DMC forces on power well 1 and the misc IO power well by setting the
corresponding request bits both in the BIOS and the DEBUG power well
request registers. This is somewhat unexpected since the firmware should
really just save and restore state but not alter it. We also depend on
being able to disable power well 1, and the misc IO power well before
entering S3/S4 on BXT and SKL or entering DC9 on BXT. To fix this make
sure these request bits are cleared whenever we want to disable the
given power wells.

On SKL there is another twist where the firmware also clears the power
well 1 request bit in HSW_POWER_WELL_DRIVER (but not that of the misc IO
power well). This happens to not cause a problem due to the forced-on
request bits in the other request registers.

I've filed a bug about all this, but fixing that may take a while and
having this sanity check in place makes sense even for future firmware
versions.

At the same time also check the KVMR request bits. I haven't seen this
being altered, but we don't expect any request bits in here either, so
sanitize this register as well.

v2:
- Apply the workaround on SKL as well. I noticed the related failure
  from the CI report, later Patrik also reported seeing it on his
  machine.

CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459851965-6137-1-git-send-email-imre.deak@intel.com

The registers frobbed by vlv_init_display_clock_gating() libve inside
the disp2d power well, so frobbing them while the power well is down
results in unclaimed register access warning (and of course the values
won't stick). Let's do this setup after we know the power well is
enabled.

It's also worth noting that DSPCLK_GATE_D and CBR1_VLV lose their state
when the power well goes down, but fortunately the values we've been
writing are actually the reset defaults.

MI_ARB_VLV actually retains its value even if the power well was turned
off, we just can't access it while the power well is down.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94164Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460382992-28728-9-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

dev_priv is what the macro works hard to extract, pass it directly.

> sed 's/\([A-Z].*(dev_priv\)->dev)/\1)/g'

v2:
- Include all wrapper macros too (Chris)

v3:
- Include sed cmdline (Chris)

v4:
- Break long line
- Rebase

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460016485-8089-1-git-send-email-joonas.lahtinen@linux.intel.com

The BXT display connections have DSI transcoders A and C that can be
muxed to any pipe, not unlike the eDP transcoder. Add the notion of DSI
transcoders.

The "normal" transcoders A, B and C are not used with BXT DSI, so care
must be taken to avoid accessing those registers with DSI transcoders in
the hardware state readout, modeset, and generally everywhere.

v2: addressing comments by Ville:
 - rename the dsi get config function to hsw_get_dsi_transcoder_state
 - rebase onto the higher level split of pipe/transcoder functions
 - use more has_dsi_encoder as we can now because of the above,
   with no need to look at the transcoder so much
 - rename IS_DSI_TRANSCODER to transcoder_is_dsi
 - use the above a bit more instead of comparing to < TRANSCODER_EDP
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/299740536b7941e31b2744f3ce34f7afe936a771.1458313400.git.jani.nikula@intel.com

The DSI power domain was missing from BXT power well 1 definitions,
failing to get the power well for DSI transcoders. As pipe A is in the
same power well as DSI transcoders, the problem should only occur with
pipes B and C.

According to Ville, this is basically a nop since pw1 is under dmc
control. But given that we still have this stuff defined here, it's
clearly correct to include DSI here.

Cc: Ramalingam C <ramalingam.c@intel.com>
Cc: Deepak M <m.deepak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457463656-29357-1-git-send-email-jani.nikula@intel.com

In commit 1e657ad7 we moved the last step of firmware initialization to
skl_display_core_init(), where it will be run only during system resume,
but not during driver loading. Since this init step needs to be done
whenever we program the firmware fix this by moving the initialization
to the end of intel_csr_load_program().

While at it simplify a bit csr_load_work_fn().

This issue prevented DC5/6 transitions, this change will re-enable those.

v2:
- remove debugging left-over and redundant comment in csr_load_work_fn()

Fixes: 1e657ad7 ("drm/i915/gen9: Write dc state debugmask bits only once")
CC: Mika Kuoppala <mika.kuoppala@intel.com>
CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457121461-16729-1-git-send-email-imre.deak@intel.com

commit 09731280
Author: Imre Deak <imre.deak@intel.com>
Date:   Wed Feb 17 14:17:42 2016 +0200

    drm/i915: Add helper to get a display power ref if it was already enabled

left the rpm wakelock assertions unbalanced if CONFIG_PM was disabled as
intel_runtime_pm_get_if_in_use() would return true without incrementing
the local bookkeeping required for the assertions.

Fixes: 09731280 ("drm/i915: Add helper to get a display power ref if it was already enabled")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
CC: Mika Kuoppala <mika.kuoppala@intel.com>
CC: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456434628-22574-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NImre Deak <imre.deak@intel.com>
(cherry picked from commit 135dc79e)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

During system suspend we need to first disable power wells then
unitialize the display core. In case power well support is disabled we
did this in the wrong order, so fix this up.

Fixes: d314cd43 ("drm/i915: fix handling of the disable_power_well module option")
CC: stable@vger.kernel.org
CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456778945-5411-1-git-send-email-imre.deak@intel.com
(cherry picked from commit 2622d79b)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Disabling the DC states when it's already disabled is a valid scenario,
for example during HW state sanitization during driver loading and
resuming or when DC states are disabled via the i915.enable_dc or
disable_power_well option.

CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456778945-5411-4-git-send-email-imre.deak@intel.com

If power well support is disabled via the i915.disable_power_well module
option we should never enable DC states. Currently we would enable DC
states even in this case during system suspend, where we need to disable
all power wells regardless of the disable_power_well option.

CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456778945-5411-3-git-send-email-imre.deak@intel.com

We can simplify the conditions selecting the target DC state during
runtime by calculating the allowed DC states in advance during driver
loading. This also makes it easier to disable DC states depending on the
i915.disable_power_well module option, added in the next patch.

v2:
- Print a debug message if the requested max DC value was adjusted due
  to a platform limit. Also debug print the calculated mask value. (Patrik)

CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456778945-5411-2-git-send-email-imre.deak@intel.com

During system suspend we need to first disable power wells then
unitialize the display core. In case power well support is disabled we
did this in the wrong order, so fix this up.

Fixes: d314cd43 ("drm/i915: fix handling of the disable_power_well module option")
CC: stable@vger.kernel.org
CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456778945-5411-1-git-send-email-imre.deak@intel.com

commit 09731280
Author: Imre Deak <imre.deak@intel.com>
Date:   Wed Feb 17 14:17:42 2016 +0200

    drm/i915: Add helper to get a display power ref if it was already enabled

left the rpm wakelock assertions unbalanced if CONFIG_PM was disabled as
intel_runtime_pm_get_if_in_use() would return true without incrementing
the local bookkeeping required for the assertions.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
CC: Mika Kuoppala <mika.kuoppala@intel.com>
CC: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

commit 09731280
Author: Imre Deak <imre.deak@intel.com>
Date:   Wed Feb 17 14:17:42 2016 +0200

    drm/i915: Add helper to get a display power ref if it was already enabled

left the rpm wakelock assertions unbalanced if CONFIG_PM was disabled as
intel_runtime_pm_get_if_in_use() would return true without incrementing
the local bookkeeping required for the assertions.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
CC: Mika Kuoppala <mika.kuoppala@intel.com>
CC: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456434628-22574-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NImre Deak <imre.deak@intel.com>

Starting from BDW the DE_PIPE interrupts for pipe B and C belong to the
relevant display power well. So we should make sure we've finished
processing them before turning off the power well.

The pipe interrupts shouldn't really happen at this point anymore since
we've already shut down the planes/pipes/whatnot, but being a bit
paranoid shouldn't hurt.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455907651-16397-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

After we've told the irq code we don't want to handle display irqs
anymore, we must make sure any display irq handling already
kicked off has finished before we actually turn off the power well.

I wouldn't expect PIPESTAT based interrupts to occur anymore since
vblanks/page flips/gmbus/etc should all be quiescent at this point.
But at least hotplug interrupts could still occur. Hotplug
interrupts may also kick off the workqueue based hotplug processing,
but that code should take the required power domain references
itself, so there shouldn't be any need to synchronize with the
hotplug processing from the power well code.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455900112-15387-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

It has been observed that sometimes disabling the dc6 fails
and dc6 state pops back up, brief moment after disabling. This
has to be dmc save/restore timing issue or other bug in the
way dc states are handled.

Try to work around this issue as we don't have firmware fix
yet available. Verify that the value we wrote for the dmc sticks,
and also enforce it by rewriting it, if it didn't.

v2: Zero rereads on rewrite for extra paranoia (Imre)

Testcase: kms_flip/basic-flip-vs-dpms
References: https://bugs.freedesktop.org/show_bug.cgi?id=93768
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455811089-27884-1-git-send-email-mika.kuoppala@intel.com
(cherry picked from commit 779cb5d3)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

The DMC can incorrectly run off and allow DC states on it's own. We
don't know the root-cause for this yet but this patch makes it more
visible.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455808874-22089-2-git-send-email-mika.kuoppala@intel.com
(cherry picked from commit 832dba88)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

We have many places in the code where we check if a given display power
domain is enabled and if so access registers backed by this power
domain. We assumed that some modeset lock will prevent the power
reference from vanishing in the middle of the HW access, but this
assumption doesn't always hold. In such cases we get either the wakeref
not held, or an unclaimed register access error message. To fix this in
a future-proof way that's independent of other locks wrap any such
access with a get_ref_if_enabled()/put_ref() pair.

Kudos to Ville and Joonas for the ideas of this new interface.

v2:
- init the power_domains ptr when declaring it everywhere (Joonas)
v3:
- don't report the device to be powered if runtime PM is disabled

CC: Mika Kuoppala <mika.kuoppala@intel.com>
CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455711462-7442-1-git-send-email-imre.deak@intel.com
(cherry picked from commit 09731280)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

DMC debugmask bits should stick so no need to write them
everytime dc state is changed.

v2: Write after firmware has been successfully loaded (Ville)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455808874-22089-5-git-send-email-mika.kuoppala@intel.com

Cores need to be included into the debug mask. We don't exactly
know what it does but the spec says it must be enabled. So obey.

v2: Cores should be only set for BXT (Imre, Art)

Cc: Imre Deak <imre.deak@intel.com>
Cc: Runyan, Arthur J <arthur.j.runyan@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455877564-5128-1-git-send-email-mika.kuoppala@intel.com

It has been observed that sometimes disabling the dc6 fails
and dc6 state pops back up, brief moment after disabling. This
has to be dmc save/restore timing issue or other bug in the
way dc states are handled.

Try to work around this issue as we don't have firmware fix
yet available. Verify that the value we wrote for the dmc sticks,
and also enforce it by rewriting it, if it didn't.

v2: Zero rereads on rewrite for extra paranoia (Imre)

Testcase: kms_flip/basic-flip-vs-dpms
References: https://bugs.freedesktop.org/show_bug.cgi?id=93768
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455811089-27884-1-git-send-email-mika.kuoppala@intel.com

The DMC can incorrectly run off and allow DC states on it's own. We
don't know the root-cause for this yet but this patch makes it more
visible.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455808874-22089-2-git-send-email-mika.kuoppala@intel.com

We have many places in the code where we check if a given display power
domain is enabled and if so access registers backed by this power
domain. We assumed that some modeset lock will prevent the power
reference from vanishing in the middle of the HW access, but this
assumption doesn't always hold. In such cases we get either the wakeref
not held, or an unclaimed register access error message. To fix this in
a future-proof way that's independent of other locks wrap any such
access with a get_ref_if_enabled()/put_ref() pair.

Kudos to Ville and Joonas for the ideas of this new interface.

v2:
- init the power_domains ptr when declaring it everywhere (Joonas)
v3:
- don't report the device to be powered if runtime PM is disabled

CC: Mika Kuoppala <mika.kuoppala@intel.com>
CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455711462-7442-1-git-send-email-imre.deak@intel.com

Move the ddi buffer translation programming to occur from the encoder
.pre_enable() hook, for just the ddi port we are enabling. Previously
we used to reprogram the translations for all ddi ports during
init and during power well enabling.

v2: s/intel_prepare_ddi_buffers/intel_prepare_ddi_buffer/ (Daniel)
    Resolve conflicts due to  dev_priv->atomic_cdclk_freq
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When adding IS_KABYLAKE definition I didn't included the
DC states related because I was planing to include them
with the patch that fixes DMC firmware loading, but I
forgot them.

Meanwhile this runtime pm code changed a lot for
Skylake.

Well, I didn't expect that this would crash the machine
and I just noticed now that Sarah warned me our driver
wasn't working. Thanks Sarah.

Michel had found the main error first and his
fix had better details on the history and got
merged already:

commit 16fbc291
Author: Michel Thierry <michel.thierry@intel.com>
Date:   Wed Jan 6 12:08:36 2016 +0000

    drm/i915/kbl: Enable PW1 and Misc I/O power wells

This one is a follow-up adding the other remaining
missing pieces.

v2: Rebased on top of Michel's patch as explained above.

Cc: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452214179-22361-1-git-send-email-rodrigo.vivi@intel.com

My kbl stopped working because of this.

Fixes regression from
commit 2f693e28
Author: Damien Lespiau <damien.lespiau@intel.com>
Date:   Wed Nov 4 19:24:12 2015 +0200
    drm/i915: Make turning on/off PW1 and Misc I/O part of the init/fini
    sequences

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452082116-16770-1-git-send-email-michel.thierry@intel.comReviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

pm_runtime_{use,dont_use}_autosuspend() controls whether the device's
sysfs power/autosuspend_delay_ms file is writeable or returns -EIO on
access to user space. Since

commit 25b181b4
Author: Imre Deak <imre.deak@intel.com>
Date:   Thu Dec 17 13:44:56 2015 +0200

  drm/i915: get a permanent RPM reference on platforms w/o RPM support

this sysfs file is writeable also on platforms without RPM support, but
userspace (at least IGT) depends on this file being unchangable to
determine whether the device supports runtime PM at all. So restore the
old behavior.

This gets rid of igt/pm_rpm failures on old platforms without RPM
support, where the test should be skipped.

Testcase: igt/pm_rpm/basic-rte
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450371873-878-1-git-send-email-imre.deak@intel.com

In some cases we want to check whether we hold an RPM wakelock reference
for the whole duration of a sequence. To achieve this add a new RPM
atomic sequence counter that we increment any time the wakelock refcount
drops to zero.  Check whether the sequence number stays the same during
the atomic section and that we hold the wakelock at the beginning of the
section.

Motivated by Chris.

v2-v3:
- unchanged
v4:
- swap the order of atomic_read() and assert_rpm_wakelock_held() in
  assert_rpm_atomic_begin() to avoid race
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-10-git-send-email-imre.deak@intel.com

With this change we have the corresponding wake lock checks in both the
rpm get and put functions.

v2-v3:
- unchanged
v4:
- keep the corresponding check in the get helper (Chris)
v5:
- add a note to the commit message that with this change we have the
  checks both in the rpm get and put functions (Joonas)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-9-git-send-email-imre.deak@intel.com

Atm, we assert that the device is not suspended until the point when the
device is truly put to a suspended state. This is fine, but we can catch
more problems if we check that RPM refcount is non-zero. After that one
drops to zero we shouldn't access the device any more, even if the actual
device suspend may be delayed. Change assert_rpm_wakelock_held()
accordingly to check for a non-zero RPM refcount in addition to the
current device-not-suspended check.

For the new asserts to work we need to annotate every place explicitly in
the code where we expect that the device is powered. The places where we
only assume this, but may not hold an RPM reference:
- driver load
  We assume the device to be powered until we enable RPM. Make this
  explicit by taking an RPM reference around the load function.
- system and runtime sudpend/resume handlers
  These handlers are called when the RPM reference becomes 0 and know the
  exact point after which the device can get powered off. Disable the
  RPM-reference-held check for their duration.
- the IRQ, hangcheck and RPS work handlers
  These handlers are flushed in the system/runtime suspend handler
  before the device is powered off, so it's guaranteed that they won't
  run while the device is powered off even though they don't hold any
  RPM reference. Disable the RPM-reference-held check for their duration.

In all these cases we still check that the device is not suspended.
These explicit annotations also have the positive side effect of
documenting our assumptions better.

This caught additional WARNs from the atomic modeset path, those should
be fixed separately.

v2:
- remove the redundant HAS_RUNTIME_PM check (moved to patch 1) (Ville)
v3:
- use a new dedicated RPM wakelock refcount to also catch cases where
  our own RPM get/put functions were not called (Chris)
- assert also that the new RPM wakelock refcount is 0 in the RPM
  suspend handler (Chris)
- change the assert error message to be more meaningful (Chris)
- prevent false assert errors and check that the RPM wakelock is 0 in
  the RPM resume handler too
- prevent false assert errors in the hangcheck work too
- add a device not suspended assert check to the hangcheck work
v4:
- rename disable/enable_rpm_asserts to disable/enable_rpm_wakeref_asserts
  and wakelock_count to wakeref_count
- disable the wakeref asserts in the IRQ handlers and RPS work too
- update/clarify commit message
v5:
- mark places we plan to change to use proper RPM refcounting with
  separate DISABLE/ENABLE_RPM_WAKEREF_ASSERTS aliases (Chris)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1450227139-13471-1-git-send-email-imre.deak@intel.com

Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-7-git-send-email-imre.deak@intel.com

We don't really need to check this flag in the get/put/assert helpers,
as on platforms without RPM support we won't ever enable RPM. That means
pm.suspend will be always false and the assert will be always true.

Do this to simplify the code and to let us extend the RPM asserts to all
platforms for a better coverage.

Motivated by Ville.

v2-v3:
- unchanged
v4:
- remove the HAS_RUNTIME_PM check from intel_runtime_pm_enable() too
  made possible by the previous two patches
v5:
- rebased on the previous new patch in the series that keeps
  HAS_RUNTIME_PM() in intel_runtime_pm_enable() with a permanent
  reference taken there
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450352931-16498-1-git-send-email-imre.deak@intel.com

Currently we disable RPM functionality on platforms that doesn't support
this by not putting/getting the RPM reference we receive from the RPM
core during driver loading/unloading respectively. This is somewhat
obscure, so make it more explicit by keeping a reference dedicated for
this particular purpose whenever the driver is loaded. This makes it
possible to remove the HAS_RUNTIME_PM() special casing from every other
places in the next patch.

v2:
- fix intel_runtime_pm_get vs. intel_runtime_pm_put in
  intel_power_domains_fini()
v3:
- take only a low level RPM reference so the ref tracking asserts
  continue to work (Ville)
- update the commit message
- move the patch earlier for bisectability
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450352696-16135-1-git-send-email-imre.deak@intel.com

We can make the RPM dependency on RC6 explcit in the code by taking an
actual RPM reference, instead of avoiding to drop the initial one. This
will also enable us to remove the HAS_RUNTIME_PM special casing from
more places in the next patch.

v2:
- fixed typo in commit message (Joonas)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-4-git-send-email-imre.deak@intel.com

Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-2-git-send-email-imre.deak@intel.com

Currently the gmbus code uses intel_aux_display_runtime_get/put in an
effort to make sure the hardware is powered up sufficiently for gmbus.
That function only takes the runtime PM reference which on VLV/CHV/BXT
is not enough. We need the disp2d/pipe-a well on VLV/CHV and power well
2 on BXT. So add a new power domnain for gmbus and kill off the now
unused intel_aux_display_runtime_get/put. And change
intel_hdmi_set_edid() to use the gmbus power domain too since that's all
we need there.

Also toss in a BUILD_BUG_ON() to catch problems if we run out of
bits for power domains. We're already really close to the limit...

[Patrik: Add gmbus string to debugfs output]
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>
[Cherry-picked from drm-intel-next-queued f0ab43e6 (Imre)]
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448643329-18675-3-git-send-email-imre.deak@intel.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

BXT power well support is not yet stable.  Starting with patch

        commit 9f836f90
        Author: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
        Date:   Mon Nov 16 16:20:01 2015 +0100

            drm/i915/gen9: Turn DC handling into a power well

DPMS off operations may actually cause the entire system to powerdown or
reboot.  Disable power well support for now until Broxton gets fixes
similar to what we have for SKL.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
References: http://lists.freedesktop.org/archives/intel-gfx/2015-November/081037.htmlSigned-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448990818-11005-1-git-send-email-matthew.d.roper@intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

We have serious dangling else bugs waiting to happen in our for_each_
style macros with ifs. Consider, for example,

 #define for_each_power_domain(domain, mask)                         \
         for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++) \
                 if ((1 << (domain)) & (mask))

If this is used in context:

	if (condition)
		for_each_power_domain(domain, mask);
	else
		foo();

foo() will be called for each domain *not* in mask, if condition holds,
and not at all if condition doesn't hold.

Fix this by reversing the conditions in the macros, and adding an else
branch for the "for each" block, so that other if/else blocks can't
interfere. Provide a "for_each_if" helper macro to make it easier to get
this right.

v2: move for_each_if to drmP.h in a separate patch.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448392916-2281-2-git-send-email-jani.nikula@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we experience a refcounting failure in a power domain/well (unref'ing at
least one too many times), log the name of the offending domain or well.
Signed-off-by: NDaniel Stone <daniels@collabora.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448034934-11926-2-git-send-email-daniels@collabora.com