smatch correctly warns:

	drivers/gpu/drm/drm_fb_helper.c:1960 drm_target_preferred() warn: should '1 << i' be a 64 bit type?
	drivers/gpu/drm/drm_fb_helper.c:2001 drm_target_preferred() warn: should '1 << i' be a 64 bit type?
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A drm driver that is implementing

      fb_debug_enter and fb_debug_leave

in struct fb_ops with drm fb helper functions

     drm_fb_helper_debug_enter and drm_fb_helper_debug_leave

must also implement the callback 'mode_set_base_atomic' in struct
drm_crtc_helper_funcs. See Documentation/DocBook/kgdb.tmpl.  The current
implementation will segfault when 'mode_set_base_atomic' is a NULL
pointer.

Before this patch at least the drm drivers armada, ast, qxl, udl and
virtio do not have a 'mode_set_base_atomic' implementation but using
drm_fb_helper_debug_(enter|leave). So these drivers may segfault when
callbacks fb_debug_(enter|leave) are called.

Avoid the issue by just checking for NULL pointers. So all drivers can
unconditionally implement fb_debug_(enter|leave) with the drm_fb_helper
functions. If callback 'mode_set_base_atomic' is not implemented, the
code in drm_fb_helper_debug_(enter|leave) does effectively nothing.
Signed-off-by: NStefan Christ <contact@stefanchrist.eu>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1479078208-25221-2-git-send-email-contact@stefanchrist.eu

The fbdev helper code keeps around two lists of connectors. One is the
list of all connectors it could use, and that list already holds
references for all the connectors. However the other list, or rather
lists, is the one actively being used. That list is tracked per-crtc
and currently doesn't hold any extra references. Let's grab those
extra references to avoid oopsing when the connector vanishes. The
list of all possible connectors should get updated when the hpd happens,
but the list of actively used connectors would not get updated until
the next time the fb-helper picks through the set of possible connectors.
And so we need to hang on to the connectors until that time.

Since we need to clean up in drm_fb_helper_crtc_free() as well,
let's pull the code to a common place. And while at it let's
pull in up the modeset->mode cleanup in there as well. The case
of modeset->fb is a bit less clear. I'm thinking we should probably
hold a reference to it, but for now I just slapped on a FIXME.

v2: Cleanup things drm_fb_helper_crtc_free() too (Chris)
v3: Don't leak modeset->connectors (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Cc: Carlos Santa <carlos.santa@intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: Carlos Santa <carlos.santa@intel.com> (v1)
Tested-by: Kirill A. Shutemov <kirill@shutemov.name> (v1)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97666Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1477492878-4990-1-git-send-email-ville.syrjala@linux.intel.com

We need to drop the connector references already taken when we
abort in the middle of drm_fb_helper_single_add_all_connectors()

Cc: stable@vger.kernel.org
Cc: Carlos Santa <carlos.santa@intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: NCarlos Santa <carlos.santa@intel.com>
Tested-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1477472755-15288-2-git-send-email-ville.syrjala@linux.intel.com

Since 4.7 kernel, we've seen the error messages like

 kernel: [TTM] Buffer eviction failed
 kernel: qxl 0000:00:02.0: object_init failed for (4026540032, 0x00000001)
 kernel: [drm:qxl_alloc_bo_reserved [qxl]] *ERROR* failed to allocate VRAM BO

on QXL when switching and accessing on VT.  The culprit was the
generic deferred_io code (qxl driver switched to it since 4.7).
There is a race between the dirty clip update and the call of
callback.

In drm_fb_helper_dirty(), the dirty clip is updated in the spinlock,
while it kicks off the update worker outside the spinlock.  Meanwhile
the update worker clears the dirty clip in the spinlock, too.  Thus,
when drm_fb_helper_dirty() is called concurrently, schedule_work() is
called after the clip is cleared in the first worker call.

This patch addresses it by validating the clip before calling the
dirty fb callback.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98322
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1003298
Fixes: eaa434de ('drm/fb-helper: Add fb_deferred_io support')
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
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/20161020150530.5787-1-tiwai@suse.de

Now that all drivers have been converted over to the per-plane rotation
property, we can just nuke the global rotation property.

v2: Rebase due to BIT(),__builtin_ffs() & co.
    Deal with superfluous code shuffling
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1477077768-4274-4-git-send-email-ville.syrjala@linux.intel.com

Not all planes on the system may support the same rotations/reflections,
so make it possible to create a separate property for each plane.
This way userspace gets told exactly which rotations/reflections are
possible for each plane.

v2: Add drm_plane_create_rotation_property() helper
v3: Drop the BIT(), __builtin_ffs(x) - 1,
    Moar WARNs for bad parameters
    Deal with superfluous code shuffling
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474907460-10717-4-git-send-email-ville.syrjala@linux.intel.com

The current fbdev emulation does not allow to push back changes in
width, height or depth to KMS, hence reject any changes with an
error. This makes sure that fbdev ioctl's fail properly and user
space does not assume that changes succeeded.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161011231504.17688-1-stefan@agner.ch

drm_atomic_state has a complicated single owner model that tracks the
single reference from allocation through to destruction on another
thread - or perhaps on a local error path. We can simplify this tracking
by using reference counting (at a cost of a few more atomics). This is
even more beneficial when the lifetime of the state becomes more
convoluted than being passed to a single worker thread for the commit.

v2: Double check !intel atomic_commit functions for missing gets
v3: Update kerneldocs
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161014121833.439-27-chris@chris-wilson.co.uk

drm/drm_fb_helper.c:2306:12: warning: symbol 'drm_fb_helper_modinit' was not declared. Should it be static?

While at it, move the lefover static inline to the right place.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <seanpaul@chromium.org>
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/1474292035-15695-4-git-send-email-ville.syrjala@linux.intel.com

I figured I might as well go ocd and make them booleans and rename the
locked version too.

v2: Review from Noralf.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Cc: Noralf Trønnes <noralf@tronnes.org>
Fixes: cfe63423 ("drm/fb-helper: Add drm_fb_helper_set_suspend_unlocked()")
Acked-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160823152727.31788-1-daniel.vetter@ffwll.ch

This adds a function that also takes the console lock before calling
fb_set_suspend() in contrast to drm_fb_helper_set_suspend() which is
a plain wrapper around fb_set_suspend().
Resume is run asynchronously using a worker if the console lock is
already taken. This is modelled after the i915 driver.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1471953246-29602-1-git-send-email-noralf@tronnes.org

This reverts commit:

  fa7d81bb ("drm/fb-helper: Reduce READ_ONCE(master) to lockless_dereference")

As Peter explained:

  [...] lockless_dereference() is _stronger_ than READ_ONCE(), not weaker.

  [...]

  Also, clue is in the name: 'dereference', you don't actually dereference
  the pointer here, only load it.

My next patch breaks the compile without this revert, because it assumes
you want to deference and thus also need the struct type visible (which
it isn't here), so revert it.
Tested-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1470909022-687-1-git-send-email-johannes@sipsolutions.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

These are the leftovers I could only track down using keep_warnings =
True. For some of them we might want to update our style guide on how
to reference structures and constants, not sure ...

Cc: Markus Heiser <markus.heiser@darmarit.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-1-git-send-email-daniel.vetter@ffwll.ch

Everyone who uses the fbdev emulation helpers doesn't need to include
fb.h directly. Remove it.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-3-git-send-email-daniel.vetter@ffwll.ch

Only property creation uses the rotation as an index, so convert the
to figure the index when needed.

v2: Use the new defines to build the _MASK defines (Sean)

Cc: intel-gfx@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: malidp@foss.arm.com
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v1)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1469771405-17653-1-git-send-email-joonas.lahtinen@linux.intel.com

We are only documenting that the read is outside of the lock, and do not
require strict ordering on the operation. In this case the more relaxed
lockless_dereference() will suffice.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466581572-16608-1-git-send-email-chris@chris-wilson.co.uk

There can only be one current master, and it's for the overall device.
Render/control minors don't support master-based auth at all.

This simplifies the master logic a lot, at least in my eyes: All these
additional pointer chases are just confusing.

While doing the conversion I spotted some locking fail:
- drm_lock/drm_auth check dev->master without holding the
  master_mutex. This is fallout from

  commit c996fd0b
  Author: Thomas Hellstrom <thellstrom@vmware.com>
  Date:   Tue Feb 25 19:57:44 2014 +0100

      drm: Protect the master management with a drm_device::master_mutex v3

  but I honestly don't care one bit about those old legacy drivers
  using this.

- debugfs name info should just grab master_mutex.

- And the fbdev helper looked at it to figure out whether someone is
  using KMS. We just need a consistent value, so READ_ONCE. Aside: We
  should probably check if anyone has opened a control node too, but I
  guess current userspace doesn't really do that yet.

v2: Balance locking, reported by Julia.

v3: Rebase on top of Chris' oops fixes.

Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> (v2)
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466499262-18717-1-git-send-email-daniel.vetter@ffwll.ch

Drivers transitioning to atomic might not yet want to enable full
DRIVER_ATOMIC support when it's not entirely working. But using atomic
internally makes a lot more sense earlier.

Instead of spreading such flags to more places I figured it's simpler
to just check for mode_config->funcs->atomic_commit, and use atomic
paths if that is set. For the only driver currently transitioning
(i915) this does the right thing.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-23-git-send-email-daniel.vetter@ffwll.ch

Adapt drm_pick_crtcs() and update_connector_routing() to fallback to
drm_atomic_helper_best_encoder() if funcs->best_encoder() is NULL so
that DRM drivers can leave this hook unassigned if they know they want
to use drm_atomic_helper_best_encoder().

Update the vtables documentation accordingly.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-2-git-send-email-boris.brezillon@free-electrons.com

Change return value to int to propagate errors from gamma_set,
and remove start parameter. Updates always use the full size,
and some drivers even ignore the start parameter altogether.

This is needed for atomic drivers, where an atomic commit can
fail with -EINTR or -ENOMEM and should be restarted. This is already
and issue for drm_atomic_helper_legacy_set_gamma, which this patch
fixes up.

Changes since v1:
- Fix compiler warning. (Emil)
- Fix commit message (Daniel)

Cc: Alex Deucher <alexander.deucher@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Mathieu Larouche <mathieu.larouche@matrox.com>
Cc: Thierry Reding <treding@nvidia.com>
Acked-by: NPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Improve commit message a bit more, mention that this fixes
the helper.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/742944bc-9f41-1acb-df4f-0fd4c8a10168@linux.intel.com

DRM fbdev emulation only supports pallete_color with depth == 8, and
truecolor with depth > 8. Handling depth == 16 for palettes is hence
dead code, let's remove it.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331485-28376-3-git-send-email-daniel.vetter@ffwll.ch

During boot, MST hotplugs are generally expected (even if no physical
hotplugging occurs) and result in DRM's connector topology changing.
This means that using num_connector from the current mode configuration
can lead to the number of connectors changing under us. This can lead to
some nasty scenarios in fbcon:

- We allocate an array to the size of dev->mode_config.num_connectors.
- MST hotplug occurs, dev->mode_config.num_connectors gets incremented.
- We try to loop through each element in the array using the new value
  of dev->mode_config.num_connectors, and end up going out of bounds
  since dev->mode_config.num_connectors is now larger then the array we
  allocated.

fb_helper->connector_count however, will always remain consistent while
we do a modeset in fb_helper.

Note: This is just polish for 4.7, Dave Airlie's drm_connector
refcounting fixed these bugs for real. But it's good enough duct-tape
for stable kernel backporting, since backporting the refcounting
changes is way too invasive.

Cc: stable@vger.kernel.org
Signed-off-by: NLyude <cpaul@redhat.com>
[danvet: Clarify why we need this. Also remove the now unused "dev"
local variable to appease gcc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1463065021-18280-3-git-send-email-cpaul@redhat.com

This was forgotten to fixup in the latest version of the deferred_io
patch which made FB_DEFERRED_IO mandatory.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462982962-10530-2-git-send-email-noralf@tronnes.org

s/modest/modeset/
s/aftert/after/
Signed-off-by: NLyude <cpaul@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462375734-8213-3-git-send-email-cpaul@redhat.com

This takes a reference count when fbdev adds the connector,
and drops it when it removes the connector.

It also drops the now unneeded code to find connectors
and remove the from the modeset as they are reference counted.

v2: drop references when removing all connectors at end.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This adds deferred io support to drm_fb_helper.
The fbdev framebuffer changes are flushed using the callback
(struct drm_framebuffer *)->funcs->dirty() by a dedicated worker
ensuring that it always runs in process context.

For those wondering why we need to be able to handle atomic calling
contexts: Both panic paths and cursor code and fbcon blanking can run
from atomic. See

commit bcb39af4
Author: Dave Airlie <airlied@redhat.com>
Date:   Thu Feb 7 11:19:15 2013 +1000

    drm/udl: make usage as a console safer

for where this was originally discovered.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Augment commit message with why we need to handle atomic
contexts.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-4-git-send-email-noralf@tronnes.org

add_all_connectors doesn't checks whether reallocation is needed, but add_one does.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455540316-17066-2-git-send-email-maarten.lankhorst@linux.intel.com

The fb helper iterates over connectors, using fb_helper->num_connectors
makes it more clear what size the allocations are.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455540316-17066-1-git-send-email-maarten.lankhorst@linux.intel.com

The module_init and module_exit functions will start here, and call the
subsequent init's and exit's.

v10:
 - Keep __init on drm_fb_helper init function.
 - Move MODULE_* macros to the common file.
Signed-off-by: NRafael Antognolli <rafael.antognolli@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/1453417821-2811-2-git-send-email-rafael.antognolli@intel.com

Every new KMS driver writer seems to run into this and wonder how
exactly drm_fb_helper_initial_config can die doing nothing at all.
Set up some big warnings signs around this newbie trap to avoid future
frustration and wasting everyone's time.

v2: Edits from Laurent.

Cc: Carlos Palminha <CARLOS.PALMINHA@synopsys.com>
Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: laurent.pinchart@ideasonboard.com
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453449225-10954-1-git-send-email-daniel.vetter@ffwll.chSigned-off-by: NDaniel Vetter <daniel.vetter@intel.com>

pan_display_atomic() calls drm_atomic_clean_old_fb() to sanitize the
legacy FB fields (plane->fb and plane->old_fb).  However it was building
the plane mask to pass to this function incorrectly (the bitwise OR was
using plane indices rather than plane masks).  The end result was that
sometimes the legacy pointers would become out of sync with the atomic
pointers.  If another operation tried to re-set the same FB onto the
plane, we might end up with the pointers back in sync, but improper
reference counts, which would eventually lead to system crashes when we
accessed a pointer to a prematurely-destroyed FB.

The cause here was a very subtle bug introduced in commit:

        commit 07d3bad6
        Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
        Date:   Wed Nov 11 11:29:11 2015 +0100

            drm/core: Fix old_fb handling in pan_display_atomic.

I found the crashes were most easily reproduced (on i915 at least) by
starting X and then VT switching to a VT that wasn't running a console
instance...the sequence of vt/fbcon entries that happen in that case
trigger a reference count mismatch and crash the system.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93313Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Don't touch plane->old_fb/fb without having the right locks held.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-6-git-send-email-maarten.lankhorst@ubuntu.com

Don't touch plane->old_fb/fb without having the right locks held.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-5-git-send-email-maarten.lankhorst@ubuntu.com

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()..

we've forgotten to do the plane->old_fb refcount dance for
pan_display_atomic, which can result in refcount leaks if the current
configuration is not from fbcon. Which apparently can happen when
vt-switching - fbcon does a pan first before a set_par.

OCD-align function parameters while at it.

v2: Actually git add the OCD.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92483Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445015490-27682-1-git-send-email-daniel.vetter@ffwll.chTested-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The point behind standardizing properties into core drm state
structures is also that internal code looks prettiers. Take advantage
of that and set rotation directly in the fbdev atomic code.

Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445012594-25988-1-git-send-email-daniel.vetter@ffwll.chAcked-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If a driver uses the cursor_set2 crtc callback rather than
cursor_set, use that.  This fixes the fbdev helper for drivers
that use cursor_set2.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Starting with commit

        commit 28cc504e
        Author: Rob Clark <robdclark@gmail.com>
        Date:   Tue Aug 25 15:36:00 2015 -0400

            drm/i915: enable atomic fb-helper

I've been seeing some panics on i915 when the DRM master shuts down that appear
to be caused by using an already-freed framebuffer (i.e., we're unexpectedly
dropping our initial FB's reference count to 0 and freeing it, which causes a
crash when we try to restore it later).  Digging deeper, the state FB
refcounting is working as expected, but we seem to be missing proper
refcounting on the legacy plane->fb pointers in the new atomic fbdev code.

Tracking plane->old_fb and then doing a ref/unref at the end of the
fbdev restore like we do in the legacy ioctl's ensures we don't miscount
references on plane->fb and avoids the panics.

v2 from Daniel:

Really do what the atomic ioctl does:
- Also update plane->fb and plane->crtc.
- Clear out plane->old_fb on failures too.

v3: git add everything. Oops.

v4: Also clear old_fb in all other failure paths, spotted by David.

Cc: Rob Clark <robdclark@gmail.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com> (v1)
Reviewd-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NRob Clark <robdclark@gmail.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>