The current check doesn't handle the case where we don't steal an
encoder, but keep it on the current connector. If we repurpose
disable_conflicting_encoders to do the checking, we just have
to reject the ones that conflict.

Changes since v1:
- Return early with empty encoder_mask, drm_for_each_connector
  requires connection_mutex held.
Changes since v2:
- Add comments for the loops.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Testcase: kms_setmode.invalid-clone-single-crtc-stealing
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456996662-8704-6-git-send-email-maarten.lankhorst@linux.intel.com

Instead of failing with -EINVAL when conflicting encoders are found,
the legacy set_config will disable other connectors when encoders
conflict.

With the previous commit this becomes a lot easier to implement.
set_config only adds connectors to the state that are modified,
and because of the previous commit that calls add_affected_connectors
only on set->crtc it means any connector not part of the modeset can
be stolen from. We disable the connector in that case, and possibly
the crtc if required.

Atomic modeset itself still doesn't allow encoder stealing, the results
would be too unpredictable.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456996662-8704-5-git-send-email-maarten.lankhorst@linux.intel.com

There's no need to have a separate function to get the crtc
which is stolen, this can already be found when actually
stealing the encoder.

drm_for_each_connector already checks for connection_mutex, so
use that macro now.

Changes since v1:
- Do not check for NULL crtc in connector_state,
  this may happen when a crtc is disabled and its encoder stolen.
- Because of this, use connector->state->crtc instead of conn_state->crtc.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456996662-8704-4-git-send-email-maarten.lankhorst@linux.intel.com

Minor cleanup, connector and connector_state are always non-NULL here.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456303053-28806-3-git-send-email-maarten.lankhorst@linux.intel.com

With the addition of crtc_state->connector_mask other connectors from
different crtc's aren't needed any more to determine if a crtc has
connectors, so only call add_affected_connectors on the target crtc.
This allows a cleanup to first remove all current connectors, then
add all set->connectors to the target crtc.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1456303053-28806-2-git-send-email-maarten.lankhorst@linux.intel.com

This allows iteration over encoders without requiring connection_mutex.

Changes since v1:
- Add a set_best_encoder helper function and update encoder_mask inside
  it.
Changes since v2:
- Relax the WARN_ON(!crtc), with explanation.
- Call set_best_encoder when connector is moved between crtc's.
- Add some paranoia to steal_encoder to prevent accidentally setting
  best_encoder to NULL.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/56AA200A.6070501@linux.intel.com

While we steal the encoder away from the connector the connector may
be updated to use a different encoder.

Without this change if 2 connectors swap encoders one of them will
end up without a crtc.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1452160762-30487-5-git-send-email-maarten.lankhorst@linux.intel.com

The Rockchip driver cannot use drm_atomic_helper_wait_for_vblanks()
because it has hardware counters for neither vblanks nor scanlines.

In order to simplify re-implementing the functionality for this driver,
export the framebuffer_changed() helper so it can be reused.
Signed-off-by: NJohn Keeping <john@metanate.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When no console framebuffer is enabled, the default plane state is
defined by plane reset function. If driver uses generic helper, then
rotation property is set to zero. This is not a valid value for that
enum. This patch sets default rotation value to DRM_ROTATE_0.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453192008-13283-1-git-send-email-m.szyprowski@samsung.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

One of the two local variables old_crtc_state is redundantly defined in the
function disable_outputs().  It has only a scope partway through the block
for_each_connector_in_state.  So, let's remove it and use the one which
has the scope within the function disable_outputs().
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453088195-2564-1-git-send-email-gnuiyl@gmail.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that connector_mask is reliable there's no need for this
function any more.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451908400-25147-6-git-send-email-maarten.lankhorst@linux.intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want this for consistency with existing page_flip semantics.

Since this spurred quite a discussion on IRC also document why we
reject event generation when the pipe is off: It's not that it's hard
to implement, but userspace has a track recording which proves that it's
way too easy to accidentally abuse and cause havoc. We want to make
sure userspace doesn't get away with that.

v2: Somehow thought we do reject events already, but that code only
existed in my imagination ... Also suggestions from Thierry.

Cc: Daniel Stone <daniels@collabora.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449564561-3896-4-git-send-email-daniel.vetter@ffwll.ch

This is useful for drivers that subclass connector_state, like tegra.

Changes since v1:
- Docbook updates.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451908400-25147-2-git-send-email-maarten.lankhorst@linux.intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just a remnant from an old iteration of this patch that I've forgotten
to remove: We only need the encoder to figure out whether it has been
reassigned in this update already or not to figure out whether there's
a conflict or not.
Reported-by: NThierry Reding <thierry.reding@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449564561-3896-2-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Show a sensible name for the plane in debug mesages. The driver
may supply its own name, otherwise the core genrates the name
("plane-0", "plane-1" etc.).

v2: kstrdup() the name passed by the caller (Jani)
v3: Generate a default name if the driver doesn't supply one
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449592922-5545-7-git-send-email-ville.syrjala@linux.intel.com

Show a sensible name for the crtc in debug mesages. The driver may
supply its own name, otherwise the core genrates the name
("crtc-0", "crtc-1" etc.).

v2: kstrdup() the name passed by the caller (Jani)
v3: Generate a default name if the driver doesn't supply one
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449592922-5545-6-git-send-email-ville.syrjala@linux.intel.com

They have pretty kerneldoc already, but better to link to that in
one of the overview sections.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-26-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

Currently we have 4 helper libraries (probe, crtc, plane & atomic)
that all use the same helper vtables. And that's by necessity since we
don't want to litter the core structs with one ops pointer per helper
library. Also often the reuse the same hooks (like atomic does, to
facilite conversion from existing drivers using crtc and plane
helpers).

Given all that it doesn't make sense to put the docs for these next to
specific helpers. Instead extract them into a new header file and
section in the docbook, and add references to them everywhere.

Unfortunately kernel-doc complains when an include directive doesn't
find anything (and it does by dumping crap into the output file). We
have to remove the now empty includes to avoid that, instead of leaving
them in for future proofing.

v2: More OCD in ordering functions.

v3: Spelling plus collate copyright headers properly.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-4-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

This can happen when we run out of encoders for a multi-crtc modeset,
or also when userspace is silly and tries to clone multiple connectors
that need the same encoder on the same crtc.
Reported-and-Tested-and-Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449136154-11588-1-git-send-email-daniel.vetter@ffwll.ch

Provide subsystem-level suspend and resume helpers that can be used to
implement suspend/resume on atomic mode-setting enabled drivers.

v2: simplify locking, enhance kerneldoc comments
v3: pass lock acquisition context by parameter, improve kerneldoc
v4: - remove redundant code (already provided by atomic helpers)
      (Maarten Lankhorst)
    - move backoff dance from drm_modeset_lock_all_ctx() into suspend
      helper (Daniel Vetter)
v5: handle potential EDEADLK from drm_atomic_helper_duplicate_state()
    and drm_atomic_helper_disable_all() (Daniel Vetter)
Signed-off-by: NThierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449075005-13937-2-git-send-email-thierry.reding@gmail.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add drm_atomic_helper_disable_planes_on_crtc() for disabling all
planes associated with the given CRTC. This can be used for instance
in the CRTC helper disable callback to disable all planes before
shutting down the display pipeline.

v2:
- Address Daniels review comments [1]
  - Do atomic_begin() and atomic_flush() always if they are defined and
    atomic knob is set
  - update kerneldoc
- Put drm_atomic_helper_disable_planes_on_crtc() after
  drm_atomic_helper_commit_planes_on_crtc() in drm_atomic_helper.c
  to have functions in the same order as in drm_atomic_helper.h
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448633641-6486-1-git-send-email-jsarha@ti.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The drm_property_unreference_blob() function tests whether its argument
is NULL and then returns immediately.
Thus the tests around the calls are not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Link: http://patchwork.freedesktop.org/patch/msgid/563C8B3E.405@users.sourceforge.netSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was totally lost when I originally created the atomic helpers.

We probably should also check possible_clones in the helpers, but
since the legacy ones didn't do that this is for a separate patch.
Reported-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Stone <daniels@collabora.com>
Reviewed-by: NDaniel Stone <daniels@collabora.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@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447868808-10266-1-git-send-email-daniel.vetter@ffwll.ch

Properly double the hdisplay/vdisplay timings that we use as the primary
plane size with stereo doubled modes. Otherwise the modeset gets
rejected on machines where the primary plane must be fullscreen, and on
the rest only the first eye would get a visible plane.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org #v3.19+
Fixes: 042652ed ("drm/atomic-helper: implementatations for legacy interfaces")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447686157-29607-1-git-send-email-ville.syrjala@linux.intel.com
Testcase: igt/kms_3d
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

legacy_cursor_update was being set in restore_fbdev_mode_atomic which was
probably unintended. Fix this by only setting it in the function that needs it.

This oversight was introduced in

commit bbb1e524
Author: Rob Clark <robdclark@gmail.com>
Date:   Tue Aug 25 15:35:58 2015 -0400

    drm/fb-helper: atomic restore_fbdev_mode()...
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[Jani: checkpatch fix]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-2-git-send-email-maarten.lankhorst@ubuntu.com

When converting the mode hdisplay/vdisplay to primary plane src
coordinates we need to take into account the current plane
rotation.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1444930802-8515-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add support for using atomic code-paths for restore_fbdev_mode().
Signed-off-by: NRob Clark <robdclark@gmail.com>
[danvet: Bikeshed comments slightly.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since commit "drm/atomic-helper: Add option to update planes only on
active crtc" the drm_atomic_helper_commit_planes() function accepts an
active_only argument to skip updating planes when the associated CRTC is
inactive. Planes being disabled on an active CRTC are incorrectly
considered as associated with an inactive CRTC and are thus skipped,
preventing any plane disabling update from reaching drivers.

Fix it by checking the state of the CRTC stored in the old plane state
for planes being disabled.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This function can be used to duplicate an atomic state object. This is
useful for example to implement suspend/resume, where the state before
suspend can be saved and restored upon resume.

v2: move locking to caller, be more explicit about prerequisites
v3: explicitly pass lock acquisition context, improve kerneldoc
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Requested by Laurent.

Note that this uses the new markdown support which will only land in
kernel 4.4 (for the code snippet).

v2: A few spelling fixes I spotted myself.

v3: Big reword for commit_planes() kerneldoc based on a text from
Laurent.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thierry Reding <treding@nvidia.com> (v1 on irc)
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

With drivers supporting runtime pm it's generally not a good idea to
touch the hardware when it's off. Add an option to the commit_planes
helper to support this case.

Note that the helpers already add all planes on a crtc when a modeset
happens, hence plane updates will not be lost if drivers set this to
true.

v2: Check for NULL state->crtc before chasing the pointer. Also check
both old and new crtc if there's a switch. Finally just outright
disallow switching crtcs for a plane if the plane is in active use, on
most hardware that doesn't make sense.

v3: Since commit_planes(active_only = true) is for enabling things
only after all the crtc are on we should only look at the new crtc to
decide whether to call the plane hooks - if the current CRTC isn't on
then skip. If the old crtc (when moving a plane) went down then the
plane should have been disabled as part of the pipe shutdown work
already. For which there's currently no helper really unfortunately.
Also move the check for wether a plane gets a new CRTC assigned while
still in active use out of this patch.

v4: Rebase over exynos changes.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Tested-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This removes the need to separately track fb changes i915.
That will be done as a separate commit, however.

Changes since v1:
- Add dri-devel to cc.
- Fix a check in intel's prepare and cleanup fb to take rotation
  into account.
Changes since v2:
- Split out i915 changes to a separate commit.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
[danvet: Squash in msm fixup from Maarten.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Without the () the markup and more important hyperlinking wont happen.

v2: Also fix nearby type Laurent spotted.

v3: Actually git add. Argh!
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Instead of using the legacy VBLANK API, use the new KMS API. This is
part of an effort to convert all existing users so that the KMS API can
be changed to properly use per-CRTC data.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch fixes null pointer access incurred when
encoder driver didn't set its own mode_fixup callback.

mode_fixup callback shoudn't be called if the callback
of drm_encoder_helper_funcs is NULL.

Changelog v2:
- change it to else if
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Even though 'compatability' has a dedicated entry in the Wiktionary,
it's listed as 'Mispelling of compatibility'. Fix it.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> for the atomic_helper.c
Signed-off-by: NJiri Kosina <jkosina@suse.com>

We've had a few issues with atomic where subtle bugs in the encoder
picking logic lead to accidental self-stealing of the encoder,
resulting in a NULL connector_state->crtc in update_connector_routing
and subsequent.

Linus applied some duct-tape for an mst regression in

commit 27667f47
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed Jul 29 22:18:16 2015 -0700

    i915: temporary fix for DP MST docking station NULL pointer dereference

But that was incomplete (the code will still oops when debuggin is
enabled) and mangled the state even further. So instead WARN and bail
out as the more future-proof option.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

With legacy helpers all the routing was already set up when calling
best_encoder and so could be inspected. But with atomic it's staged,
hence we need a new atomic compliant callback for drivers which need
to inspect the requested state and can't just decided the best encoder
statically.

This is needed to fix up i915 dp mst where we need to pick the right
encoder depending upon the requested CRTC for the connector.

v2: Don't forget to amend the kerneldoc

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Ted Ts'o reports that his Lenovo T540p ThinkPad crashes at boot if
attached to the docking station.  This is a regression that he was able
to bisect to commit 8c7b5ccb: "drm/i915: Use atomic helpers for
computing changed flags:"

The reason seems to be the new call to drm_atomic_helper_check_modeset()
added to intel_modeset_compute_config(), which in turn calls
update_connector_routing(), and somehow ends up picking a NULL crtc for
the connector state, causing the subsequent drm_crtc_index() to OOPS.

Daniel Vetter says that the fundamental issue seems to be confusion in
the encoder selection, and this isn't the right fix, but while he chases
down the proper fix, this at least avoids the NULL pointer dereference
and makes Ted's docking station work again.
Reported-bisected-and-tested-by: NTheodore Ts'o <tytso@mit.edu>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Mani Nikula <jani.nikula@linux.intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>