Since BIOS RC 1.4 it would enable CDCLK PLL during BIOS S3 resume, then
driver needs to set CDCLK to avoid display corruption if DPLL0 enabled.

References: https://bugs.freedesktop.org/show_bug.cgi?id=91697Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NCooper Chiou <cooper.chiou@intel.com>
Reviewed-by: NWei Shun Chang <wei.shun.chang@intel.com>
Tested-by: NGary Wang <gary.c.wang@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Gavin Hindman <gavin.hindman@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Xiong Y Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NGary Wang <gary.c.wang@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

v2: fix one error found by checkpath.pl
v3: Add one ignored break for switch-case. DDI-E hotplug
    function doesn't work after updating drm-intel tree,
    I checked the code and found this missing which isn't
    the root cause for broke DDI-E hp.  The broken
    DDI-E hp function is fixed by "Adding DDI_E power
    well domain".
Signed-off-by: NXiong Zhang <xiong.y.zhang@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Tested-by: NTimo Aaltonen <timo.aaltonen@canonical.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

The gtt.stolen_size field is of type size_t, and so should be printed
using %zu to avoid build warnings on either 32-bit and 64-bit builds.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

SKL-Y can now use the same programming for all VccIO values after an
adjustment to I_boost.  SKL-U DP table adjustments.

1. Remove SKL Y 0.95V from "SKL H and S" columns in all tables. The
   other SKL Y column removes the "0.85V VccIO" so it now applies to all
   voltages.

2. DP table changes SKL U 400mV+0db dword 0 value from 2016h to 201Bh.

3. DP table changes SKL U 600mv+0db dword 0 value from 2016h to 201Bh.

4. DP table increases I_boost to level 3 for SKL Y 400mv+9.5db.

v2: Fix compilation warnings as pointed by Paulo.

Reference: Graphics Spec Change r97962
Cc: Arthur Runyan <arthur.j.runyan@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[Jani: reformatted commit message for shorter lines.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

VBT version 196 increased the size of common_child_dev_config. The
parser code assumed that the size of this structure would not change.

The modified code now copies the amount needed based on the VBT version,
and emits a debug message if the VBT version is unknown (too new); since
the struct config block won't shrink in newer versions it should be
harmless to copy the maximum known size in such cases, so that's what we
do, but emitting the warning is probably sensible anyway.

In the longer run it might make sense to modify the parser code to use a
version/feature mapping, rather than hardcoding things like this, but
for now the variants are fairly manageable.

This fixes a regression introduced in

commit 75067dde
Author: Antti Koskipaa <antti.koskipaa@linux.intel.com>
Date:   Fri Jul 10 14:10:55 2015 +0300

    drm/i915: Per-DDI I_boost override

since that commit changed the child device config size without updating
the checks and memcpy.

v2: Stricter size checks

v3 by Jani:
- Keep the checks strict, and warnigns verbose, but keep going anyway.
- Take care to copy the max amount of child device config we can.
- Fix the messages.
Signed-off-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This patch fixes the bug that SKL SKUs before B0 might return
HBR2 as supported even though it is not supposed to be enabled
on such platforms.

v2: optimize if else condition (Jani)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
[Jani: minor whitespace fix.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

commit 75067dde
Author: Antti Koskipaa <antti.koskipaa@linux.intel.com>
Date:   Fri Jul 10 14:10:55 2015 +0300

    drm/i915: Per-DDI I_boost override

increased size of union child_device_config without taking into account
the size check in parse_sdvo_device_mapping(). Switch the function over
to using the legacy struct only.

Fixes: 75067dde ("drm/i915: Per-DDI I_boost override")
Cc: Antti Koskipaa <antti.koskipaa@linux.intel.com>
Cc: David Weinehall <david.weinehall@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This patch removes TP3 support on CHV since there is no support
for HBR2 on this platform.

v2: rename the function to indicate it checks source rates (Jani)
v3: update comment to indicate TP3 dependency on HBR2 supported
    hardware (Jani)

Cc: stable@vger.kernel.org # v4.1+
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
[Jani: fixed a couple of checkpatch warnings.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This patch removes 5.4Gbps from supported link rate for CHV since
it is not supported in it.

v2: change the ordering for better readability (Ville)

Cc: stable@vger.kernel.org # v4.1+
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This reverts
commit fe51bfb9.
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Thu Mar 12 17:10:38 2015 +0200

CHV does not support intermediate frequencies so reverting the
patch that added it in the first place

Cc: stable@vger.kernel.org # v4.1+
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This reverts

commit 047fe6e6
Author: David Weinehall <david.weinehall@linux.intel.com>
Date:   Tue Aug 4 16:55:52 2015 +0300

    drm/i915: Allow parsing of variable size child device entries from VBT

That commit is not valid for v4.2, however it will be valid for v4.3. It
was simply queued too early.

The referenced regressing commit is just fine until the size of struct
common_child_dev_config changes, and that won't happen until
v4.3. Indeed, the expected size checks here rely on the increased size
of the struct, breaking new platforms.

Fixes: 047fe6e6 ("drm/i915: Allow parsing of variable size child device entries from VBT")
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Weinehall <david.weinehall@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Everytime we use the logical context with execlists it becomes dirty (as
the hardware will write the new register values afterwards, as well as
the GPU state that will be used). We need to then flag the context as
dirty everytime since after a swap-out/swap-in cycle the dirty flag will
be cleared, and a further swap-out cycle will then loose the most recent
GPU state.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

An OEM may request increased I_boost beyond the recommended values
by specifying an I_boost value to be applied to all swing entries for
a port. These override values are specified in VBT.

v2: rebase and remove unused iboost_bit variable

Issue: VIZ-5676
Signed-off-by: NAntti Koskipaa <antti.koskipaa@linux.intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is currently conflicting documentation on which steppings the
workaround is needed, up to C vs. forever. However there is post-C
stepping hardware that doesn't report port presence on DDI A, leading to
black screen on eDP. Assume the strap isn't connected, and try to enable
DDI A on these machines. (We'll still check the VBT for the info in DDI
init.)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

DP spec requires the checksum of the last block read to be written
when replying to TEST_EDID_READ. This patch fixes the current code
to do the same.

v2: removed loop for jumping blocks and performed direct addition
as recommended by Daniel
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Reviewed-by: NSonika Jindal <sonika.jindal@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Prevent leaking the if scoping by containing the WA_REG
macro inside its own scope.
Reported-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
[danvet: Appease checkpatch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we encounter an allocation failure during ppggt creation (trivial
even with 16Gib+ RAM!), we need to remove the dead context from the
fpriv->context_idr along with the references.

gem_exec_ctx: page allocation failure: order:0, mode:0x8004
CPU: 3 PID: 27272 Comm: gem_exec_ctx Tainted: G        W       4.2.0-rc5+ #37
 0000000000000000 ffff880086ff7a78 ffffffff816b947a ffff88041ed90038
 0000000000008004 ffff880086ff7b08 ffffffff8114b1a5 ffff880086ff7ac8
 ffffffff8108d848 0000000000000000 ffffffff81ce84b8 0000000000000000
Call Trace:
 [<ffffffff816b947a>] dump_stack+0x45/0x57
 [<ffffffff8114b1a5>] warn_alloc_failed+0xd5/0x120
 [<ffffffff8108d848>] ? __wake_up+0x48/0x60
 [<ffffffff8114e0ed>] __alloc_pages_nodemask+0x73d/0x8e0
 [<ffffffffc0472238>] ? i915_gem_execbuffer2+0x148/0x240 [i915]
 [<ffffffffc0474240>] __setup_page_dma+0x30/0x110 [i915]
 [<ffffffffc0477f61>] gen8_ppgtt_init+0x31/0x2f0 [i915]
 [<ffffffffc04785e0>] i915_ppgtt_init+0x30/0x80 [i915]
 [<ffffffffc0478928>] i915_ppgtt_create+0x48/0xc0 [i915]
 [<ffffffffc046c9c2>] i915_gem_create_context+0x1c2/0x390 [i915]
 [<ffffffffc046d9cb>] i915_gem_context_create_ioctl+0x5b/0xa0 [i915]

leading to an oops in i915_gem_context_close. Also note that this
benchmark should not be running out of memory in the first place...

Testcase: igt/benchmark/gem_exec_ctx -b create # ppgtt >= 2
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The IOMMU for Intel graphics has historically had many issues resulting
in random GPU hangs. Lets include its status when capturing the GPU hang
error state for post-mortem analysis.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If idle to active bit is set, the rest of the fields
in CSQ are not valid.

Bail out early if this is the case in order to prevent
rest of the loop inspecting stale values.

This was found by Bspec/code inspection. Doesn't seem to fix any of
the known issues.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
[danvet: Add note about how this was found.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is no correspondent Aux channel for DDI-E.

So we need to rely on VBT to let us know witch one
is being used instead.

v2: Removing some trailing spaces and giving proper
credit to Xiong that added a nice way to avoid port
conflicts by setting supports_dp = 0 when using
equivalent aux for DDI-E.

Credits-to: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NXiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

DDI-E and DDI-A share 4 the same DDI-A lanes.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NXiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I started digging this when I noticed that the BDW code was just
reserving 1mb by coincidence since it was reading reserved fields.
Then I noticed we didn't have any values set for SNB and earlier, and
that the HSW sizes were wrong. After that, I noticed that the reserved
area has a specific start, and may not exactly end where the stolen
memory ends. I also noticed the base pointer can be zero. So I decided
to just write a single patch fixing everything instead of 20 patches
that would be much harder to review.

This patch may solve random stolen memory corruption/problems on
almost all platforms. Notice that since this is always dealing with
the top of the stolen memory, the problems are not so easy to
reproduce - especially since FBC is still disabled by default.

One of the major differences of this patch is that we now look at both
the size and base address. By only looking at the size we were
assuming that the reserved area was always at the very top of
stolen, which is not always true.

After we merge the patch series that allows user space to allocate
stolen memory we'll be able to write IGT tests that maybe catch the
bugs fixed by this patch.

v2:
  - s/BIOS reserved/stolen reserved/g (Chris)
  - Don't DRM_ERROR if we can't do anything about it (Chris)
  - Improve debug messages (Chris).
  - Use the gen7 version instead of gen6 on HSW. Tom found some
    documentation problems, so I think with gen7 we're on the safer
    side (Tom).
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This register needs to be updated with masked writes.

This was found by code inspection and comparison with Bspec and
doesn't seem to fix any known issue.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
[danvet: Add note about impact.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add WaDisableSbeCacheDispatchPortSharing:skl

Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we encounter frequent problems with dp aux channel
communications, we end up spamming the dmesg with the
exact similar trace and status.

Inject a new backtrace only if we have new information
to share as otherwise we flush out all other important
stuff.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

-EDEADLK has special meaning in atomic, but get_fence may call
i915_find_fence_reg which can return -EDEADLK.

This has special meaning in the atomic world, so convert the error
to -EBUSY for this case.

Changes since v1:
- Add comment in the code.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The rest will be a noop anyway, since without modeset there will be
no updated dplls and no modeset state to update.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There are no more users, byebye!
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that everything's atomic, checking encoder->base.crtc is enough.
This function doesn't have the locks to dereference crtc->state, but
stealing an encoder bound to any crtc is probably enough reason to warn.

Changes since v1:
- Commit message.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

connectors_active will be removed, so just calculate this instead.

Changes since v1:
- Look for the right pointer in intel_sanitize_encoder.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is now done completely atomically.
Keep connectors_active for now, but make it mirror crtc_state->active.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of allocating pipe_config on the stack use the old
crtc_state, it's only going to freed from this point on.

All crtc' are now only checked once during modeset,
because false positives can happen with encoders after
dpms changes and to limit the amount of errors for 1 failure.

Changes since v1:
- crtc_state -> old_crtc_state
- state -> old_state
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Connectors are updated atomically now, so the only interaction
with the encoder is through base.crtc.

If it's NULL the encoder's not part of any crtc, and if it's
not NULL then active should be equal to crtc_state->active.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is handled by the atomic core now, no need to check this for ourself.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Right now dpms callbacks can still fiddle with the connector state,
but it can only turn connectors off.

This is remediated by only checking crtc->state->active when the
connector is active, and ignore crtc->state->active when the
connector is off.

connectors_active is no longer checked, and will be removed later
in this series together with dpms.

Another check for !encoder->crtc is performed by check_encoder_state
too, so it can be removed.

Changes since v1:
- Add commit message.
- rename state to old_state.
- Move deletion of mst_port check to mst patch.
Changes since v2:
- Fix a null pointer dereference on MST now hw readout is fixed.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fully remove the MST connector from the atomic state, and remove the
early returns in check_*_state for MST connectors.

With atomic the state can be made consistent all the time.

Thanks to Sivakumar Thulasimani for the idea of using
drm_atomic_helper_set_config.

Changes since v1:
- Remove the MST check in intel_connector_check_state too.
Changes since v2:
- Use drm_atomic_helper_set_config.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

First step in removing dpms and validating atomic state.

There can still be a mismatch in the connector state because the dpms
callbacks are still used, but this can not happen immediately after a modeset.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Set connectors_changed to force a modeset if the panel fitter's force
enabled on eDP.

Changes since v1:
- Use connectors_changed instead of active_changed because it's a
  routing update.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is based on the upstream commit 5ac1c4bc and amended
for v4.2 to make sure it works as intended.

Repeated calls to begin_crtc_commit can cause warnings like this:
[  169.127746] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616
[  169.127835] in_atomic(): 0, irqs_disabled(): 1, pid: 1947, name: kms_flip
[  169.127840] 3 locks held by kms_flip/1947:
[  169.127843]  #0:  (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffff814774bc>] __drm_modeset_lock_all+0x9c/0x130
[  169.127860]  #1:  (crtc_ww_class_acquire){+.+.+.}, at: [<ffffffff814774cd>] __drm_modeset_lock_all+0xad/0x130
[  169.127870]  #2:  (crtc_ww_class_mutex){+.+.+.}, at: [<ffffffff81477178>] drm_modeset_lock+0x38/0x110
[  169.127879] irq event stamp: 665690
[  169.127882] hardirqs last  enabled at (665689): [<ffffffff817ffdb5>] _raw_spin_unlock_irqrestore+0x55/0x70
[  169.127889] hardirqs last disabled at (665690): [<ffffffffc0197a23>] intel_pipe_update_start+0x113/0x5c0 [i915]
[  169.127936] softirqs last  enabled at (665470): [<ffffffff8108a766>] __do_softirq+0x236/0x650
[  169.127942] softirqs last disabled at (665465): [<ffffffff8108ae75>] irq_exit+0xc5/0xd0
[  169.127951] CPU: 1 PID: 1947 Comm: kms_flip Not tainted 4.1.0-rc4-patser+ #4039
[  169.127954] Hardware name: LENOVO 2349AV8/2349AV8, BIOS G1ETA5WW (2.65 ) 04/15/2014
[  169.127957]  ffff8800c49036f0 ffff8800cde5fa28 ffffffff817f6907 0000000080000001
[  169.127964]  0000000000000000 ffff8800cde5fa58 ffffffff810aebed 0000000000000046
[  169.127970]  ffffffff81c5d518 0000000000000268 0000000000000000 ffff8800cde5fa88
[  169.127981] Call Trace:
[  169.127992]  [<ffffffff817f6907>] dump_stack+0x4f/0x7b
[  169.128001]  [<ffffffff810aebed>] ___might_sleep+0x16d/0x270
[  169.128008]  [<ffffffff810aed38>] __might_sleep+0x48/0x90
[  169.128017]  [<ffffffff817fc359>] mutex_lock_nested+0x29/0x410
[  169.128073]  [<ffffffffc01635f0>] ? vgpu_write64+0x220/0x220 [i915]
[  169.128138]  [<ffffffffc017fddf>] ? ironlake_update_primary_plane+0x2ff/0x410 [i915]
[  169.128198]  [<ffffffffc0190e75>] intel_frontbuffer_flush+0x25/0x70 [i915]
[  169.128253]  [<ffffffffc01831ac>] intel_finish_crtc_commit+0x4c/0x180 [i915]
[  169.128279]  [<ffffffffc00784ac>] drm_atomic_helper_commit_planes+0x12c/0x240 [drm_kms_helper]
[  169.128338]  [<ffffffffc0184264>] __intel_set_mode+0x684/0x830 [i915]
[  169.128378]  [<ffffffffc018a84a>] intel_crtc_set_config+0x49a/0x620 [i915]
[  169.128385]  [<ffffffff817fdd39>] ? mutex_unlock+0x9/0x10
[  169.128391]  [<ffffffff81467b69>] drm_mode_set_config_internal+0x69/0x120
[  169.128398]  [<ffffffff8119b547>] ? might_fault+0x57/0xb0
[  169.128403]  [<ffffffff8146bf93>] drm_mode_setcrtc+0x253/0x620
[  169.128409]  [<ffffffff8145c600>] drm_ioctl+0x1a0/0x6a0
[  169.128415]  [<ffffffff810b3b41>] ? get_parent_ip+0x11/0x50
[  169.128424]  [<ffffffff811e9ab8>] do_vfs_ioctl+0x2f8/0x530
[  169.128429]  [<ffffffff810d0fcd>] ? trace_hardirqs_on+0xd/0x10
[  169.128435]  [<ffffffff812e7676>] ? selinux_file_ioctl+0x56/0x100
[  169.128439]  [<ffffffff811e9d71>] SyS_ioctl+0x81/0xa0
[  169.128445]  [<ffffffff81800697>] system_call_fastpath+0x12/0x6f

Solve it by using the newly introduced drm_atomic_helper_commit_planes_on_crtc.

The problem here was that the drm_atomic_helper_commit_planes() helper
we were using was basically designed to do

    begin_crtc_commit(crtc #1)
    begin_crtc_commit(crtc #2)
    ...
    commit all planes
    finish_crtc_commit(crtc #1)
    finish_crtc_commit(crtc #2)

The problem here is that since our hardware relies on vblank evasion,
our CRTC 'begin' function waits until we're out of the danger zone in
which register writes might wind up straddling the vblank, then disables
interrupts; our 'finish' function re-enables interrupts after the
registers have been written.  The expectation is that the operations between
'begin' and 'end' must be performed without sleeping (since interrupts
are disabled) and should happen as quickly as possible.  By clumping all
of the 'begin' calls together, we introducing a couple problems:
 * Subsequent 'begin' invocations might sleep (which is illegal)
 * The first 'begin' ensured that we were far enough from the vblank that
   we could write our registers safely and ensure they all fell within
   the same frame.  Adding extra delay waiting for subsequent CRTC's
   wasn't accounted for and could put us back into the 'danger zone' for
   CRTC #1.

This commit solves the problem by using a new helper that allows an
order of operations like:

   for each crtc {
        begin_crtc_commit(crtc)  // sleep (maybe), then disable interrupts
        commit planes for this specific CRTC
        end_crtc_commit(crtc)    // reenable interrupts
   }

so that sleeps will only be performed while interrupts are enabled and
we can be sure that registers for a CRTC will be written immediately
once we know we're in the safe zone.

The crtc->config->base.crtc update may seem unrelated, but the helper
will use it to obtain the crtc for the state. Without the update it
will dereference NULL and crash.

Changes since v1:
- Use Matt Roper's commit message.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=90398Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This should be much cleaner, with the same effects.

(cherry picked for v4.2 from commit fb9d6cf8)
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=90398Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>