map.
v2: Add for_each_gem_engine() helper to iterator within the engines lock
v3: intel_context_create_request() helper
v4: s/unsigned long/unsigned int/ 4 billion engines is quite enough.
v5: Push iterator locking to caller
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/20190426163336.15906-7-chris@chris-wilson.co.uk
In the next patch, we require the engine vfuncs setup prior to
initialising the pinned kernel contexts, so split the vfunc setup from
the engine initialisation and call it earlier.
v2: s/setup_xcs/setup_common/ for intel_ring_submission_setup()
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/20190426163336.15906-6-chris@chris-wilson.co.uk
Move the intel_context_instance() to the caller so that we can decouple
ourselves from one context instance per engine.
v2: Rename pin_lock() to lock_pinned(), hopefully that is clearer.
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/20190426163336.15906-5-chris@chris-wilson.co.uk
Our eventual goal is to rid request construction of struct_mutex, with
the short term step of lifting the struct_mutex requirements into the
higher levels (i.e. the caller must ensure that the context is already
pinned into the GTT). In this patch, we pin GVT's shadow context upon
allocation and so keep them pinned into the GGTT for as long as the
virtual machine is alive, and so we can use the simpler request
construction path safe in the knowledge that the hard work is already
done.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-1-chris@chris-wilson.co.uk
I like my functions simple, so split up the low level bits from
cherryview_load_luts() into separate functions. Also rename the
whole thing to chv_load_luts() to match the new world order.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190408121815.30142-1-ville.syrjala@linux.intel.com
Reviewed-by: Swati Sharma <swati2.sharma@intel.com>
When I refactored the code into its own function I accidentally
misplaced the <<16 shifts for some of the registers causing us
to lose the blue channel entirely.
We should really find a way to test this...
Cc: Uma Shankar <uma.shankar@intel.com>
Fixes: d2c19b06d6 ("drm/i915: Clean up ilk/icl pipe/output CSC programming")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190425192419.24931-1-ville.syrjala@linux.intel.com
Reviewed-by: Swati Sharma <swati2.sharma@intel.com>
Broadwater and the rest of gen4 do support being able to saving and
reloading context specific registers between contexts, providing isolation
of the basic GPU state (as programmable by userspace). This allows
userspace to assume that the GPU retains their state from one batch to the
next, minimising the amount of state it needs to reload and manually save
across batches.
v2: CONSTANT_BUFFER woes
Running through piglit turned up an interesting issue, a GPU hang inside
the context load. The context image includes the CONSTANT_BUFFER command
that loads an address into a on-gpu buffer, and the context load was
executing that immediately. However, since it was reading from the GTT
there is no guarantee that the GTT retains the same configuration as
when the context was saved, resulting in stray reads and a GPU hang.
Having tried issuing a CONSTANT_BUFFER (to disable the command) from the
ring before saving the context to no avail, we resort to patching out
the instruction inside the context image before loading.
This does impose that gen4 always reissues CONSTANT_BUFFER commands on
each batch, but due to the use of a shared GTT that was and will remain
a requirement.
v3: ECOSKPD to the rescue
Ville found the magic bit in the ECOSKPD to disable saving and restoring
the CONSTANT_BUFFER from the context image, thereby completely avoiding
the GPU hangs from chasing invalid pointers. This appears to be the
default behaviour for gen5, and so we just need to tweak gen4 to match.
v4: Fix spelling of ECOSKPD and discover it already exists
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190419172720.5462-1-chris@chris-wilson.co.uk
Ironlake does support being able to saving and reloading context specific
registers between contexts, providing isolation of the basic GPU state
(as programmable by userspace). This allows userspace to assume that the
GPU retains their state from one batch to the next, minimising the
amount of state it needs to reload, or manually save and restore.
v2: Fix off-by-one in reading CXT_SIZE, and add a comment that the
CXT_SIZE and context-layout do not match in bspec, but the difference is
irrelevant as we overallocate the full page anyway (Ville).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190419111749.3910-2-chris@chris-wilson.co.uk
Despite what I think the prm recommends, commit f2253bd985
("drm/i915/ringbuffer: EMIT_INVALIDATE after switch context") turned out
to be a huge mistake when enabling Ironlake contexts as the GPU would
hang on either a MI_FLUSH or PIPE_CONTROL immediately following the
MI_SET_CONTEXT of an active mesa context (more vanilla contexts, e.g.
simple rendercopies with igt, do not suffer).
Ville found the following clue,
"[DevCTG+]: For the invalidate operation of the pipe control, the
following pointers are affected. The
invalidate operation affects the restore of these packets. If the pipe
control invalidate operation is completed
before the context save, the indirect pointers will not be restored from
memory.
1. Pipeline State Pointer
2. Media State Pointer
3. Constant Buffer Packet"
which suggests by us emitting the INVALIDATE prior to the MI_SET_CONTEXT,
we prevent the context-restore from chasing the dangling pointers within
the image, and explains why this likely prevents the GPU hang.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190419111749.3910-1-chris@chris-wilson.co.uk
Imre Deak