Back in 2014, commit fb7023e0 ("drm/i915: BDW: Adding Reserved PCI
IDs.") added the reserved PCI IDs in order to try to make sure we had
working drivers in case we ever released products using these IDs
(since we had instances of this type of problem in the past). The
problem is that the patch only touched the macros used by
early-quirks.c and by the user space components that rely on
i915_pciids.h, it didn't touch the macros used by i915_pci.c. So we
correctly handled the stolen memory for these theoretical IDs, but we
didn't actually drive the devices from i915.ko.

So this patch fixes the original commit by actually making i915.ko
drive these IDs, which was the goal. There's no information on what
would be the GT count on these IDs, so we just go with the safer
intel_broadwell_info, at the risk of ignoring a possibly inexistent
BSD2_RING.

I did some checking, and it seems that these IDs are driven by
intel-gpu-tools, xf86-video-intel and libdrm (since they contain old
copies of i915_pciids.h), but they are not checked by mesa.

The alternative to this patch would be to just assume we're actually
never going to use these IDs, and then remove them from our ID lists
and make sure our user space components sync the latest i915_pciids.h
copy. I'm fine with either approaches, as long as we make sure that
every component tries to drive the same list of PCI IDs.

Fixes: fb7023e0 ("drm/i915: BDW: Adding Reserved PCI IDs.")
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483473860-17644-3-git-send-email-paulo.r.zanoni@intel.com

The code was moved, but the comment not updated. It confused me.

Fixes: 7f4c6284 ("drm/i915: Assign hwmode after encoder state readout")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161219082423.27798-6-daniel.vetter@ffwll.ch

After commit 1c74eeaf ("drm/i915: Move number of scalers initialization to
runtime init"), scalers are not initialized properly for skl and glk
since num_scalers is left as 0 for those platforms.

Fixes: 1c74eeaf ("drm/i915: Move number of scalers initialization to runtime init")
Cc: Nabendu Maiti <nabendu.bikash.maiti@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483365281-10569-1-git-send-email-ander.conselvan.de.oliveira@intel.com

Ville explained that the wakelock was being acquired during set-idle in
order to flush the voltage change from the punit.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170102152845.32352-1-chris@chris-wilson.co.ukReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

This function is only used by intel_guc_send() and it doesn't
need to be exposed outside of intel_uc.o file. Also when defined
as static, compiler will generate smaller code. Additionally let
it take guc param instead dev_priv to match function name.
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161220115531.76120-1-michal.wajdeczko@intel.com

In future patches, we require greater flexibility in describing
the number of scalers available on each CRTC. To ease that transition
we move the current assignment to intel_device_info.

Scaler structure initialisation is done if scaler is available on the CRTC.
Gen9 check is not required as on depending upon numbers of scalers we
initialize scalers or return without doing anything in skl_init_scalers.

v3: Changed skl_init_scaler to intel_crtc_init_scalers

v2: Added Chris's comments.
Signed-off-by: NNabendu Maiti <nabendu.bikash.maiti@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480398794-22741-1-git-send-email-nabendu.bikash.maiti@intel.com

The function intel_atomic_get_shared_dpll_state() is only called from
intel_dpll_mgr.c and it concerns the same data structures as the other
functions in that file, so move it there and make it static.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-8-git-send-email-ander.conselvan.de.oliveira@intel.com

DRRS is not yet kerneldoc despite the allusion prior to enum
drrs_refresh_rate_type. Drop the '**' to avoid the warnings from
make htmldocs.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161231112012.29263-4-chris@chris-wilson.co.uk

The existing kerneldoc was outdated, so time for a refresh.

v2: Use single line kdoc, mention functions for manipulation
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161231112012.29263-3-chris@chris-wilson.co.uk

Parameter - no.
Parameter: yes.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161231112012.29263-2-chris@chris-wilson.co.uk

The read of the page pin count and the bind count are unordered,
presenting races in the assert and it firing off incorrectly. Prevent
this by restricting the assert to the vma bind/unbind routines where we
have local cpu ordering between the two.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161231112012.29263-1-chris@chris-wilson.co.uk

Remove the IS_PLATFORM() macros from intel_dump_pipe_config() and split
that logic in platform specific implementations inside the dpll code,
accessed through a platform independent interface.

v2: Rebase.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-7-git-send-email-ander.conselvan.de.oliveira@intel.com

The documentation for most of the non-static members and structs were
missing. Fix that.

v2: Fix typos (Durga)

v3: Rebase.
    Fix make docs warnings.
    Document more.

v4: capitilize CRTC; say that the prepare hook is a nop if the DPLL is
    already enabled; link to struct intel_dpll_hw_state from @hw_state
    field in struct intel_shared_dpll_state; reorganize DPLL flags; link
    intel_shared_dpll_state to other structs and functions. (Daniel)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-6-git-send-email-ander.conselvan.de.oliveira@intel.com

The hook is called from intel_prepare_shared_dpll(). The name doesn't
make sense after all the changes to modeset code. So just call it
prepare.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NDurgadoss R <durgadoss.r@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-5-git-send-email-ander.conselvan.de.oliveira@intel.com

Struct intel_shared_dpll_config is used to hold the state of the DPLL in
the "atomic" sense, so call it state like everything else atomic.

v2: Rebase
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-4-git-send-email-ander.conselvan.de.oliveira@intel.com

The function intel_shared_dpll_commit() performs the equivalent of
drm_atomic_helper_swap_state() for the shared dpll state, which is not
handled by the helpers. So make it do a full swap of the state and
rename it for consistency.

v2: Fix typo in the commit message. (Durga)
v3: Rebase.
v4: Swap the states instead of just renaming the function. (Daniel)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Durgadoss R <durgadoss.r@intel.com> (v2)
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v3)
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-3-git-send-email-ander.conselvan.de.oliveira@intel.com

While the details of getting a shared dpll are wrapped by
intel_get_shared_dpll(), the release was still hand rolled into the
modeset code. Fix that by creating an entry point for releasing the
pll and move that code there.

v2: Take old_dpll from crtc->state instead of crtc_state. (CI)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1483024933-3726-2-git-send-email-ander.conselvan.de.oliveira@intel.com

Insulate users from changes to the internal hole tracking within
struct drm_mm_node by using an accessor for hole_follows.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
[danvet: resolve conflicts in i915_vma.c]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Using mm->color_adjust makes the eviction scanner much tricker since we
don't know the actual neighbours of the target hole until after it is
created (after scanning is complete). To work out whether we need to
evict the neighbours because they impact upon the hole, we have to then
check the hole afterwards - requiring an extra step in the user of the
eviction scanner when they apply color_adjust.

v2: Massage kerneldoc.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222083641.2691-34-chris@chris-wilson.co.uk

Add an assertion to the plain i915_ggtt_offset() to double check that
any offset we hand to the GuC is outside of its unmappable ranges.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161224193146.4402-1-chris@chris-wilson.co.ukReviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

Compute the minimal required hole during scan and only evict those nodes
that overlap. This enables us to reduce the number of nodes we need to
evict to the bare minimum.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222083641.2691-31-chris@chris-wilson.co.uk

Doing the check is trivial (low cost in comparison to overall eviction)
and helps simplify the code.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222083641.2691-29-chris@chris-wilson.co.uk

The scan state occupies a large proportion of the struct drm_mm and is
rarely used and only contains temporary state. That makes it suitable to
moving to its struct and onto the stack of the callers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
[danvet: Fix up etnaviv to compile, was missing a BUG_ON.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

The context has to obey the same offset requirements as the ring,
so we can re-use the same bias value we computed for the ring instead of
unconditionally using GUC_WOPCM_TOP.
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1482537382-28584-2-git-send-email-daniele.ceraolospurio@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

GuC will validate the ring offset and fail if it is in the
[0, GUC_WOPCM_TOP) range. The bias is conditionally applied only
if GuC loading is enabled (we can't check for guc submission enabled as
in other cases because HuC loading requires this fix).

Note that the default context is processed before enable_guc_loading is
sanitized, so we might still apply the bias to its ring even if it is
not needed.

v2: compute the value during ctx init and pass it to
    intel_ring_pin (Chris), updated commit message
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1482537382-28584-1-git-send-email-daniele.ceraolospurio@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As the fence may be signaled concurrently from an interrupt on another
device, it is possible for the list of requests on the timeline to be
modified as we walk it. Take both (the context's timeline and the global
timeline) locks to prevent such modifications.

Fixes: 80b204bc ("drm/i915: Enable multiple timelines")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: <drm-intel-fixes@lists.freedesktop.org>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-10-chris@chris-wilson.co.uk

When creating a partial VMA assert that it first fits with the parent
object, and that if it covers the whole of the parent a normal view was
created instead.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-5-chris@chris-wilson.co.uk

As trimming the sg table is merely an optimisation that gracefully fails
if we cannot allocate a new table, we do not need to report the failure
either.

Fixes: 0c40ce13 ("drm/i915: Trim the object sg table")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-4-chris@chris-wilson.co.uk

When we teardown the backing storage for the phys object, we copy from
the coherent contiguous block back to the shmemfs object, clflushing as
we go. Trying to clflush the invalid sg beforehand just oops and would
be redundant (due to it already being coherent, and clflushed
afterwards).
Reported-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <drm-intel-fixes@lists.freedesktop.org>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-3-chris@chris-wilson.co.uk

The idle work handler is self-arming - if it detects that it needs to
run again it will queue itself from its work handler. Take greater care
when trying to drain the idle work, and double check that it is flushed.

The free worker has a similar issue where it is armed by an RCU task
which may be running concurrently with us.

This should hopefully help with the sporadic WARN_ON(dev_priv->gt.awake)
from i915_gem_suspend.

v2: Reuse drain_freed_objects.
v3: Don't try to flush the freed objects from the shrinker, as it may be
underneath the struct_mutex already.
v4: do while and comment upon the excess rcu_barrier in drain_freed_objects
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-2-chris@chris-wilson.co.uk

Since commit db6c2b41 ("drm/i915: Store the vma in an rbtree under
the object") the vma are once again sorted into GGTT first, then ppGTT
so that the typical case of walking the GGTT vma can stop as soon as we
find a non-ppGTT. Apply that optimisation.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-1-chris@chris-wilson.co.uk

Now that we're disabling L2 clock gating MI_OVERLAY_OFF actually works
on 830, so let's use it.

v2: Nuke the unused dev_priv variable
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222195222.9618-1-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

On enable intel_dsi_enable() directly calls intel_enable_dsi_pll(),
make intel_dsi_disable() also directly call intel_disable_dsi_pll(),
rather then hiding the call in intel_dsi_clear_device_ready(),
no functional changes.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161201202925.12220-7-hdegoede@redhat.com

The upper bits of the vsync width, vsync offset and hsync width
were not parsed from the VBT. Parse these fields in this patch.

V2: Renamed lvds dvo timing structure members and code identation
fix (Jani's review comments)
V3: Corrected commit message, used "from the VBT"
Signed-off-by: NVincente Tsou <vincente.tsou@intel.com>
Signed-off-by: NMadhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1482430993-3265-1-git-send-email-madhav.chauhan@intel.com

BSpec says:
"Overlay Clock Gating Must be Disabled: Overlay & L2 Cache clock gating
must be disabled in order to prevent device hangs when turning off overlay.SW
must turn off Ovrunit clock gating (6200h) and L2 Cache clock gating (C8h)."

We only turned off the overlay clock gating (due to lack of docs I
presume). After a bit of experimentation it looks like the the magic
C8h register lives in the PCI config space of device 0, and the magic
bit appears to be bit 2. Or at the very least this eliminates the GPU
death after MI_OVERLAY_OFF.

L2 clock gating seems to save ~80mW, so let's keep it on unless we need
to actually use the overlay.

Also let's move the OVRUNIT clock gating to the same place since we can,
and 845 supposedly doesn't need it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481131693-27993-11-git-send-email-ville.syrjala@linux.intel.comAcked-by: NChris Wilson <chris@chris-wilson.co.uk>

Extract the primary plane pixel format via plane state when setting up
the overlay colorkey.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481131693-27993-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Use two-dimensional arrays and named initializers to make the
overlay filter coefficient tables easier to parse for humans.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481131693-27993-9-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

The formula in Bspec for computing the overlay SWIDTHSW is overly
obfuscated. Simplify the formula to something that's easily parsed by
humans.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481131693-27993-8-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>