We only need the active reference to keep the object alive after the
handle has been deleted (so as to prevent a synchronous gem_close). Why
then pay the price of a kref on every execbuf when we can insert that
final active ref just in time for the handle deletion?
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-6-chris@chris-wilson.co.uk
Our low-level wait routine has evolved from our generic wait interface
that handled unlocked, RPS boosting, waits with time tracking. If we
push our GEM fence tracking to use reservation_objects (required for
handling multiple timelines), we lose the ability to pass the required
information down to i915_wait_request(). However, if we push the extra
functionality from i915_wait_request() to the individual callsites
(i915_gem_object_wait_rendering and i915_gem_wait_ioctl) that make use
of those extras, we can both simplify our low level wait and prepare for
extending the GEM interface for use of reservation_objects.
v2: Rewrite i915_wait_request() kerneldocs
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-4-chris@chris-wilson.co.uk
We will need to wait on DMA completion (as signaled via struct fence)
before executing our i915_gem_request. Therefore we want to expose a
method for adding the await on the fence itself to the request.
v2: Add a comment detailing a failure to handle a signal-on-any
fence-array.
v3: Pretend that magic numbers don't exist.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-1-chris@chris-wilson.co.uk
This macro's name is a bit misleading; it doesn't actually iterate over
all planes since it omits the cursor plane. Its only uses are in gen9
code which is using it to iterate over the universal planes (which we
treat as primary+sprites); in these cases the legacy cursor registers
are programmed independently if necessary. The macro's iterator value
(0 for primary plane, spritenum+1 for each secondary plane) also isn't
meaningful outside the gen9 context where the hardware considers them to
all be "universal" planes that follow this numbering.
This is just a renaming/clarification patch with no functional change.
However it will make the subsequent patches more clear.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477522291-10874-2-git-send-email-matthew.d.roper@intel.com
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
The port registers related to the phys in broxton map to different
channels and specific phys. Make that mapping explicit.
v2: Pass enum dpio_phy to macros instead of mmio base. (Imre)
v3: Fix typo in macros. (Imre)
v4: Also change variables from u32 to enum dpio_phy. (Imre)
Remove leftovers from previous version. (Imre)
v5: Actually git add the changes.
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476863940-6019-1-git-send-email-ander.conselvan.de.oliveira@intel.com
Comment mentioned use of intel_uncore_forcewake_irq{unlock, lock}
functions which are nonexistent (and never were).
The description was also incomplete and could cause confusion. Updated
comment is more elaborate on usage and caveats.
v2: mention __locked variant of intel_uncore_forcewake_{get,put} instead
of plain ones
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilsono.c.uk>
[Mika: removed two superfluous lines on comment noted by Chris]
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477399682-3133-1-git-send-email-arkadiusz.hiler@intel.com
As well as knowing when the error occurred, it is more interesting to me
to know how long after booting the error occurred, and for good measure
record the time since last hw initialisation.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161025121602.1457-1-chris@chris-wilson.co.uk
Added the dump of GuC log buffer to i915 error state, as the contents of
GuC log buffer would also be useful to determine that why the GPU reset
was triggered.
v2:
- For uniformity use existing helper function print_error_obj() to
dump out contents of GuC log buffer, pretty printing is better left
to userspace. (Chris)
- Skip the dumping of GuC log buffer when logging is disabled as it
won't be of any use.
- Rebase.
v3: Rebase.
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Akash Goel <akash.goel@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
There are certain types of interrupts which Host can receive from GuC.
GuC ukernel sends an interrupt to Host for certain events, like for
example retrieve/consume the logs generated by ukernel.
This patch adds support to receive interrupts from GuC but currently
enables & partially handles only the interrupt sent by GuC ukernel.
Future patches will add support for handling other interrupt types.
v2:
- Use common low level routines for PM IER/IIR programming (Chris)
- Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
- Replace disabling of wake ref asserts with rpm get/put (Chris)
v3:
- Update comments for more clarity. (Tvrtko)
- Remove the masking of GuC interrupt, which was kept masked till the
start of bottom half, its not really needed as there is only a
single instance of work item & wq is ordered. (Tvrtko)
v4:
- Rebase.
- Rename guc_events to pm_guc_events so as to be indicative of the
register/control block it is associated with. (Chris)
- Add handling for back to back log buffer flush interrupts.
v5:
- Move the read & clearing of register, containing Guc2Host message
bits, outside the irq spinlock. (Tvrtko)
v6:
- Move the log buffer flush interrupt related stuff to the following
patch so as to do only generic bits in this patch. (Tvrtko)
- Rebase.
v7:
- Remove the interrupts_enabled check from gen9_guc_irq_handler, want to
process that last interrupt also before disabling the interrupt, sync
against the work queued by irq handler will be done by caller disabling
the interrupt.
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Akash Goel <akash.goel@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
So far PM IER/IIR/IMR registers were being used only for Turbo related
interrupts. But interrupts coming from GuC also use the same set.
As a precursor to supporting GuC interrupts, added new low level routines
so as to allow sharing the programming of PM IER/IIR/IMR registers between
Turbo & GuC.
Also similar to PM IMR, maintaining a bitmask for PM IER register, to allow
easy sharing of it between Turbo & GuC without involving a rmw operation.
v2:
- For appropriateness & avoid any ambiguity, rename old functions
enable/disable pm_irq to mask/unmask pm_irq and rename new functions
enable/disable pm_interrupts to enable/disable pm_irq. (Tvrtko)
- Use u32 in place of uint32_t. (Tvrtko)
v3:
- Rename the fields pm_irq_mask & pm_ier_mask and do some cleanup. (Chris)
- Rebase.
v4: Fix the inadvertent disabling of User interrupt for VECS ring causing
failure for certain IGTs.
v5: Use dev_priv with HAS_VEBOX macro. (Tvrtko)
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Akash Goel <akash.goel@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
At the moment, we have dependency on the RPM as a barrier itself in both
i915_gem_release_all_mmaps() and i915_gem_restore_fences().
i915_gem_restore_fences() is also called along !runtime pm paths, but we
can move the markup of lost fences alongside releasing the mmaps into a
common i915_gem_runtime_suspend(). This has the advantage of locating
all the tricky barrier dependencies into one location.
v2: Just mark the fence as invalid (fence->dirty) so that upon waking we
will be sure to clear the fence after use, or restore it to the correct
value before use. This makes sure that if the fence is left intact
across the sleep, we do not leave it pointing to a region of GTT for the
next unsuspecting user.
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Imre Deak <imre.deak@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-5-chris@chris-wilson.co.uk
We only used the RPM sequence checking inside the lowlevel GTT
accessors, when we had to rely on callers taking the wakeref on our
behalf. Now that we take the RPM wakeref inside the GTT management
routines themselves, we can forgo the sanitycheck of the callers.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-4-chris@chris-wilson.co.uk
Now that we have reduced the access to the list to either (a) under the
struct_mutex whilst holding the RPM wakeref (so that concurrent writers to
the list are serialised by struct_mutex) and (b) under the atomic
runtime suspend (which cannot run concurrently with any other accessor due
to the atomic nature of the runtime suspend) we can remove the extra
locking around the list itself.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-3-chris@chris-wilson.co.uk
We want to decouple RPM and struct_mutex, but currently RPM has to walk
the list of bound objects and remove userspace mmapping before we
suspend (otherwise userspace may continue to access the GTT whilst it is
powered down). This currently requires the struct_mutex to walk the
bound_list, but if we move that to a separate list and lock we can take
the first step towards removing the struct_mutex.
v2: Split runtime suspend unmapping vs regular unmapping, to make the
locking (and barriers) clearer. Add the object to the userfault_list
prior to inserting the first PTE, the race between add/revoke depends
upon struct_mutex for regular unmappings and rpm for runtime-suspend.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-1-chris@chris-wilson.co.uk
gvt-next-fix-2016-10-20
This contains fix for first pull request.
- clean up header mess between i915 core and gvt
- new MAINTAINERS item
- new kernel-doc section
- fix compiling warnings
- gvt gem fix series from Chris
- fix for i915 intel_engine_cs change
- some sparse fixes from Changbin
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
If the kernel is old, more than a few releases old, chances are that the
user is using an old kernel for a good reason, despite there being GPU
hangs. After 180days since driver release stop suggesting that they
should send those reports upstream.
[Since Daniel acked this I expect he will pick up the dim patch to
automatically update the DRIVER_TIMESTAMP everytime we tag a new
release.]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161014134428.29582-1-chris@chris-wilson.co.uk
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
i915 core should only call functions and structures exposed through
intel_gvt.h. Remove internal gvt.h and i915_pvinfo.h.
Change for internal intel_gvt structure as private handler which
not requires to expose gvt internal structure for i915 core.
v2: Fix per Chris's comment
- carefully handle dev_priv->gvt assignment
- add necessary bracket for macro helper
- forward declartion struct intel_gvt
- keep free operation within same file handling alloc
v3: fix use after free and remove intel_gvt.initialized
v4: change to_gvt() to an inline
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Now that we've make skl_wm_levels make a little more sense, we can
remove all of the redundant wm information. Up until now we'd been
storing two copies of all of the skl watermarks: one being the
skl_pipe_wm structs, the other being the global wm struct in
drm_i915_private containing the raw register values. This is confusing
and problematic, since it means we're prone to accidentally letting the
two copies go out of sync. So, get rid of all of the functions
responsible for computing the register values and just use a single
helper, skl_write_wm_level(), to convert and write the new watermarks on
the fly.
Changes since v1:
- Fixup skl_write_wm_level()
- Fixup skl_wm_level_from_reg_val()
- Don't forget to copy *active to intel_crtc->wm.active.skl
Changes since v2:
- Fix usage of wrong cstate
Changes since v3 (by Paulo):
- Rebase
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v2)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476814189-6062-1-git-send-email-paulo.r.zanoni@intel.com
In many places, we try to count pages using a 32 bit integer. That
implies if we are asked to create an object larger than 43bits, we will
subtly crash much later. Catch this on the boundary, and add a warning
to remind ourselves later on our exabyte systems.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161018120251.25043-2-chris@chris-wilson.co.uk
Internally we allow for using more objects than a single process can
allocate, i.e. we allow for a 64bit GPU address space even on a 32bit
system. Using size_t may oveerflow.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161018120251.25043-1-chris@chris-wilson.co.uk
Many GEN9 boards come with on-board lspcon cards.
Fot these boards, VBT configuration should properly point out
if a particular port contains lspcon device, so that driver can
initialize it properly.
This patch adds a utility function, which checks the VBT flag
for lspcon bit, and tells us if a port is configured to have a
lspcon device or not.
V2: Fixed review comments from Ville
- Do not forget PORT_D while checking lspcon for GEN9
V3: Addressed review comments from Rodrigo
- Create a HAS_LSPCON() macro for better use case handling.
- Do not dump warnings for non-gen-9 platforms, it will be noise.
V4: Rebase
V5: Rebase
V6: Pass dev_priv to HAS_LSPCON() macro
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476455212-27893-4-git-send-email-shashank.sharma@intel.com
Having skl_wm_level contain all of the watermarks for each plane is
annoying since it prevents us from having any sort of object to
represent a single watermark level, something we take advantage of in
the next commit to cut down on all of the copy paste code in here.
Changes since v1:
- Style nitpicks
- Fix accidental usage of i vs. PLANE_CURSOR
- Split out skl_pipe_wm_active_state simplification into separate patch
Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Next part of cleaning up the watermark code for skl. This is easy, since
it seems that we never actually needed to keep track of the linetime in
the skl_wm_values struct anyway.
Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
First part of cleaning up all of the skl watermark code. This moves the
structures for storing the ddb allocations of each pipe into
intel_crtc_state, along with moving the structures for storing the
current ddb allocations active on hardware into intel_crtc.
Changes since v1:
- Don't replace alloc->start = alloc->end = 0;
Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Saves 944 bytes of .rodata strings and 128 bytes of .text.
v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Saves 864 bytes of .rodata strings and ~100 of .text.
v2: Add parantheses around dev_priv. (Ville Syrjala)
v3: Rebase.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Saves 1392 bytes of .rodata strings.
Also change a few function/macro prototypes in i915_gem_gtt.c
from dev to dev_priv where it made more sense to do so.
v2: Add parantheses around dev_priv. (Ville Syrjala)
v3: Mention function prototype changes. (David Weinehall)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Saves 1016 bytes of .rodata strings and couple hundred of .text.
v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
This saves 3248 bytes of .rodata strings.
v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
With the possibility of addition of many more number of rings in future,
the drm_i915_private structure could bloat as an array, of type
intel_engine_cs, is embedded inside it.
struct intel_engine_cs engine[I915_NUM_ENGINES];
Though this is still fine as generally there is only a single instance of
drm_i915_private structure used, but not all of the possible rings would be
enabled or active on most of the platforms. Some memory can be saved by
allocating intel_engine_cs structure only for the enabled/active engines.
Currently the engine/ring ID is kept static and dev_priv->engine[] is simply
indexed using the enums defined in intel_engine_id.
To save memory and continue using the static engine/ring IDs, 'engine' is
defined as an array of pointers.
struct intel_engine_cs *engine[I915_NUM_ENGINES];
dev_priv->engine[engine_ID] will be NULL for disabled engine instances.
There is a text size reduction of 928 bytes, from 1028200 to 1027272, for
i915.o file (but for i915.ko file text size remain same as 1193131 bytes).
v2:
- Remove the engine iterator field added in drm_i915_private structure,
instead pass a local iterator variable to the for_each_engine**
macros. (Chris)
- Do away with intel_engine_initialized() and instead directly use the
NULL pointer check on engine pointer. (Chris)
v3:
- Remove for_each_engine_id() macro, as the updated macro for_each_engine()
can be used in place of it. (Chris)
- Protect the access to Render engine Fault register with a NULL check, as
engine specific init is done later in Driver load sequence.
v4:
- Use !!dev_priv->engine[VCS] style for the engine check in getparam. (Chris)
- Kill the superfluous init_engine_lists().
v5:
- Cleanup the intel_engines_init() & intel_engines_setup(), with respect to
allocation of intel_engine_cs structure. (Chris)
v6:
- Rebase.
v7:
- Optimize the for_each_engine_masked() macro. (Chris)
- Change the type of 'iter' local variable to enum intel_engine_id. (Chris)
- Rebase.
v8: Rebase.
v9: Rebase.
v10:
- For index calculation use engine ID instead of pointer based arithmetic in
intel_engine_sync_index() as engine pointers are not contiguous now (Chris)
- For appropriateness, rename local enum variable 'iter' to 'id'. (Joonas)
- Use for_each_engine macro for cleanup in intel_engines_init() and remove
check for NULL engine pointer in cleanup() routines. (Joonas)
v11: Rebase.
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Akash Goel <akash.goel@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476378888-7372-1-git-send-email-akash.goel@intel.com
Mika wanted to know what requests were pending at the time of a hang as
we now track which requests we have submitted to the hardware.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161013101815.26978-1-chris@chris-wilson.co.uk
