After a bit of irc discussion we've concluded that it would be prudent
to check that callers use the mask/enable paramters correctly. So add
a WARN_ON.

Spurred by Damien's bugfix which added _MASKED_FIELD.

v2: We use WARN_ON(1) a lot to catch default cases in switch blocks
which should always be extended. So this doesn't work really. Dunno
why gcc only started complaining when I've moved the WARN out of the
static inline helper to address a feedback from Jani.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Similar to a patch from Thomas Daniel for lrc contexts. This keeps
both sides somewhat in sync and should make Dave Gordon happy.

Note that both the wa and the golden context init code suffer a bit
from an inssuficient split into driver load and hw init code. Which
means we have a bunch of tests all over the place to check whether the
one-time initialization has been done already or not.

All that one-tim code should be moved into the one-time ring setup
code, but that's work for later.

Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Thomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Remove the function intel_output_name() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Added the request structure's 'uniq' identifier to the trace information. Also
renamed the '_complete' trace event to '_notify' as it actually happens in the
IRQ 'notify_ring()' function. The intention is to add a new '_complete' trace
event which occurs when a request structure is actually marked as complete.
However, at the moment the completion status is re-tested every time the query
is made so there isn't a completion event as such.

v2: New patch added to series.

v3: Rebased to remove completion caching as that is apparently contentious.

Change-Id: Ic9bcde67d175c6c03b96217cdcb6e4cc4aa45d67
For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For debugging purposes, it is useful to be able to uniquely identify a given
request structure as it works its way through the system. This becomes
especially tricky once the seqno value is lazily allocated as then the request
has nothing but its pointer to identify it for much of its life.

Change-Id: Ie76b2268b940467f4cdf5a4ba6f5a54cbb96445d
For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is a general theory that kzmalloc is better/safer than kmalloc, especially
for interesting data structures. This change updates the request structure
allocation to be zero filled.

This also fixes crashes in the reset code. Quoting Mika's patch:

"Clean the request structure on alloc. Otherwise we might end up
referencing uninitialized fields.  This is apparent when we try to
cleanup the preallocated request on ring reset, before any request has
been submitted to the ring.  The request->ctx is foobar and we end up
freeing the foobarness."

Note that this fixes a regression introduced in

commit 9eba5d4a
Author: John Harrison <John.C.Harrison@Intel.com>
Date:   Mon Nov 24 18:49:23 2014 +0000

    drm/i915: Ensure OLS & PLR are always in sync

References: https://bugs.freedesktop.org/show_bug.cgi?id=86959
References: https://bugs.freedesktop.org/show_bug.cgi?id=86962
References: https://bugs.freedesktop.org/show_bug.cgi?id=86992
Change-Id: I68715ef758025fab8db763941ef63bf60d7031e2
For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The display related patches earlier in this series were edited during merge to
improve the request unreferencing. Specifically, the need for de-referencing at
interrupt time was removed. However, the resulting code did a 'deref(req) ; req
= NULL' sequence rather than using the 'req_assign(req, NULL)' wrapper. The two
are functionally equivalent, but using the wrapper is more consistent with all
the other places where requests are assigned.

Note that the whole point of the wrapper is that using it everywhere that
request pointers are assigned means that the reference counting is done
automatically and can't be accidentally forgotten about. Plus it allows simpler
future maintainance if the reference counting mechanisms ever need to change.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we extend the commit_plane handlers for each plane type to be able to
handle fb=0, then we can easily implement plane disable via the
update_plane handler.  The cursor plane already works this way, and this
is the direction we need to go to integrate with the atomic plane
handler.  We can now kill off the type-specific disable functions, as
well as the redundant intel_plane_disable() (not to be confused with
intel_disable_plane()).

Note that prepare_plane_fb() only gets called as part of update_plane
when fb!=NULL (by design, to match the semantics of the atomic plane
helpers); this means that our commit_plane handlers need to handle the
frontbuffer tracking for the disable case, even though they don't handle
it for normal updates.

v2:
 - Change BUG_ON to WARN_ON (Ander/Daniel)

v3:
 - Drop unnecessary plane->crtc check since a previous patch to plane
   update ensures that plane->crtc will always be non-NULL, even for
   disable calls that might pass NULL from userspace.  (Ander)
 - Drop a s/crtc/plane->crtc/ hunk that was unnecessary.  (Ander)

v4:
 - Fix missing whitespace (Ander)

v5:
 - Use state's crtc rather than plane's crtc in
   intel_check_primary_plane().  plane->crtc could be NULL, but we've
   already fixed up state->crtc to ensure it's non-NULL (even if
   userspace passed it as NULL during a disable call).  (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When disabling a plane, it is legal to pass crtc = NULL.  Since planes
on Intel hardware are tied to a fixed CRTC, go ahead and set state->crtc
to the appropriate crtc in cases where it is passed to us as NULL.

In a future patch, we will start using the update handler for plane
disables, so this will help ensure we always have a non-NULL crtc
pointer to work with.
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Our .update_plane() handlers do the same check/prepare/commit/cleanup
steps regardless of plane type.  Consolidate them all into a single
function that calls check/commit through a vtable.
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

All plane update functions need to unpin the old framebuffer when
flipping to a new one.  Pull this logic into a separate function to ease
the integration with atomic plane helpers.

v2: Don't wait for vblank if we don't have an old fb to cleanup (Ander)

v3: Really don't wait for vblank if we don't have an old fb to cleanup.
    Previous version only handled this for primary planes; we need the
    same change on cursors/sprites too!  (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The 'prepare' step for all types of planes are pretty similar;
consolidate the three 'prepare' functions into a single function.  This
paves the way for future integration with the atomic plane handlers.

Note that we pull the 'wait for pending flips' functionality out of the
primary plane's prepare step and place it directly in the 'setplane'
code.  When we move to the atomic plane handlers, this code will be in
the 'atomic begin' step.

v2: Update GEM fb tracking for physical cursors also (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: NBob Paauwe <bob.j.paauwe@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Primary and sprite planes have already been refactored to include a
'prepare' step which handles all the commit-time operations that could
fail (i.e., pinning buffers and such).  Refactor the cursor commit in a
similar manner.

For simplicity and consistency with other plane types, we also switch to
using intel_pin_and_fence_fb_obj() to perform our pinning for
non-physical cursors.  This will allow us to more easily migrate the
code into the atomic 'begin' handler in a plane-agnostic manner in a
future patchset.

v2:
 - Update GEM fb tracking for physical cursors too. (Ander)
 - Use intel_unpin_fb_obj() rather than
   i915_gem_object_unpin_from_display_plane() and do so while holding
   struct_mutex.  (Ander)
 - Update plane->fb in commit_cursor_plane.  This isn't really necessary
   since the DRM core does this for us in __setplane_internal(), but
   doing it in our driver once we know we're going to succeed helps
   avoid confusion. (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

After some refactor intel_primary_plane_setplane() does the same
as intel_pipe_set_base() so we can get rid of it and replace the calls
with intel_primary_plane_setplane().

v2: take Ville's comments:
	- get the right arguments for update_plane()
	- use drm_crtc_get_hv_timing()

v3 (by Matt):
 - Rebase to latest di-nightly codebase
 - Use primary->funcs->update_plane() in __intel_set_mode()
 - Use primary->funcs->disable_plane() in intel_crtc_disable()

v4 (by Matt):
 - Drop redundant calls to intel_crtc_wait_for_pending_flips() before
   calling update_plane() (Ville)
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Acked-and-mourned-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Merge it into the plane update_plane() callback and make other
users use the update_plane() functions instead.

The fb != crtc->cursor->fb was already inside intel_crtc_cursor_set_obj()
so we fold intel_crtc_cursor_set_obj() inside intel_commit_cursor_plane()
and merge both paths into one.

v5 (by Matt):
 - Rebase onto latest di-nightly codebase
 - Drop extra unreference call when we fail to pin (Ville)

Reviewed-by(v4): Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to get hdisplay and vdisplay in a few places so create a
helper to make our job easier.

Note that drm_crtc_check_viewport() and intel_modeset_pipe_config() were
previously making adjustments for doublescan modes and vscan > 1 modes,
which was incorrect.  Using our new helper fixes this mistake.

v2 (by Matt): Use new stereo doubling function (suggested by Ville)

v3 (by Matt):
 - Add missing kerneldoc (Daniel)
 - Use drm_mode_copy() (Jani)

v4 (by Matt):
 - Drop stereo doubling function again; add 'stereo only' flag
   to drm_mode_set_crtcinfo() instead (Ville)

v5 (by Matt):
 - Note behavioral change in drm_crtc_check_viewport() and
   intel_modeset_pipe_config(). (Ander)
 - Describe new adjustment flags in drm_mode_set_crtcinfo()'s
   kerneldoc. (Ander)

Cc: dri-devel@lists.freedesktop.org
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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

We already have it for chv, but was missing for bdw.
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to program both port registers during dual link enable path.

v2: Address review comments by Jani
    - Used a for loop instead of do-while loop.

v3: Used for_each_dsi_port macro instead of for loop

v4: Renamed mode_hactive variable to mode_hdisplay
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to program both port registers during dual link disable path.

v2: Address review comments by Jani
    - Used a for loop instead of do-while loop.

v3: Used for_each_dsi_port macro instead of for loop

v4: Added comments for the usage of AFE latchout bit
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

hactive, hfp, hbp, hsync needs to be halved for dual link MIPI Panels.
Accordingly timing related mmio regs needs to be programmed for both MIPI Ports.

v2: Address review comments by Jani
    - Used a for loop instead of do-while loop

v3: Used for_each_dsi_port macro instead of for loop
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of pipe configuration reg, cck reg to be used for checking whether
DSI Pll is getting locked or not.

v2: dpio_lock unlocked now in case DSI PLL lock fails
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For Dual link MIPI Panels, dsipll clock for both DSI0 and DSI1 needs to be enabled.

v2: Address review comments by Jani
    - Added wait time for PLL to be locked.

v3: separate patch created for cck read for checking PLL to be locked
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For dual link MIPI panels, SHUTDOWN packet needs to send to both Ports
A & C during MIPI encoder disabling sequence. Similarly, TURN ON packet
to be sent to both Ports during MIPI encoder enabling sequence.

v2: Address review comments by Jani
    - Used a for loop instead of do-while loop.

v3: Used for_each_dsi_port macro instead of for loop
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For dual link MIPI Panels, each port needs half of pixel clock. Pixel overlap
can be enabled if needed by panel, then in that case, pixel clock will be
increased for extra pixels.

v2 : Address review comments by Jani
     - Removed the bit mask used for ->dual_link
     - Used DSI instead of MIPI for #define variables

v3: Added the VLV_DISPLAY_BASE to VLV_CHICKEN_3 register
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For Dual Link MIPI Panels, both Port A and Port C should be enabled
during the MIPI encoder enabling sequence. Similarly, during the
disabling sequence, both ports needs to be disabled.

v2: Used for_each_dsi_port macro instead of for loop

v3: Used intel_dsi->ports instead of dual_link var for dual link configuration check

v4: Masking of the required MIPI port bits before writing proper values
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

MI_STORE_DWORD_IMM length has been the same ever since gen4. Rename
the define to avoid potential confusion if someone tries to use this
on pre-gen8.

Also correct the comment on MI_MEM_VIRTUAL bit. It's present on 945,g33
and 965 only.

Cc: Oscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Add USE_GGTT define for g4x+ too.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Release struct_mutex if init_rings() fails.

This is a regression introduced in
commit 35a57ffb
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Nov 20 00:33:07 2014 +0100

    drm/i915: Only init engines once
Reported-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is in preparation of DSI dual link panels. For dual link
panels, few packets needs to be sent to Port A or Port C or both. Based
on the portno from MIPI Sequence Block#53, these sequences needs to be
sent accordingly.

v2: Addressed review comments by Jani
    - port variables named properly
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is in preparation for the DSI dual link
port enable and disable related changes.
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When playing around with debugfs and a HSW machine I noticed that we
were displaying some garbled value in i915_ddb_info. This debugfs file
is only meaningful for gen9+, so don't display anything on earlier
platforms.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Multiple GGTT VMAs per object will be introduced in the near future which will
make it impossible to guarantee normal GGTT view is at the head of the list.

Purpose of this patch is to break this assumption straight away so any
potential hidden assumptions in the code base can be bisected to this
simple patch.

For: VIZ-4544
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: NDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Hardware team updated the recommended translation values for DP/eDP 1.3.
This should help with some stability and HBR2 issues.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Satheeshakrishna M<satheeshakrishna.m@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to do that every time we resume the rings, not just at load.
I've overlooked this in my untangling of the ring init code.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A previous commit introduced engine init changes:

    commit 372ee59699d9 ("drm/i915: Only init engines once")

This broke execlists as intel_lr_context_render_state_init was trying to emit
commands to the RCS for the default context before the ring->init_hw was called.

Made a new gen8_init_rcs_context function and assign in to render ring
init_context.  Moved call to intel_logical_ring_workarounds_emit into
gen8_init_rcs_context to maintain previous functionality.

Moved call to render_state_init from lr_context_deferred_create into
gen8_init_rcs_context, and modified deferred_create to call ring->init_context
for non-default contexts.

Modified i915_gem_context_enable to call ring->init_context for the default
context.

So init_context will now always be called when the hw is ready - in
i915_gem_context_enable for the default context and in lr_context_deferred_create
for other contexts.
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The conversion table can be replaced with simple enough function.

   text	   data	    bss	    dec	    hex	filename
 839688	  10987	     24	 850699	  cfb0b	drivers/gpu/drm/i915/i915.ko
 839224	  10987	     24	 850235	  cf93b	drivers/gpu/drm/i915/i915.ko

Result is 494 saved bytes (.05525%).

v2: - no run on sentences from subject (Chris, Jani)
    - be verbose about the savings (Chris, Daniel)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v1)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that sanity prevails and we have the clean split between software
init and starting the engines we can drop all the "have we allocate
this struct already?" nonsense.

Execlist code could benefit quite a bit more still, but that's for
another patch.
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The same logic can be implemented without it, and it even saves a line
of code.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We can do this.

And now there's finally the clean split between software setup and
hardware setup I kinda wanted since multi-ring support was merged
aeons ago. It only took almost 5 years.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>