These platforms should be fine now.

FBC can allow very significant power savings for screen-on idle
systems, but it is worth mentioning that a lot of people won't get
significant power savings by enabling this feature because they may
have something else preventing the system from getting into the
deepest sleep states. Examples may include a hungry wifi device or a
max_performance SATA link power management policy. You can check your
PC state residencies on the powertop "Idle stats" tab. I recommend
trying to run "sudo powertop --auto-tune" and then seeing if the
residencies improve.

Oh, and in case you - the person reading this commit message - found
this commit through git bisect, please do the following:
 - Check your dmesg and see if there are error messages mentioning
   underruns around the time your problem started happening.
 - Download intel-gpu-tools, compile it, and run:
   $ sudo ./tests/kms_frontbuffer_tracking --run-subtest '*fbc-*' 2>&1 | tee fbc.txt
   Then send us the fbc.txt file, especially if you get a failure.
   This will really maximize your chances of getting the bug fixed
   quickly.
 - Try to find a reliable way to reproduce the problem, and tell us.
 - Boot with drm.debug=0xe, reproduce the problem, then send us the
   dmesg file.

v2: Don't enable by default on SKL.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455655643-2535-1-git-send-email-paulo.r.zanoni@intel.com

This is a manual revert of

commit 7a10dfa6
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Apr 1 09:33:47 2014 +0200

    drm/i915: Add debug module option for VTd validation

as no users have appeared.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455621493-6865-2-git-send-email-jani.nikula@intel.com

We've given write permissions to dynamically change some module
parameters through /sys/module/i915/parameters although they only
support setting on module load. Fix the permissions.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455621493-6865-1-git-send-email-jani.nikula@intel.com

The bpp value which is used while calulating the txbyteclkhs values
should be wrt the pixel format value. Currently bpp is coming
from pipe config to calculate txbyteclkhs. Fix it in this patch.

V2: dsi_pixel_format_bpp is used to retrieve the bpp from pixel_format
	[Review: Jani]
Signed-off-by: Deepak M <m.deepak@intel.com>
Signed-off-by: Yogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Tested-by: Mika Kahola <mika.kahola@intel.com> # BYT
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455203007-10850-1-git-send-email-ramalingam.c@intel.com

DSP CLK_GATE registers are specific to BYT and CHT.
Avoid programming the same for BXT platform.

v2: Rebased on latest drm nightly branch.

v3: Fixed Jani's review comments
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455796166-13052-1-git-send-email-jani.nikula@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Spotted-by: Mika Kuoppala <mika.kuoppala@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93441
CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455719489-3008-1-git-send-email-imre.deak@intel.com

We have an open coded loop which tries to see if the encoder has any
connectors linked to it. Let's extract that to a helper similar to
intel_crtc_has_encoders().
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455737325-14777-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This is another step in removing legacy state.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455697119-31416-6-git-send-email-maarten.lankhorst@linux.intel.com

With the conversion to atomic only on/off are still supported.
The rest is mapped to one of those, and when enable is called
DPMS_ON should be true.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455697119-31416-5-git-send-email-maarten.lankhorst@linux.intel.com

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455697119-31416-4-git-send-email-maarten.lankhorst@linux.intel.com

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455697119-31416-3-git-send-email-maarten.lankhorst@linux.intel.com

Instead of restoring dpms and a flag for whether a temp fb is allocated duplicate
an atomic state before the new state is committed, and commit it the old state
in intel_release_load_detect_pipe.

Changes since v1:
- Use a real atomic state. (Ville)
Changes since v2:
- Do not preserve shared_dpll any more, no need to do so. (Ville)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455697119-31416-2-git-send-email-maarten.lankhorst@linux.intel.com

With a reliable frontbuffer tracking and all instability corner cases
on Haswell and Broadwell solved let's re-enabled PSR by default on
these platforms.

In case a new issue is found and PSR is the main suspect, please check
if i915.enable_psr=0 really makes your problem go away. If this is the case
PSR is the culprit so after that please check if i915.enable_psr=2
or i915.enable_psr=3 solves your issue and please let us know.
There are many panels out there and not all implementations apparently
work as we would expect.

In case you needed to force it on standby or disabled or in case of any
PSR related bug please report it at bugs.freedesktop.org.
In a bugzilla entry for PSR is desirable:
- dmesg (drm.debug=0xe)
- output of /sys/kernel/debug/dri/0/i915_edp_psr_status
- Platform information. Vendor, model, id, pci id.
- Graphical environment: Gnome, KDE, openbox, etc...
- Details how to reproduce.
- Also good if you could run PSR test cases of Intel-gpu-tools
- Please mention if forcing main link standby or main link off helps you.

There are Intel-gpu-tools test cases that can be helpful to
determine if PSR is working as expected:
kms_psr_sink_crc and kms_psr_frontbuffer_tracking.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455278893-1307-2-git-send-email-rodrigo.vivi@intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

With a reliable frontbuffer tracking and all instability corner cases
solved for this platform let's re-enabled PSR by default.

In case a new issue is found and PSR is the main suspect, please check
if i915.enable_psr=0 really makes your problem go away,
please report it at bugs.freedesktop.org.

In a bugzilla entry for PSR is desirable:
- dmesg (drm.debug=0xe)
- output of /sys/kernel/debug/dri/0/i915_edp_psr_status
- Platform information. Vendor, model, id, pci id.
- Graphical environment: Gnome, KDE, openbox, etc...
- Details how to reproduce.
- Also good if you could run PSR test cases of Intel-gpu-tools
- Please mention if forcing main link standby or main link off helps you.

There are Intel-gpu-tools test cases that can be helpful to
determine if PSR is working as expected:
 kms_psr_sink_crc and kms_psr_frontbuffer_tracking.

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

This will give us flexibility to enable PSR by default independently so
issues and corner cases in one platform won't affect others were we have
it working properly.

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

Otherwise a pde_shift big enough to overflow a u32 will be truncated before
assignment

Note: We never asked for ranges spanning a 4G boundary, so this issue
doesn't cause a real problem.
Signed-off-by: Alan Cox <alan@linux.intel.com>
[danvet: Add note why this isn't a real problem.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160217142043.4947.60447.stgit@localhost.localdomain

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-13-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-12-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-11-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-10-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.

While at it also add the missing reference around the HW access in
i915_interrupt_info().

v2:
- update the commit message mentioning that this also fixes the
  HW access in the interrupt info debugfs entry (Daniel)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-9-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-8-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93439
CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-7-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-6-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-5-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-4-git-send-email-imre.deak@intel.com

The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Revieved-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-3-git-send-email-imre.deak@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: Imre Deak <imre.deak@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455711462-7442-1-git-send-email-imre.deak@intel.com

userptr requires mmu-notifier for full unprivileged support. Most
systems have mmu-notifier support already enabled as a requirement for
virtualisation support, but we should make the option for i915 to take
advantage of mmu-notifiers explicit (and enable by default so that
regular userspace can take advantage of passing client memory to the
GPU.)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1452503961-14837-3-git-send-email-chris@chris-wilson.co.uk

Unfortunately i915 is still not fully atomic, and expects mode_config.mutex
to be held during modeset until we finally fix it.

This fixes the following WARN when resuming:

[  425.208983] ------------[ cut here ]------------
[  425.208990] WARNING: CPU: 0 PID: 6828 at drivers/gpu/drm/drm_edid.c:3555 drm_select_eld+0xa5/0xd0()
[  425.209015] Modules linked in: pl2303 usbserial snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic intel_powerclamp coretemp i915 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_hda_codec snd_hwdep lpc_ich snd_hda_core snd_pcm i2c_hid i2c_designware_platform i2c_designware_core r8169 mii sdhci_acpi sdhci mmc_core
[  425.209018] CPU: 0 PID: 6828 Comm: kworker/u4:5 Tainted: G     U  W       4.5.0-rc4-gfxbench+ #1
[  425.209020] Hardware name: \xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff \xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff/DN2820FYK, BIOS FYBYT10H.86A.0038.2014.0717.1455 07/17/2014
[  425.209027] Workqueue: events_unbound async_run_entry_fn
[  425.209032]  0000000000000000 ffff880072433958 ffffffff813f6b05 0000000000000000
[  425.209036]  ffffffff81aaef2d ffff880072433990 ffffffff81078291 ffff880036b933d8
[  425.209039]  ffff88006d528000 ffff88006d52b3d8 ffff88006d52b3d8 ffff88007315b6f8
[  425.209040] Call Trace:
[  425.209045]  [<ffffffff813f6b05>] dump_stack+0x67/0x92
[  425.209049]  [<ffffffff81078291>] warn_slowpath_common+0x81/0xc0
[  425.209052]  [<ffffffff81078385>] warn_slowpath_null+0x15/0x20
[  425.209054]  [<ffffffff8151e195>] drm_select_eld+0xa5/0xd0
[  425.209101]  [<ffffffffa01f34f4>] intel_audio_codec_enable+0x44/0x160 [i915]
[  425.209135]  [<ffffffffa023eac7>] intel_enable_hdmi_audio+0x87/0x90 [i915]
[  425.209169]  [<ffffffffa023eb5a>] g4x_enable_hdmi+0x8a/0xa0 [i915]
[  425.209202]  [<ffffffffa023f41b>] vlv_hdmi_pre_enable+0x1cb/0x240 [i915]
[  425.209236]  [<ffffffffa020edcf>] valleyview_crtc_enable+0x10f/0x290 [i915]
[  425.209270]  [<ffffffffa020ba49>] intel_atomic_commit+0x769/0x17a0 [i915]
[  425.209274]  [<ffffffff81526ad5>] ? drm_atomic_check_only+0x145/0x660
[  425.209276]  [<ffffffff81527022>] drm_atomic_commit+0x32/0x50
[  425.209310]  [<ffffffffa0215fa0>] intel_display_resume+0xa0/0x130 [i915]
[  425.209338]  [<ffffffffa018c1bb>] i915_drm_resume+0xcb/0x160 [i915]
[  425.209366]  [<ffffffffa018c272>] i915_pm_resume+0x22/0x30 [i915]
[  425.209370]  [<ffffffff8143d91e>] pci_pm_resume+0x6e/0xe0
[  425.209373]  [<ffffffff8143d8b0>] ? pci_pm_resume_noirq+0xa0/0xa0
[  425.209375]  [<ffffffff815409ae>] dpm_run_callback+0x6e/0x280
[  425.209378]  [<ffffffff815410b2>] device_resume+0x92/0x250
[  425.209380]  [<ffffffff81541288>] async_resume+0x18/0x40
[  425.209382]  [<ffffffff8109c7a5>] async_run_entry_fn+0x45/0x140
[  425.209386]  [<ffffffff81093293>] process_one_work+0x1e3/0x620
[  425.209388]  [<ffffffff810931f7>] ? process_one_work+0x147/0x620
[  425.209391]  [<ffffffff81093719>] worker_thread+0x49/0x490
[  425.209393]  [<ffffffff810936d0>] ? process_one_work+0x620/0x620
[  425.209396]  [<ffffffff81099e0a>] kthread+0xea/0x100
[  425.209400]  [<ffffffff81099d20>] ? kthread_create_on_node+0x1f0/0x1f0
[  425.209404]  [<ffffffff817ba03f>] ret_from_fork+0x3f/0x70
[  425.209407]  [<ffffffff81099d20>] ? kthread_create_on_node+0x1f0/0x1f0
[  425.209409] ---[ end trace d1b247107f34a8b2 ]---

Fixes: e2c8b870 ("drm/i915: Use atomic helpers for suspend, v2.")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455632862-18557-1-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The check for active_crtcs == 0 was performed by the callers, when changing
the patches I forgot to remove those hunks.

This resulted in skylake scalers still not having the correct cdclk to
calculate scaling when all crtc's were dpms off.

Fixes: 1a617b77 ("drm/i915: Keep track of the cdclk as if all crtc's were active.")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455614711-9045-1-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Instead of duplicating the functionality now that we no longer need
to preserve dpll state we can move to using the upstream suspend helper.

Changes since v1:
- Call hw readout with all mutexes held.
- Rework intel_display_suspend to only assign modeset_restore_state
  on success.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/56C2E686.5060803@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

This behavior of checking for a shmem backed GEM object was introduced here:
commit 4c914c0c
Author: Brad Volkin <bradley.d.volkin@intel.com>
Date:   Tue Feb 18 10:15:45 2014 -0800

    drm/i915: Refactor shmem pread setup

It is possible for an object to not be a shmem backed GEM object (for example
userptr objects). An example of how we hit this failure can be found through
copy_batch() in the command parser because we allocate a userptr object for the
batch which contains privileged instructions. Userptr calls
drm_gem_private_object_init() which explicitly sets the filp to none.

NOTE: I manually retyped this from a test machine. So I haven't even compiled
this exact patch.

v2: Use same logic as from a2a4f916c2f (Kristian, Dave Gordon)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kristian Høgsberg <krh@bitplanet.net>
Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Tested-by: Jordan Justen <jordan.l.justen@intel.com> (v1)
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455047053-2644-1-git-send-email-benjamin.widawsky@intel.com

Unknown parameters, especially structure padding, are expected to invoke
rejection with -EINVAL.

v2: similar issue exists for context-create

Testcase: igt/gem_ctx_create/invalid-pad
Testcase: igt/gem_ctx_bad_destroy/invalid-pad
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89602
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93999Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1454690759-31201-1-git-send-email-chris@chris-wilson.co.uk

intel_digital_port_connected() lacks one 'else'. There's no
actual harm in not having it since each branch has an unconditional
return, so it can't accidentally end up in taking two branches instead
of just the one. But let's be consistent and add the 'else' anyway.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455201868-31527-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

Looks like g4x hpd live status bits actually agree with the spec. At
least they do on the machine I have, and apparently on Nick Bowler's
g4x as well.

So gm45 may be the only platform where they don't agree. At least
that seems to be the case based on the (somewhat incomplete)
logs/dumps in [1], and Daniel has also tested this on his gm45
sometime in the past.

So let's change the bits to match the spec on g4x. That actually makes
the g4x bits identical to vlv/chv so we can just share the code
between those platforms, leaving gm45 as the special case.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=52361

Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Nick Bowler <nbowler@draconx.ca>
References: https://lists.freedesktop.org/archives/dri-devel/2016-February/100382.htmlReported-by: Nick Bowler <nbowler@draconx.ca>
Cc: stable@vger.kernel.org
Fixes: 237ed86c ("drm/i915: Check live status before reading edid")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455127145-20087-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Code does read-modify-write but the read was outside the lock.

It is fine since the caller holds struct mutex, but if we
correct this we open up the opportunity for decreasing the
mutex duration time since the call to ironlake_enable_drps
does not need it any longer since it is covered by the
mchdev_lock lock.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1455186452-13691-2-git-send-email-tvrtko.ursulin@linux.intel.com

It does not look like this code needs to wait atomically?

Higher in the call chain it calls the GEM API and I do
not see that the section is under any spin locks or such.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Alex Dai <yu.dai@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>

RPS lock must be taken before the struct_mutex to avoid
locking inversion. So stop grabbing it for the whole
powersave initialization and instead only take it during
the sections which need it.

Also, struct_mutex is not needed any more since dedicated
RPS lock was added in:

   commit 4fc688ce
   Author: Jesse Barnes <jbarnes@virtuousgeek.org>
   Date:   Fri Nov 2 11:14:01 2012 -0700

       drm/i915: protect RPS/RC6 related accesses (including PCU) with a new mutex

Based on prototype patch by Chris Wilson and a subsequent
mailing list discussion involving Ville, Imre, Chris and
Daniel.

v2: More details in the commit.

v3: Use drm_gem_object_unreference_unlocked. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

VMA creation and GEM list management need the big lock.

v2:

Mutex unlock ended on the wrong path somehow. (0-day, Julia Lawall)

Not to mention drm_gem_object_unreference was there in existing
code with no mutex held.

v3:

Some callers of i915_gem_object_create_stolen_for_preallocated
already hold the lock so move the mutex into the other caller
as well.

v4:

Changed to lockdep_assert_held. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>