During module load, if we fail to initialise the rings, we abort the
load reporting EIO. However during resume, even though we report EIO as
we fail to reinitialize the ringbuffers, the resume continues and the
device is restored - albeit in a non-functional state. As we cannot
execute any commands on the GPU, it is effectively wedged, mark it so.

As we now preserve the ringbuffers across resume, this should prevent
UXA from falling into the trap of repeatedly sending invalid
batchbuffers and dropping all further rendering into /dev/null.
Reported-and-tested-by: NJiri Kosina <jkosina@suse.cz>
References: https://bugs.freedesktop.org/show_bug.cgi?id=76554Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NOscar Mateo <oscar.mateo@intel.com>
[danvet: Drop unused error, spotted by Oscar.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Unfortunately this requires a drm-wide change, and I didn't see a sane
way around that. Luckily it's fairly simple, we just need to inline
the respective get_irq implementation from either drm_pci.c or
drm_platform.c.

With that we can now also remove drm_dev_to_irq from drm_irq.c.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The dev->struct_mutex locking in drm_irq.c only protects
dev->irq_enabled. Which isn't really much at all and only prevents
especially nasty ums userspace from concurrently installing the
interrupt handling a few times. Or at least trying.

There are tons of unlocked readers of dev->irqs_enabled in the vblank
wait code (and by extension also in the pageflip code since that uses
the same vblank timestamp engine).

Real modesetting drivers should ensure that nothing can go haywire
with a sane setup teardown sequence. So we only really need this for
the drm_control ioctl, everywhere else this will just paper over
nastiness.

Note that drm/i915 is a bit specially due to the gem+ums combination.
So there we also need to properly protect the entervt and leavevt
ioctls. But it's definitely saner to do everything in one go than to
drop the lock in-between.

Finally there's the gpu reset code in drm/i915. That one's just race
(concurrent userspace calls to for vblank waits of pageflips could
spuriously fail). So wrap it up in with a nice comment since fixing
this is more involved.

v2: Rebase and fix commit message (Thierry)
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

During resume the intel hda audio driver depends on the i915 driver
reinitializing the audio power domain. Since the order of calling the
i915 resume handler wrt. that of the audio driver is not guaranteed,
move the power domain reinitialization step to the resume_early
handler. This is guaranteed to run before the resume handler of any
other driver.

The power domain initialization in turn requires us to enable the i915
pci device first, so move that part earlier too.

Accordingly disabling of the i915 pci device should happen after the
audio suspend handler ran. So move the disabling later from the i915
resume handler to the resume_late handler.

v2:
- move intel_uncore_sanitize/early_sanitize earlier too, so they don't
  get reordered wrt. intel_power_domains_init_hw()

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76152Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Cc: stable@vger.kernel.org
[danvet: Add cc: stable and loud comments that this is just a hack.]
[danvet: Fix "Should it be static?" sparse warning reported by Wu
Fengguang's kbuilder.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This sould be enough.

v2: BDW should also run hsw_runtime_resume (Ben).
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that PC8 is part of runtime PM, the check is useless.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just because I have a SNB machine and I can easily test it.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We're adding runtime suspend support to more platforms, so organize
the code in a way that all a new platform needs to do is to add its
own gen-specific functions. Also rename the i915_ functions to intel_
to make it clear that it's the top level one, not something that just
runs on i915 platforms.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Remove the rest of the references to drm_i915_private_t. No functional
changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
[danvet: Drop hunk in i915_cmd_parser.c]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

After we removed all the intermediate abstractions, we can rename
these functions to just hsw_{en,dis}able_pc8.

v2: - Rebase.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We already get runtime PM references, and PC8 is now part of runtime
PM, so this is enough.

v2: - Rebase.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently, when our driver becomes idle for i915.pc8_timeout (default:
5s) we enable PC8, so we save some power, but not everything we can.
Then, while PC8 is enabled, if we stay idle for more
autosuspend_delay_ms (default: 10s) we'll enter runtime PM and put the
graphics device in D3 state, saving even more power. The two features
are separate things with increasing levels of power savings, but if we
disable PC8 we'll never get into D3.

While from the modularity point of view it would be nice to keep these
features as separate, we have reasons to merge them:
 - We are not aware of anybody wanting a "PC8 without D3" environment.
 - If we keep both features as separate, we'll have to to test both
   PC8 and PC8+D3 code paths. We're already having a major pain to
   make QA do automated testing of just one thing, testing both paths
   will cost even more.
 - Only Haswell+ supports PC8, so if we want to add runtime PM support
   to, for example, IVB, we'll have to copy some code from the PC8
   feature to runtime PM, so merging both features as a single thing
   will make it easier for enabling runtime PM on other platforms.

This patch only does the very basic steps required to have PC8 and
runtime PM merged on a single feature: the next patches will take care
of cleaning up everything.

v2: - Rebase.
v3: - Rebase.
    - Fully remove the deprecated i915 params since Daniel doesn't
      consider them as part of the ABI.
v4: - Rebase.
    - Fix typo in the commit message.
v5: - Rebase, again.
    - Add a huge comment explaining the different forcewake usage
      (Chris, Daniel).
    - Use open-coded forcewake functions (Daniel).
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we regularly defer the forcewake dance to a timer func, it is
likely to fire after we disable the device during suspend. This
generates an oops as we detect inconsistency in the hardware state. So
before suspend, we want to complete the outstanding dance and generally
sanitize the registers before handing back to the BIOS.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BDW is no longer flagged as preliminary hw, but without
i915.preliminary_hw_support module param set the logs are filled with
WARNs about it.

Just make semaphores off the BDW per-chip default for now.

CC: Ben Widawsky <ben@bwidawsk.net>
Reported-by: NSebastien Dufour <sebastien.dufour@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For example if we get bug reports with similar error states and
suspend count is always 1, that might lead the Sherlocks to
right general direction.
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just to be sure...
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This got lost when we shuffled around our internal branch and
GEN7_FEATURES macro. There were no HW changes to support FBC, so we just
need to set the flag.

v2: Don't allow FBC for any pipe but A on platforms with DDI. (Paulo)

Cc: Daisy Sun <daisy.sun@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The power domains framework is internal to the i915 driver, so pass
drm_i915_private instead of drm_device to its functions.

Also remove a dangling intel_set_power_well() declaration.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

pci_get_class(class, from) drops the refcount for 'from', so the
extra pci_dev_put we do on it will result in a use after free bug
starting with the WARN below.

Regression introduced in

commit 6a9c4b35
Author: Rui Guo <firemeteor@users.sourceforge.net>
Date:   Wed Jun 19 21:10:23 2013 +0800

    drm/i915: Fix PCH detect with multiple ISA bridges in VM

[  164.338460] WARNING: CPU: 1 PID: 2094 at include/linux/kref.h:47 klist_next+0xae/0x110()
[  164.347731] CPU: 1 PID: 2094 Comm: modprobe Tainted: G           O 3.13.0-imre+ #354
[  164.356468] Hardware name: Intel Corp. VALLEYVIEW B0 PLATFORM/NOTEBOOK, BIOS BYTICRB1.X64.0062.R70.1310112051 10/11/2013
[  164.368796] Call Trace:
[  164.371609]  [<ffffffff816a32a6>] dump_stack+0x4e/0x7a
[  164.377447]  [<ffffffff8104f75d>] warn_slowpath_common+0x7d/0xa0
[  164.384238]  [<ffffffff8104f83a>] warn_slowpath_null+0x1a/0x20
[  164.390851]  [<ffffffff8169aeae>] klist_next+0xae/0x110
[  164.396777]  [<ffffffff8130a110>] ? pci_do_find_bus+0x70/0x70
[  164.403286]  [<ffffffff813cb4a9>] bus_find_device+0x89/0xc0
[  164.409719]  [<ffffffff8130a373>] pci_get_dev_by_id+0x63/0xa0
[  164.416238]  [<ffffffff8130a4e4>] pci_get_class+0x44/0x50
[  164.422433]  [<ffffffffa034821f>] intel_dsm_detect+0x16f/0x1f0 [i915]
[  164.429801]  [<ffffffffa03482ae>] intel_register_dsm_handler+0xe/0x10 [i915]
[  164.437831]  [<ffffffffa02d30fe>] i915_driver_load+0xafe/0xf30 [i915]
[  164.445126]  [<ffffffff8158a150>] ? intel_alloc_coherent+0x110/0x110
[  164.452340]  [<ffffffffa0148c07>] drm_dev_register+0xc7/0x150 [drm]
[  164.459462]  [<ffffffffa014b23f>] drm_get_pci_dev+0x11f/0x1f0 [drm]
[  164.466554]  [<ffffffff816abb81>] ? _raw_spin_unlock_irqrestore+0x51/0x70
[  164.474287]  [<ffffffffa02cf7a6>] i915_pci_probe+0x56/0x60 [i915]
[  164.481185]  [<ffffffff8130a028>] pci_device_probe+0x78/0xf0
[  164.487603]  [<ffffffff813cd495>] driver_probe_device+0x155/0x350
[  164.494505]  [<ffffffff813cd74e>] __driver_attach+0x6e/0xa0
[  164.500826]  [<ffffffff813cd6e0>] ? __device_attach+0x50/0x50
[  164.507333]  [<ffffffff813cb2be>] bus_for_each_dev+0x6e/0xc0
[  164.513752]  [<ffffffff813ccefe>] driver_attach+0x1e/0x20
[  164.519870]  [<ffffffff813cc958>] bus_add_driver+0x138/0x260
[  164.526289]  [<ffffffffa0188000>] ? 0xffffffffa0187fff
[  164.532116]  [<ffffffff813cde78>] driver_register+0x98/0xe0
[  164.538558]  [<ffffffffa0188000>] ? 0xffffffffa0187fff
[  164.544389]  [<ffffffff813087b0>] __pci_register_driver+0x60/0x70
[  164.551336]  [<ffffffffa014b37d>] drm_pci_init+0x6d/0x120 [drm]
[  164.558040]  [<ffffffffa0188000>] ? 0xffffffffa0187fff
[  164.563928]  [<ffffffffa018806a>] i915_init+0x6a/0x6c [i915]
[  164.570363]  [<ffffffff810002da>] do_one_initcall+0xaa/0x160
[  164.576783]  [<ffffffff8103b140>] ? set_memory_nx+0x40/0x50
[  164.583100]  [<ffffffff810ce7f5>] load_module+0x1fb5/0x2550
[  164.589410]  [<ffffffff810caab0>] ? store_uevent+0x40/0x40
[  164.595628]  [<ffffffff810cee7d>] SyS_init_module+0xed/0x100
[  164.602048]  [<ffffffff816b3c52>] system_call_fastpath+0x16/0x1b

v2: simplify the loop further (Chris)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reported-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65652
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74161Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

A check of rps/rc6 state after i915_reset determined that the ring
MAX_IDLE registers were returned to their hardware defaults and that
the GEN6_PMIMR register was set to mask all interrupts. This change
restores those values to their pre-reset states by re-initializing
rps/rc6 in i915_reset. A full re-initialization was opted for versus
a targeted set of restore operations for simplicity and maintain-
ability. Note that the re-initialization is not done for Ironlake,
due to a past comment that it causes problems.

Also updated the rps initialization sequence to preserve existing
min/max values in the case of a re-init. We assume the values were
validated upon being set and do not do further range checking. The
debugfs interface for changing min/max was updated with range
checking to ensure this condition (already present in sysfs
interface).

v2: fix rps logging to output hw_max and hw_min, not rps.max_delay
    and rps.min_delay which don't strictly represent hardware limits.
    Add igt testcase to signed-off-by section.

Testcase: igt/pm_rps/reset
Signed-off-by: NJeff McGee <jeff.mcgee@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

RFCv2: Reorganize array indexing so that full offsets can be used as
is. It makes grepping for registers in i915_reg.h much easier. Also
move offset arrays to intel_device_info.

v1: Fixed offsets for VLV, proper eDP handling

v2: Fixed BCLRPAT, PIPESRC, PIPECONF and DSP* macros.

v3: Added EDP pipe comment, removed redundant offset arrays for
    MSA_MISC and DDI_FUNC_CTL.

v4: Rename patch and report object size increase.

v5: Change location of commas, add PIPE_EDP into enum pipe

v6: Insert PIPE_EDP_OFFSET into pipe offset array

v7: Set I915_MAX_PIPES back to 3, change more registers accessors
    to use the new macros, get rid of _PIPE_INC and add dev_priv
    as a parameter where required by the new macros.

Upcoming hardware will not have the various display pipe register
ranges evenly spaced in memory. Change register address calculations
into array lookups.

Tested on SNB, VLV, IVB, Gen2 and HSW w/eDP.

I left the UMS cruft untouched.

Size differences:
   text    data     bss     dec     hex filename
 596431    4634      56  601121   92c21 i915.ko (new)
 593199    4634      56  597889   91f81 i915.ko (old)
Signed-off-by: NAntti Koskipaa <antti.koskipaa@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With 20+ module parameters, I think referring to them via a struct
improves clarity over just having a bunch of globals. While at it, move
the parameter initialization and definitions into a new file
i915_params.c to reduce clutter in i915_drv.c.

Apart from the ill-named i915_enable_rc6, i915_enable_fbc and
i915_enable_ppgtt parameters, for which we lose the "i915_" prefix
internally, the module parameters now look the same both on the kernel
command line and in code. For example, "i915.modeset".

The downsides of the change are losing static on a couple of variables
and not having the initialization and module_param_named() right next to
each other. On the other hand, all module parameters are now defined in
one place at i915_params.c. Plus you can do this to find all module
parameter references:

$ git grep "i915\." -- drivers/gpu/drm/i915

v2:
- move the definitions into a new file
- s/i915_params/i915/
- make i915_try_reset i915.reset, for consistency
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's unused, and nowadays specifying unknown parameters no longer
prevents modules from being loaded.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we're doing the reset handling a bit late, and we're doing
it both in the driver load code and on resume. This makes it unusable
for e.g. resetting the panel power sequence state like Paulo wants to.

Instead of adding yet another single-use callback shuffle things
around:
- Output handling code is responsible to reset/init all state on its
  own at driver load time.
- We call the reset functions much earlier, before we start using any
  of the modeset code.

Compared to Paulo's new ->resume callback the only difference in
placement is that ->reset is still called without dev->struct_mutex
held. Which is imo a feature.

v2: Rebase on top of the now merge dinq.

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

The opregion notification for runtime suspend is currently D1, not D3.
Signed-off-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It ought to work ok in 3.14.  We have some fun stuff coming after that,
but all the basics are in place now and seem relatively stable.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Acked by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A couple patches in the upcoming rework of semaphores will break if
semaphores are toggled by the user at various times. Since the code
cleanups there seem to be an overall win, and toggling semaphores at
runtime is not a terribly useful thing to do, simply make the module
parameter read-only.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As with processes which run on the CPU, the goal of multiple VMs is to
provide process isolation. Specific to GEN, there is also the ability to
map more objects per process (2GB each instead of 2Gb-2k total).

For the most part, all the pipes have been laid, and all we need to do
is remove asserts and actually start changing address spaces with the
context switch. Since prior to this we've converted the setting of the
page tables to a streamed version, this is quite easy.

One important thing to point out (since it'd been hotly contested) is
that with this patch, every context created will have it's own address
space (provided the HW can do it).

v2: Disable BDW on rebase

NOTE: I tried to make this commit as small as possible. I needed one
place where I could "turn everything on" and that is here. It could be
split into finer commits, but I didn't really see much point.

Cc: Eric Anholt <eric@anholt.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Only the two intel drivers need this and they can easily check for
working agp support in their driver ->load callbacks.

This is the only reason why agp initialization could fail, so allows
us to rip out a bit of error handling code in the next patch.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Noticed while reviewing a patch and couldn't resist the OCD.
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So we'll get a fault when someone tries to access the mmap, then we'll
wake up from D3.

v2: - Rebase
v3: - Use gtt active/inactive

Testcase: igt/pm_pc8/gem-mmap-gtt
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
[danvet: Add comment + WARN as discussed with Paulo on irc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The hangcheck function requires the hardware to be working, and if
we're suspending we're going to put the HW in D3 state.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

All mobile gen2 and gen3 chipsets should have FBC1, and the code
should now handle them all. So just set has_fbc=true for all such
chipsets.

Note that fbc is still disabled by default for now.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we are actually setting the device to the D3 state, we should
issue the notification.

The opregion spec says we should send the message before the adapter
is about to be placed in a lower power state, and after the adapter is
placed in a higher power state.

Jani originally wrote a similar patch for PC8, but then we discovered
that we were not really changing the PCI D states when
enabling/disabling PC8, so we had to postpone his patch.

v2: - Improve commit message, explaining the expected state.

v3: - Rebase.

Cc: Jani Nikula <jani.nikula@intel.com>
Credits-to: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com> (v2)
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds the initial infrastructure to allow a Runtime PM
implementation that sets the device to its D3 state. The patch just
adds the necessary callbacks and the initial infrastructure.

We still don't have any platform that actually uses this
infrastructure, we still don't call get/put in all the places we need
to, and we don't have any function to save/restore the state of the
registers. This is not a problem since no platform uses the code added
by this patch. We have a few people simultaneously working on runtime
PM, so this initial code could help everybody make their plans.

V2: - Move some functions to intel_pm.c
    - Remove useless pm_runtime_allow() call at init
    - Remove useless pm_runtime_mark_last_busy() call at get
    - Use pm_runtime_get_sync() instead of 2 calls
    - Add a WARN to check if we're really awake

V3: - Rebase.

V4: - Don't need to call pci_{save,restore}_state and
      pci_set_power_sate, since they're already called by the PCI
      layer
    - Remove wrong pm_runtime_enable() call at init_runtime_pm
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We call intel_modeset_setup_hw_state() along two paths, driver
load/resume and after a lid event notification. During initialisation of
the driver, it is imperative that we reset the config state. This
correctly sets up the initial connector statuses and prepares the
hardware for a thorough probing. However, during a lid event, we only
want to undo the damage caused by the bios by resetting our last known
mode. In this cirumstance, we do not want to clobber our desired state.

In order to try and keep sanity between the config state and our own
tracking, do the drm_mode_config_reset() first along the load/resume
paths before reading out the hw state and apply any definite known
corrections.

v2: "As discussed on irc I don't think we should force the connector
state to anything here: Imo connector->status should reflect what we
believe to be the true output connection state, whereas connector->encoder
reflects whether this connector is wired up to a pipe. And since we no
longer reject modeset on disconnected connectors and never nuked the pipe
if the connector gets disconnected there's no reason for that - such policy
is userspace's job.

This regression has been introduced in

commit 2e938892
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Oct 11 20:08:24 2012 +0200

    drm/i915/crt: explicitly set up HOTPLUG_BITS on resume"
so sayeth Daniel.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: stable@vger.kernel.org (v3.8 and later)
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is just a theoretical issue, but we need to do this to prevent the
WARN in pipe_from_connector at suspend time.

This regression has been introduce in

commit 7bd688cd
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Fri Nov 8 16:48:56 2013 +0200

    drm/i915: handle backlight through chip specific functions

https://bugs.freedesktop.org/show_bug.cgi?id=71978Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This would have never worked.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Oops, makes testing early boot failures in i915.ko a bit more pain, so
let's fix it.

v2: We already have a bit of static storage to track this (Chris).
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At least since SNB (perhaps even earlier) even the desktop parts
should have FBC.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>