On g33, the documentation states

"HWS_PGA:
 Format = Bits 28:12 of graphics memory address (bits 31:29 MBZ)."

which translates to that the address of the HWS must be below 256MiB,
which is conveniently the mappable aperture.

This also appears to be true (but not documented as so) for gen4 and
gen5. To generalise we force it into the low mappable region for all
non-LLC platforms. If we locate the HWS at the top of the GTT the
machine will hard hang during boot (fails on pnv, gm45, ilk and byt,
but works on snb, ivb, hsw).

v2: Add comments to explain why use PIN_MAPPABLE even though we have
    no intention of mapping the object. (Ville)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With RC6 enabled, BYT has an HW issue in determining the right
Gfx busyness.
WA for Turbo + RC6: Use SW based Gfx busy-ness detection to decide
on increasing/decreasing the freq. This logic will monitor C0
counters of render/media power-wells over EI period and takes
necessary action based on these values

v2: Refactor duplicate code. (Ville)

v3: Reformat the comments. (Ville)

v4: Enable required counters and remove unwanted code (Ville)

v5: Added frequency change acceleration support and remove kernel-doc
style comments. (Ville)

v6: Updated comment section and Fix w/a comment. (Ville)
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For whatever reason, MI_DISPLAY_FLIP fails to change tiling mode on
Baytrail, so just use CPU driven mmio flips instead.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76176Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We currently see random GPU hangs when using RCS flips with multiple
pipes on Ivybridge. Now that we have mmio flips, we can fairly cheaply
fallback to using CPU driven flips instead.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77104Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So that we isolate the legacy ringbuffer submission mechanism, which becomes
a good candidate to be abstracted away. This is prep-work for Execlists (which
will its own workload submission mechanism).

No functional changes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Again, it's low-level enough to simply take a ringbuf and nothing
else.

Trivial change.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's simple enough that it doesn't need to know anything about the
engine.

Trivial change.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

More prep work: with Execlists, we are going to start creating a lot
of extra ringbuffers soon, so these functions are handy.

No functional changes.

v2: rename allocate/destroy_ring_buffer to alloc/destroy_ringbuffer_obj
because the name is more meaningful and to mirror a similar function in
the context world: i915_gem_alloc_context_obj(). Change suggested by Brad
Volkin.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A bit of background on the context elements.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Appease checkpatch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is an Execlists preparatory patch, since they make context ID become an
overloaded term:

- In the software, it was used to distinguish which context userspace was
  trying to use.
- In the BSpec, the term is used to describe the 20-bits long field the
  hardware uses to it to discriminate the contexts that are submitted to
  the ELSP and inform the driver about their current status (via Context
  Switch Interrupts and Context Status Buffers).

Initially, I tried to make the different meanings converge, but it proved
impossible:

- The software ctx->id is per-filp, while the hardware one needs to be
  globally unique.
- Also, we multiplex several backing states objects per intel_context,
  and all of them need unique HW IDs.
- I tried adding a per-filp ID and then composing the HW context ID as:
  ctx->id + file_priv->id + ring->id, but the fact that the hardware only
  uses 20-bits means we have to artificially limit the number of filps or
  contexts the userspace can create.

The ctx->user_handle renaming bits are done with this Cocci patch (plus
manual frobbing of the struct declaration):

    @@
    struct intel_context c;
    @@
    - (c).id
    + c.user_handle

    @@
    struct intel_context *c;
    @@
    - (c)->id
    + c->user_handle

Also, while we are at it, s/DEFAULT_CONTEXT_ID/DEFAULT_CONTEXT_HANDLE and
change the type to unsigned 32 bits.

v2: s/handle/user_handle and change the type to uint32_t as suggested by
Chris Wilson.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have already advanced that Logical Ring Contexts have their own kind
of backing objects, but everything will be better explained in the Execlists
series. For now, suffice it to say that the current backing object is only
ever used with the render ring, so we're making this fact more explicit
(which is a good reason on its own).

As for the is_initialized flag, we only use to signify that the render state
has been initialized (a.k.a. golden context, a.k.a. null context). It doesn't
mean anything for the other engines, so make that distinction obvious.

Done with the following Coccinelle patch (plus manual frobbing of the struct):

    @@
    struct intel_context c;
    @@
    - (c).obj
    + c.legacy_hw_ctx.rcs_state

    @@
    struct intel_context *c;
    @@
    - (c)->obj
    + c->legacy_hw_ctx.rcs_state

    @@
    struct intel_context c;
    @@
    - (c).is_initialized
    + c.legacy_hw_ctx.initialized

    @@
    struct intel_context *c;
    @@
    - (c)->is_initialized
    + c->legacy_hw_ctx.initialized

This Execlists prep-work patch has been suggested by Chris Wilson and Daniel
Vetter separately.

Initially, it was two separate patches:
drm/i915: Rename ctx->obj to ctx->rcs_state
drm/i915: Make it obvious that ctx->id is merely a user handle
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: s/id/is_initialized/ to fix the subject and resolve a
conflict in i915_gem_context_reset. Also introduce a new lctx local
variable to avoid overtly long lines.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is preparatory work for Execlists: we plan to use it later to
allocate our own context objects (since Logical Ring Contexts do
not have the same kind of backing objects).

No functional changes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To achieve further power savings during system freeze (aka connected
standby, or s0ix) we have to send a PCI_D1 opregion notification. As
the information about the state we're entering (system freeze,
suspend to ram or suspend to disk) is only available through the ACPI
subsystem, make this support depend on the relevant kconfig option.
Things will still work if this option isn't set, albeit with less than
optimial power saving.

This also fixes a compile breakage when the option is not set introduced
in

commit e5747e3a
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Thu Jun 12 08:35:47 2014 -0700

    drm/i915: send proper opregion notifications on suspend/resume
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make the assumption that media workloads are not as latency sensitive
for __wait_seqno, and that upclocking the GPU does not affect the BLT
engine. Under that assumption, we only wait to forcibly upclock the GPU
when we are stalling for results from the render pipeline.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the new checks in place, we can see we're doing things backwards,
so fix them up per the spec.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As Ville points out, it's possible/probable we don't actually need this.
Potentially, this validates the letter of the spec, and not the spirit.

Ville:
> I discussed this on irc w/ Ben, and I was suggesting we don't need to
> poll. Polling apparently can be used as a workaround for certain
> hardware issues, but it looks like those issues shouldn't affect us,
> for the momemnt at least. So my suggestion was to try w/o polling
> first (since there could be some power cost to polling) and add the
> poll bit if problems arise.

Rodrigo: Spec suggests this as an W/A for GT3. However semaphores didn't
worked in my BDW GT2 on Signal Mode. So pool mode is definitely needed.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Tested-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Simple debugfs file to display the current state of semaphores. This is
useful if you want to see the state without hanging the GPU.

NOTE: This patch is optional to the series.

NOTE2: Like the GPU error state collection, the reads are currently
incoherent.

v2 (Rodrigo): * Iterate only on active rings.
   	      * s/ring_buffer/engine_cs.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since the semaphore information is in an object, just dump it, and let
the user parse it later.

NOTE: The page being used for the semaphores are incoherent with the
CPU. No matter what I do, I cannot figure out a way to read anything but
0s. Note that the semaphore waits are indeed working.

v2: Don't print signal, and wait (they should be the same). Instead,
print sync_seqno (Chris)

v3: Free the semaphore error object (Chris)

v4: Fix semaphore offset calculation during error state collection
(Ville)

v5: VCS2 rebase
Make semaphore object error capture coding style consistent (Ville)
Do the proper math for the signal offset (Ville)

v6: Fix small conflicts on rebase and s/ring_buffer/engine_cs (Rodrigo)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: s/ring_buffer/engine_cs (Rodrigo)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Ipehr just carries Dword 0 and on Gen 8, offsets are located
on Dword 2 and 3 of MI_SEMAPHORE_WAIT.

This implementation was based on Ben's work and on Ville's suggestion for Ben

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Fixup format string.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Semaphore waits use a new instruction, MI_SEMAPHORE_WAIT. The seqno to
wait on is all well defined by the table in the previous patch. There is
nothing else different from previous GEN's semaphore synchronization
code.

v2: Update macros to not require the other ring's ring->id (Chris)

v3: Add missing VCS2 gen8_ring_wait init besides
    s/ring_buffer/engine_cs (Rodrigo)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Semaphore signalling works similarly to previous GENs with the exception
that the per ring mailboxes no longer exist. Instead you must define
your own space, somewhere in the GTT.

The comments in the code define the layout I've opted for, which should
be fairly future proof. Ie. I tried to define offsets in abstract terms
(NUM_RINGS, seqno size, etc).

NOTE: If one wanted to move this to the HWSP they could. I've decided
one 4k object would be easier to deal with, and provide potential wins
with cache locality, but that's all speculative.

v2: Update the macro to not need the other ring's ring->id (Chris)
Update the comment to use the correct formula (Chris)

v3: Move the macros the ringbuffer.h to prevent churn in next patch
(Ville)

v4: Fixed compilation rebase conflict
commit 1ec9e26d
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Feb 14 14:01:11 2014 +0100

    drm/i915: Consolidate binding parameters into flags

v5: VCS2 rebase
Replace hweight_long with hweight32

v6 (Rodrigo): * Add missed VC2 gen8 ring signal init
   	      * fixing conflicst on rebase
    	      * minor fixes on address table
	      * remove WARN_ON
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
[danvet: s/BUG_ON/WARN_ON/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the ring mask we now have an easy way to know the number of rings
in the system, and therefore can accurately predict the number of dwords
to emit for semaphore signalling. This was not possible (easily)
previously.

There should be no functional impact, simply fewer instructions emitted.

While we're here, simply do the round up to 2 instead of the fancier
rounding we did before, which rounding up per mbox, ie 4. This also
allows us to drop the unnecessary MI_NOOP, so not really 4, 3.

v2: Use 3 dwords instead of 4 (Ville)
Do the proper calculation to get the number of dwords to emit (Ville)
Conditionally set .sync_to when semaphores are enabled (Ville)

v3: Rebased on VCS2
Replace hweight_long with hweight32 (Ville)

v4: Pull out the accidentally squashed hunk from the next patch after
rebase (Daniel).

v5: Fix conflict after rebase (Rodrigo)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v1)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Gen8 has already had some differentiation with how it handles rings.
Semaphores bring yet more differences, and now is as good a time as any
to do the split.

Also, since gen8 doesn't actually use semaphores up until this point,
put the proper "NULL" values in for the mbox info.

v2: v1 had a stale commit message

v3: Move everything in the is_semaphore_enabled() check

v4: VCS2 rebase
Remove double assignment of signal in render ring (Ville)

v5: Adding missed VCS2 signal init on gen8+ (Rodrigo)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ring index calculation table was out of date after other rings were added,
although the formula is flexible and scale when adding new rings.

So this patch just update the comments and add a brief explanation
why to use sync_seqno[ring index].
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It just fix a typo.

v2: removing underscore to let this like all other ring names (Oscar)

Cc: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by (v1): Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The 'i915_driver_preclose()' function has a parameter called 'file_priv'.
However, this is misleading as the structure it points to is a 'drm_file' not a
'drm_i915_file_private'. It should be named just 'file' to avoid confusion.
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The always-on power well pixel path on haswell is routed such that it
bypasses the panel fitter when we use is. Which means the pfit CRC
source won't work in that configuration.

Add a new disallow-bypass flags to the pfit pipe config state and set
it when we want to use the pf CRC. Results in a bit of flicker, but
should get the job done. We'll also undo do it afterwards to make sure
other tests arent' negatively affected.

Totally untested due to lack of hsw laptops around here.

v2: s/disallow_bypass/force_power_well_on/ to avoid a double negative
(Damien).

v3: force_thru because roadsigns.

v4: Don't forget the power wells! Also note that until the runtime pm
for DPMS series is fully merged the simple disable/enable trick won't
work since the ->crtc_mode_set callback is still required to do nasty
things. This stuff is tricky, but I think by both fixing up
get_crtc_power_domains and the debugfs wa code we should always
grab/drop the additional power well correctly.

v5: Wrap in () as suggested by Damien to avoid setting reserved values
for the edp transcoder path on bdw+

References: https://bugs.freedesktop.org/show_bug.cgi?id=72864
Cc: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Tested-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The workaround to limit SDE poly depth FIFO to 2 is not applied because
3D Chicken-3 mask bit is not set.

WaLimitSizeOfSDEPolyFifo is only for BDW-A and could be removed.
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since the root cause is understood now and with the fix

   commit 564ed191
   Author: Imre Deak <imre.deak@intel.com>
   Date:   Fri Jun 13 14:54:21 2014 +0300

       drm/i915: gmch: fix stuck primary plane due to memory self-refresh mode

in place the magic for G4x chipsets introduced with commit

   commit 61bc95c1
   Author: Egbert Eich <eich@suse.com>
   Date:   Mon Mar 4 09:24:38 2013 -0500

       DRM/i915: On G45 enable cursor plane briefly after enabling the display plane.

to avoided occasional screen blanking on mode changes can finally
be removed.
It's been verified that Imre's fix also resolves the said issue.
Signed-off-by: NEgbert Eich <eich@suse.de>
Tested-by: NStefan Dirsch <sndirsch@suse.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As pointed out before we don't have a reliable way to read back ips
status on BDW without the risk to disable it when reading.
However now we are pretending that IPS on BDW is always on and getting
people confused about it.

So this patch allows people to know if ips was ever attempted to be enabled.
Even if the current status is impossible to be ascertain.

v2: (spotted by Paulo):
     * A version that at least compiles
     * with more clear messages
     * let Cheryview on the safe side until we aren't sure that checking ips
       state on ips won't disable it.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We're forgetting to unpin the last_context from the ggtt at GPU reset
time. This leads to the vma pin_count leaking at every reset if the
last context wasn't the ring default context. Further use of the same
context will trigger the pin_count check in i915_gem_object_pin() and
userspace will be faced with EBUSY as a result.

This plaques kms_flip rather badly since it performs lots of resets,
and every fd has its own default context these days.

Fix the problem by properly unpinning the last context at reset.

This regression seems to back to

commit acce9ffa
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Fri Dec 6 14:11:03 2013 -0800

   drm/i915: Better reset handling for contexts

Testcase: igt/gem_ctx_exec/reset-pin-leak
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The digital ports from Ironlake and up have the ability to distinguish
between long and short HPD pulses. Displayport 1.1 only uses the short
form to request link retraining usually, so we haven't really needed
support for it until now.

However with DP 1.2 MST we need to handle the short irqs on their
own outside the modesetting locking the long hpd's involve. This
patch adds the framework to distinguish between short/long to the
current code base, to lay the basis for future DP 1.2 MST work.

This should mean we get better bisectability in case of regression
due to the new irq handling.

v2: add GM45 support (untested, due to lack of hw)
Signed-off-by: NDave Airlie <airlied@redhat.com>
Reviewed-by: NTodd Previte <tprevite@gmail.com>
[danvet: Fix conflicts in i915_irq.c with Oscar Mateo's irq handling
race fixes and a trivial one in intel_drv.h with the psr code.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Blanking/unblanking the console in a loop on an Asus T100 sometimes
leaves the console blank. After some digging I found that applying

commit 61bc95c1
Author: Egbert Eich <eich@suse.com>
Date:   Mon Mar 4 09:24:38 2013 -0500

    DRM/i915: On G45 enable cursor plane briefly after enabling the display plane.

fixed VLV too.

In my case the problem seemed to happen already during the previous crtc
disabling and went away if I disabled self-refresh mode before disabling
the primary plane.

The root cause for this is that updates from the shadow to live plane
control register are blocked at vblank time if the memory self-refresh
mode (aka max-fifo mode on VLV) is active at that moment. The controller
checks at frame start time if the CPU is in C0 and the self-refresh mode
enable bit is set and if so activates self-reresh mode, otherwise
deactivates it. So to make sure that the plane truly gets disabled before
pipe-off we have to:

1. disable memory self-refresh mode
2. disable plane
3. wait for vblank
4. disable pipe
5. wait for pipe-off

v2:
- add explanation for the root cause from HW team (Cesar Mancini et al)
- remove note about the CPU C7S state, in my latest tests disabling it
  alone didn't make a difference
- add vblank between disabling plane and pipe (Ville)
- apply the same workaround for all gmch platforms (Ville)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVijay Purushothaman <vijay.a.purushothaman@intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Atm it's possible that we enable the memory self-refresh mode before the
watermark levels used by this mode are programmed with valid values. So
move the enabling after we programmed the WM levels.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVijay Purushothaman <vijay.a.purushothaman@intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This functionality will be also needed by an upcoming patch, so factor
it out. As a bonus this also makes things a bit more uniform across
platforms. Note that this also changes the register read-modify-write
to a simple write during disabling. This is what we do during enabling
anyway and according to the spec all the relevant bits are reserved-MBZ
or reserved with a 0 default value.

v2:
- unchanged
v3:
- fix missing cxsr disabling on pineview (Deepak)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that the CMNRESET deassert is part of the cmnlane power well,
intel_reset_dpio() is called too late to make any difference. We've
deasserted CMNRESET by that time, and so the off+on toggle w/a will
never kick in.

Move the workaround to intel_power_domains_init_hw() where it gets
called before we enable the init power domain.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Remove the clutter in __vlv_set_power_well() by moving the cmnlane
handling into custom enable/disable hooks for the cmnlane.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have a slightly different way of readoing out the cdclk in
gmbus_set_freq(). Kill that and just call .get_display_clock_speed().

Also need to remove the GMBUSFREQ update from intel_i2c_reset() since
that gets called way too early. Let's do it in intel_modeset_init_hw()
instead, and also pull the initial vlv_cdclk_freq update there from
init_clock gating.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>