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>

If someone is interested in the current cdclk frquency it should
be stable and not in process of changing frquency. Warn if the current
and requested cdclk don't match in .get_display_clock_spee() on vlv.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

VLV Punit doesn't support the 400MHz cdclk option, so we bypass the
Punit and poke at CCK directly. However we forgot to wait for the
frequeency change to complete. Poll the CCK clock status to make sure
the clock has changed before we fire up any pipes.
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>

Drop the cdclk frequency to 200MHz on vlv when all pipes are off. In
theory we should be able to use 200MHz also when the pixel clock is at
most 90% of 200MHz. However in practice all we seem to get is a solid
color picture or an otherwise corrupted display.
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>

Depending on the HPLL frequency one of the supported cdclk frquencies is
either 320MHz or 333MHz. Figure out which one it is to accurately pick
the minimal required cdclk. This would also avoid a warning from the
cdclk code where it compares the actual cdclk read out from the hardware
with a value that was calculated using valleyview_calc_cdclk().
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 standard hook for reading out the current cdclk. Move the VLV
code from valleyview_cur_cdclk() to .get_display_clock_speed().
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>

Avoid using magic values for CCK frequency bits. Also the mask we were
using for the requested frequency was one bit too short. Fix it up.

Note: This also fixes the #define for a mask (spotted by Jesse in his
review).
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Add note about mask change.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use kHz units in vlv cdclk code since that's more customary.

Also replace the precomputed 90% values with *9/10 computation
for extra clarity.
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>

Inlcude the pipe-size and cursor-size in debugfs.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

For Haswell and Broadwell, if the display power well has been disabled,
the display audio controller divider values EM4 M VALUE and EM5 N VALUE
will have been lost. The CDCLK frequency is required for reprogramming them
to generate 24MHz HD-A link BCLK. So provide a private interface for the
audio driver to query CDCLK.

This is a stopgap solution until a more generic interface between audio
and display drivers has been implemented.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NMengdong Lin <mengdong.lin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The GEN FBC unit provides the ability to set a low pass on frames it
attempts to compress. If a frame is less than a certain amount
compressibility (2:1, 4:1) it will not bother. This allows the driver to
reduce the size it requests out of stolen memory.

Unluckily, a few months ago, Ville actually began using this feature for
framebuffers that are 16bpp (not sure why not 8bpp). In those cases, we
are already using this mechanism for a different purpose, and so we can
only achieve one further level of compression (2:1 -> 4:1)

FBC GEN1, ie. pre-G45 is ignored.

The cleverness of the patch is Art's. The bugs are mine.

v2: Update message and including missing threshold case 3 (Spotted by Arthur).

Cc: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Right now, there is no threshold (0 means fail, 1 means 1:1 compression
limit). This is to split the function/non-functional change of the next
patch.

The next patch will start to attempt to reduce the amount of CFB space
we need for dire situations. It will be contained within this function.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

We are already using the size to determine whether or not to free the
object, so there is no functional change there. Almost everything else
has changed to static allocations of the drm_mm_node too.

Aside from bringing this inline with much of our other code, this makes
error paths slightly simpler, which benefits the look of an upcoming
patch.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

use mm.h definition

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Higher RC6 residency is observed using timeout mode
instead of EI mode.  This applies to Broadwell only.
The difference is particularly noticeable with video
playback.
Signed-off-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

It is possible that, by the time we run i915_drm_freeze(),
delayed_resume_work was already queued but did not run yet. If it
still didn't run after intel_runtime_pm_disable_interrupts(), by the
time it runs it will try to change the interrupt registers with the
interrupts already disabled, which will trigger a WARN. We can
reliably reproduce this with the pm_rpm system-suspend test case.

In order to avoid the problem, we have to flush the work before
disabling the interrupts. We could also cancel the work instead of
flushing it, but that would require us to put a runtime PM reference -
and any other resource we may need in the future - in case the work
was already queued, so I believe flushing the work is more
future-proof, although less efficient. But I can also change this part
if someone requests.

Another thing I tried was to move the intel_suspend_gt_powersave()
call to before intel_runtime_pm_disable_interrupts(), but since that
function needs to be called after the interrupts are already disabled,
due to dev_priv->rps.work, this strategy didn't work.

Testcase: igt/pm_rpm/system-suspend
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80517Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Drop WA to fix Voltage not getting dropped to Vmin when Gfx is power
gated for latest VLV revision.

Workaround fixed in Latest VLV revision. Forcing Gfx clk up not needed,
and Requesting the min freq should bring bring the voltage Vnn.

v2: Drop WA for Latest VLV revision (Ville)
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[Jani: modified code comment, reformatted the commit message a bit.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Apparently we can't trust this field on other platforms and need to find
some other way.

This fixes a regression introduced in
commit 27da3bdf
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Fri Apr 4 16:12:07 2014 -0700

    drm/i915: use VBT to determine whether to enumerate the VGA port
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

BDW signals the flip done interrupt immediately after the DSPSURF write
when the plane is disabled. This is true even if we've already armed
DSPCNTR to enable the plane at the next vblank. This causes major
problems for our page flip code which relies on the flip done interrupts
happening at vblank time.

So what happens is that we enable the plane, and immediately allow
userspace to submit a page flip. If the plane is still in the process
of being enabled when the page flip is issued, the flip done gets
signalled immediately. Our DSPSURFLIVE check catches this to prevent
premature flip completion, but it also means that we don't get a flip
done interrupt when the plane actually gets enabled, and so the page
flip is never completed.

Work around this by re-introducing blocking vblank waits on BDW
whenever we enable the primary plane.

I removed some of the vblank waits here:
 commit 6304cd91
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Fri Apr 25 13:30:12 2014 +0300

    drm/i915: Drop the excessive vblank waits from modeset codepaths

To avoid these blocking vblank waits we should start using the vblank
interrupt instead of the flip done interrupt to complete page flips.
But that's material for another patch.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79354Tested-by: NGuo Jinxian <jinxianx.guo@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

crtc->primary->fb may be NULL upon entry to intel_pipe_set_base() if the
primary plane has previously been disabled via the universal plane
interface.  We need to check for NULL before trying to reference
old_fb's obj.

This fixes a regression introduced in

        commit a071fa00
        Author: Daniel Vetter <daniel.vetter@ffwll.ch>
        Date:   Wed Jun 18 23:28:09 2014 +0200

        drm/i915: Introduce accurate frontbuffer tracking

Testcase: igt/kms_universal_plane
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

For MIPI, DSI PLL is configured separately in vlv_configure_dsi_pll
during the DSI enable sequence

Causing WARN dump otherwise in dpio_reads

v2: Add IS_CHERRYVIEW check as suggested by Ville
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Fixes an issue whereby we may race with the table updates (before the
core takes the struct_mutex) and so risk dereferencing a stale pointer in
the iterator for /debugfs/.../i915_gem_objects. For example,

[ 1524.757545] BUG: unable to handle kernel paging request at f53af748
[ 1524.757572] IP: [<c1406982>] per_file_stats+0x12/0x100
[ 1524.757599] *pdpt = 0000000001b13001 *pde = 00000000379fb067 *pte = 80000000353af060
[ 1524.757621] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 1524.757637] Modules linked in: ctr ccm arc4 ath9k ath9k_common ath9k_hw ath snd_hda_codec_conexant mac80211 snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec bnep snd_hwdep rfcomm snd_pcm gpio_ich dell_wmi sparse_keymap snd_seq_midi hid_multitouch uvcvideo snd_seq_midi_event dell_laptop snd_rawmidi dcdbas snd_seq videobuf2_vmalloc videobuf2_memops videobuf2_core usbhid videodev snd_seq_device coretemp snd_timer hid joydev kvm_intel cfg80211 ath3k kvm btusb bluetooth serio_raw snd microcode soundcore lpc_ich wmi mac_hid parport_pc ppdev lp parport psmouse ahci libahci
[ 1524.757825] CPU: 3 PID: 1911 Comm: intel-gpu-overl Tainted: G        W  OE 3.15.0-rc3+ #96
[ 1524.757840] Hardware name: Dell Inc. Inspiron 1090/Inspiron 1090, BIOS A06 08/23/2011
[ 1524.757855] task: f52f36c0 ti: f4cbc000 task.ti: f4cbc000
[ 1524.757869] EIP: 0060:[<c1406982>] EFLAGS: 00210202 CPU: 3
[ 1524.757884] EIP is at per_file_stats+0x12/0x100
[ 1524.757896] EAX: 0000002d EBX: 00000000 ECX: f4cbdefc EDX: f53af700
[ 1524.757909] ESI: c1406970 EDI: f53af700 EBP: f4cbde6c ESP: f4cbde5c
[ 1524.757922]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 1524.757934] CR0: 80050033 CR2: f53af748 CR3: 356af000 CR4: 000007f0
[ 1524.757945] Stack:
[ 1524.757957]  f4cbdefc 00000000 c1406970 f53af700 f4cbdea8 c12e5f15 f4cbdefc c1406970
[ 1524.757993]  0000ffff f4cbde90 0000002d f5dc5cd0 e4e80438 c1181d59 f4cbded8 f4d89900
[ 1524.758027]  f5631b40 e5131074 c1903f37 f4cbdf28 c14068e6 f52648a0 c1927748 c1903f37
[ 1524.758062] Call Trace:
[ 1524.758084]  [<c1406970>] ? i915_gem_object_info+0x510/0x510
[ 1524.758106]  [<c12e5f15>] idr_for_each+0xa5/0x100
[ 1524.758126]  [<c1406970>] ? i915_gem_object_info+0x510/0x510
[ 1524.758148]  [<c1181d59>] ? seq_vprintf+0x29/0x50
[ 1524.758168]  [<c14068e6>] i915_gem_object_info+0x486/0x510
[ 1524.758189]  [<c11823a6>] seq_read+0xd6/0x380
[ 1524.758208]  [<c116d11d>] ? final_putname+0x1d/0x40
[ 1524.758227]  [<c11822d0>] ? seq_hlist_next_percpu+0x90/0x90
[ 1524.758246]  [<c1163e52>] vfs_read+0x82/0x150
[ 1524.758265]  [<c11645d6>] SyS_read+0x46/0x90
[ 1524.758285]  [<c16b8d8c>] sysenter_do_call+0x12/0x22
[ 1524.758298] Code: f5 8f 2a 00 83 c4 6c 31 c0 5b 5e 5f 5d c3 8d 74 26 00 8d bc 27 00 00 00 00 55 89 e5 57 56 53 83 ec 04 3e 8d 74 26 00 83 41 04 01 <8b> 42 48 01 41 08 8b 42 4c 89 d7 85 c0 75 07 8b 42 60 85 c0 74
[ 1524.758461] EIP: [<c1406982>] per_file_stats+0x12/0x100 SS:ESP 0068:f4cbde5c
[ 1524.758485] CR2: 00000000f53af748
Reported-by: NSam Jansen <sam.jansen@starleaf.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sam Jansen <sam.jansen@starleaf.com>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Fallout from

commit 46470fc9
Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date:   Wed May 21 19:01:06 2014 +0300

    drm/i915: Add null state batch to active list

undid the earlier fix of only marking the ctx as initialised after it is
saved by the hardware during a SET_CONTEXT operation:

commit ad1d2199
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Sat Dec 28 13:31:49 2013 -0800

    drm/i915: set ctx->initialized only after RCS
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
[Jani: add reference to the earlier fix in the commit messsage.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>