Commit Graph

190 Commits

Author SHA1 Message Date
Boris Brezillon c61b93fe51 drm/atomic: Fix remaining places where !funcs->best_encoder is valid
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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-2-git-send-email-boris.brezillon@free-electrons.com
2016-06-07 16:38:58 +02:00
Maarten Lankhorst 7ea7728387 drm/core: Change declaration for gamma_set.
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: Alex 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: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Improve commit message a bit more, mention that this fixes
the helper.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/742944bc-9f41-1acb-df4f-0fd4c8a10168@linux.intel.com
2016-06-07 15:30:09 +02:00
Daniel Vetter fef1480d0f drm/fb-helper: Remove dead code in setcolreg
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: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331485-28376-3-git-send-email-daniel.vetter@ffwll.ch
2016-05-31 15:24:58 +02:00
Lyude 255f0e7c41 drm/fb_helper: Fix references to dev->mode_config.num_connector
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: Lyude <cpaul@redhat.com>
[danvet: Clarify why we need this. Also remove the now unused "dev"
local variable to appease gcc.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1463065021-18280-3-git-send-email-cpaul@redhat.com
2016-05-17 15:44:41 +02:00
Noralf Trønnes 2dad551cfb drm/fb-helper: Remove mention of CONFIG_FB_DEFERRED_IO in docs
This was forgotten to fixup in the latest version of the deferred_io
patch which made FB_DEFERRED_IO mandatory.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462982962-10530-2-git-send-email-noralf@tronnes.org
2016-05-11 18:47:51 +02:00
Lyude af509d38bb drm/fb_helper: Fix a few typos
s/modest/modeset/
s/aftert/after/

Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462375734-8213-3-git-send-email-cpaul@redhat.com
2016-05-05 09:12:42 +02:00
Dave Airlie 6e86d58be3 drm/fb_helper: add connector reference counting. (v2)
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: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-05-05 12:51:57 +10:00
Noralf Trønnes eaa434defa drm/fb-helper: Add fb_deferred_io support
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 bcb39af448
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: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Augment commit message with why we need to handle atomic
contexts.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-4-git-send-email-noralf@tronnes.org
2016-05-02 16:22:03 +02:00
Maarten Lankhorst 15fce29da3 drm/fb_helper: Use add_one_connector in add_all_connectors.
add_all_connectors doesn't checks whether reallocation is needed, but add_one does.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455540316-17066-2-git-send-email-maarten.lankhorst@linux.intel.com
2016-02-15 14:56:46 +01:00
Maarten Lankhorst 383b2e5711 drm/fb_helper: Use correct allocation count for arrays.
The fb helper iterates over connectors, using fb_helper->num_connectors
makes it more clear what size the allocations are.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455540316-17066-1-git-send-email-maarten.lankhorst@linux.intel.com
2016-02-15 14:54:55 +01:00
Rafael Antognolli 70412cfa6d drm/kms_helper: Add a common place to call init and exit functions.
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: Rafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1453417821-2811-2-git-send-email-rafael.antognolli@intel.com
2016-02-12 14:22:18 +01:00
Daniel Vetter 40f8cf4b5c drm/fbdev-helper: Explain how to debug console_lock fun
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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453449225-10954-1-git-send-email-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-01-25 08:32:22 +01:00
Matt Roper 7118fd9bd9 drm/fb-helper: Use proper plane mask for fb cleanup
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 07d3bad6c1
        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=93313
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 09:54:49 +01:00
Maarten Lankhorst 07d3bad6c1 drm/core: Fix old_fb handling in pan_display_atomic.
Don't touch plane->old_fb/fb without having the right locks held.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-6-git-send-email-maarten.lankhorst@ubuntu.com
2015-11-17 13:02:14 +02:00
Maarten Lankhorst f72c6b33ed drm/core: Fix old_fb handling in restore_fbdev_mode_atomic.
Don't touch plane->old_fb/fb without having the right locks held.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-5-git-send-email-maarten.lankhorst@ubuntu.com
2015-11-17 13:02:14 +02:00
Dave Airlie affa0e033b Merge tag 'topic/drm-misc-2015-10-19' of git://anongit.freedesktop.org/drm-intel into drm-next
More drm-misc for 4.4.
- fb refcount fix in atomic fbdev
- various locking reworks to reduce drm_global_mutex and dev->struct_mutex
- rename docbook to gpu.tmpl and include vga_switcheroo stuff, plus more
  vga_switcheroo (Lukas Wunner)
- viewport check fixes for atomic drivers from Ville
- DRM_DEBUG_VBL from Ville
- non-contentious header fixes from Mikko Rapeli
- small things all over

* tag 'topic/drm-misc-2015-10-19' of git://anongit.freedesktop.org/drm-intel: (31 commits)
  drm/fb-helper: Fix fb refcounting in pan_display_atomic
  drm/fb-helper: Set plane rotation directly
  drm: fix mutex leak in drm_dp_get_mst_branch_device
  drm: Check plane src coordinates correctly during page flip for atomic drivers
  drm: Check crtc viewport correctly with rotated primary plane on atomic drivers
  drm: Refactor plane src coordinate checks
  drm: Swap w/h when converting the mode to src coordidates for a rotated primary plane
  drm: Don't leak fb when plane crtc coodinates are bad
  ALSA: hda - Spell vga_switcheroo consistently
  drm/gem: Use kref_get_unless_zero for the weak mmap references
  drm/vgem: Drop vgem_drm_gem_mmap
  drm: Fix return value of drm_framebuffer_init()
  drm/gem: Use container_of in drm_gem_object_free
  drm/gem: Check locking in drm_gem_object_unreference
  drm/gem: Drop struct_mutex requirement from drm_gem_mmap_obj
  drm/i810_drm.h: include drm/drm.h
  r128_drm.h: include drm/drm.h
  savage_drm.h: include <drm/drm.h>
  gpu/doc: Convert to markdown harder
  gpu/doc: Add vga_switcheroo documentation
  ...
2015-10-20 09:01:49 +10:00
Daniel Vetter a0fb6ad7ae drm/fb-helper: Fix fb refcounting in pan_display_atomic
In

commit bbb1e52402
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=92483
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445015490-27682-1-git-send-email-daniel.vetter@ffwll.ch
Tested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-10-19 11:00:48 +02:00
Daniel Vetter 16e910df19 drm/fb-helper: Set plane rotation directly
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: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445012594-25988-1-git-send-email-daniel.vetter@ffwll.ch
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-10-19 11:00:48 +02:00
Dave Airlie 48f87dd146 Merge commit '06d1ee32a4d25356a710b49d5e95dbdd68bdf505' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Backmerge the drm-fixes pull from Linus's tree into drm-next.

This is to fix some conflicts and make future pulls cleaner
2015-10-16 10:25:28 +10:00
Alex Deucher 03f9abb28c drm: handle cursor_set2 in restore_fbdev_mode
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: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-10-02 15:30:41 +10:00
Matt Roper 942840371c drm/fbdev: Update legacy plane->fb refcounting for atomic restore
Starting with commit

        commit 28cc504e8d
        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: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-09-24 20:14:20 +02:00
Rob Clark 1edf0269f0 drm/fb-helper: atomic pan_display()..
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-09-16 11:39:51 -07:00
Rob Clark bbb1e52402 drm/fb-helper: atomic restore_fbdev_mode()..
Add support for using atomic code-paths for restore_fbdev_mode().

Signed-off-by: Rob Clark <robdclark@gmail.com>
[danvet: Bikeshed comments slightly.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-09-16 11:39:26 -07:00
Daniel Vetter f64c5573d2 drm/fb-helper: Add module option to disable fbdev emulation
Faster than recompiling.

Note that restore_fbdev_mode_unlocked is a bit special and the only
one which returns an error code when fbdev isn't there - i915 needs
that one to not fall over with some additional fbcon related restore
code. Everyone else just ignores the return value or only prints a
DRM_DEBUG level message.

Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-09-08 13:45:50 +02:00
Daniel Vetter b7bdf0a87a drm/fb-helper: Use -errno return in restore_mode_unlocked
Using bool and returning true upon error is very uncommon. Also an int
return value is actually what all the callers which did check it seem
to have expected.

v2: Restore hunk misplaced in a rebase, spotted by Rob.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-09-08 13:45:49 +02:00
Maarten Lankhorst cebbb7396b drm/core: Set mode to NULL when connectors in a set drops to 0.
Without this when a MST connector is removed drm_atomic_helper_set_config
can complain about set->mode && !set->num_connectors.

------------[ cut here ]------------
WARNING: CPU: 2 PID: 2403 at drivers/gpu/drm/drm_atomic_helper.c:1673 drm_atomic_helper_set_config+0x22e/0x420()
CPU: 2 PID: 2403 Comm: kms_flip Not tainted 4.2.0-rc5 #4233
Hardware name: NUC5i7RYB, BIOS RYBDWi35.86A.0246.2015.0309.1355 03/09/2015
 ffffffff81ac75e8 ffff88004e4ffbf8 ffffffff81714c34 0000000080000000
 0000000000000000 ffff88004e4ffc38 ffffffff8107bf81 ffff88004e4ffc48
 ffff8800d8ca0690 ffff8800d8d7a080 ffff8800d8cc2290 ffff8800d07bc9f0
Call Trace:
 [<ffffffff81714c34>] dump_stack+0x4f/0x7b
 [<ffffffff8107bf81>] warn_slowpath_common+0x81/0xc0
 [<ffffffff8107c065>] warn_slowpath_null+0x15/0x20
 [<ffffffff813d9e3e>] drm_atomic_helper_set_config+0x22e/0x420
 [<ffffffff813da174>] ? drm_atomic_helper_plane_set_property+0x84/0xc0
 [<ffffffff813ee101>] drm_mode_set_config_internal+0x61/0x100
 [<ffffffff813dc4ed>] restore_fbdev_mode+0xbd/0xe0
 [<ffffffff813de1e4>] drm_fb_helper_restore_fbdev_mode_unlocked+0x24/0x70
 [<ffffffffc0123d11>] intel_fbdev_restore_mode+0x21/0x80 [i915]
 [<ffffffffc014bf69>] i915_driver_lastclose+0x9/0x10 [i915]
 [<ffffffff813e2429>] drm_lastclose+0x29/0x130
 [<ffffffff813e2844>] drm_release+0x314/0x500
 [<ffffffff81194795>] __fput+0xe5/0x1f0
 [<ffffffff811948d9>] ____fput+0x9/0x10
 [<ffffffff810968d8>] task_work_run+0x88/0xb0
 [<ffffffff8107d53f>] do_exit+0x37f/0xa90
 [<ffffffff8127e258>] ? selinux_file_ioctl+0x48/0xc0
 [<ffffffff81277dfe>] ? security_file_ioctl+0x3e/0x60
 [<ffffffff8107ec80>] do_group_exit+0x40/0xa0
 [<ffffffff8107ecef>] SyS_exit_group+0xf/0x10
 [<ffffffff8171bdd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
---[ end trace 0daf358c49351567 ]---

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-11 12:04:19 +02:00
Geert Uytterhoeven 2c4124fdea drm/fb-helper: Move drm_fb_helper_force_kernel_mode() inside #ifdef
If CONFIG_MAGIC_SYSRQ is not set:

    drivers/gpu/drm/drm_fb_helper.c:390:13: warning: 'drm_fb_helper_force_kernel_mode' defined but not used [-Wunused-function]
     static bool drm_fb_helper_force_kernel_mode(void)
		 ^

Move drm_fb_helper_force_kernel_mode() inside the existing #ifdef to fix
this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:13:08 +02:00
Geert Uytterhoeven 3d9e35a92e drm/fb-helper: Clarify drm_fb_helper_restore_fbdev_mode*()
As of commit 5ea1f752ae ("drm: add
drm_fb_helper_restore_fbdev_mode_unlocked()"),
drm_fb_helper_restore_fbdev_mode() is no longer public, and drivers
should call drm_fb_helper_restore_fbdev_mode_unlocked() from their
->lastclose callbacks instead.

Update the documentation to reflect this, and absorb the one liner
drm_fb_helper_restore_fbdev_mode() into its single caller.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:13:08 +02:00
Daniel Vetter dd908c864d drm/fb-helper: Stop using trylocks in force_restore
Since the panic handling is gone this is only used for force-restoring
the fbdev/fbcon from sysrq, and that's done with a work item. No need
any more to do trylocks, we can just do normal locking.

Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-08-06 14:13:01 +02:00
Daniel Vetter c50bfd08d6 drm/fbdev: Return -EBUSY when oopsing
Trying to do anything with kms drivers when oopsing has become a
failing proposition. But since we can end up in the fbdev code simply
due to the console unblanking that's done unconditionally just
removing our panic handler isn't enough. We need to block all fbdev
callbacks when oopsing.

There was already one in the blank handler, but it failed silently.
That makes it impossible for drivers (like i915) who subclass these
functions to figure this out.

Instead consistently return -EBUSY so that everyone knows that we
really don't want to be bothered right now. This also allows us to
remove a pile of FIXMEs from the i915 fbdev code (since due to the
failure code they now won't attempt to grab dangerous locks any more).

Cc: Dave Airlie <airlied@gmail.com>
Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-08-06 14:13:01 +02:00
Archit Taneja fdefa58a50 drm/fb_helper: Create a wrapper for fb_set_suspend
Some drm drivers call fb_set_suspend. Create a drm_fb_helper function
that wraps around these calls.

This is part of an effort to prevent drm drivers from calling fbdev
functions directly, in order to make fbdev emulation a top level drm
option.

v3:
- Fixed kerneldoc errors

v2:
- Added kerneldocs
- Added a check for non-NULL fb_helper before proceeding. This will
  make the helpers work when we have a module param for fbdev emulation
- Follow the drm way of aligning of arguments in func definitions

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:12:56 +02:00
Archit Taneja 742547b73d drm/fb_helper: Create wrappers for blit, copyarea and fillrect funcs
drm drivers that emulate fbdev populate their fb_fillrect, fb_copyarea
and fb_imageblit fb_ops with the help of cfb_* or sys_* fbdev core
helper functions.

Create drm_fb_helper functions that wrap around these calls.

This is part of an effort to prevent drm drivers from calling fbdev
functions directly, in order to make fbdev emulation a top level drm
option.

v3:
- Fixed kerneldoc errors

v2:
- Added kerneldocs
- Follow the drm way of aligning of arguments in func definitions
- Remove unnecessary checks for non NULL fb_info

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:12:55 +02:00
Archit Taneja cbb1a82e56 drm/fb_helper: Create wrappers for fb_sys_read/write funcs
Some drm drivers populate their fb_ops with fb_sys_read/write fb sysfs
ops.

Create a drm_fb_helper function that wraps around these calls.

This is part of an effort to prevent drm drivers from calling fbdev
functions directly, in order to make fbdev emulation a top level drm
option.

v3:
- Fix kerneldoc errors

v2:
- Added kerneldocs
- Follow the drm way of aligning of arguments in func definitions
- Remove unnecessary checks for non NULL fb_info

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:12:55 +02:00
Archit Taneja 47074ab795 drm/fb_helper: Create a wrapper for unlink_framebuffer
Some drm drivers call unlink_framebuffer. Create a drm_fb_helper function
that wraps around these calls.

This is part of an effort to prevent drm drivers from calling fbdev
functions directly, in order to make fbdev emulation a top level drm
option.

v2:
- Added kerneldocs
- Added a check for non-NULL fb_helper before proceeding. This will
  make the helpers work when we have a module param for fbdev emulation

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:12:54 +02:00
Archit Taneja b8017d6c33 drm/fb_helper: Add drm_fb_helper functions to manage fb_info creation
Every drm driver calls framebuffer_alloc, fb_alloc_cmap,
unregister_framebuffer, fb_dealloc_cmap and framebuffer_release in
order to emulate fbdev support.

Create drm_fb_helper functions that perform the above operations.

This is part of an effort to prevent drm drivers from calling fbdev
functions directly. It also removes repetitive code from drivers.

There are some drivers that call alloc_apertures after framebuffer_alloc
and some that don't. Make the helper always call alloc_apertures. This
would make certain drivers allocate memory for apertures but not use
them. Since it's a small amount of memory, it shouldn't be an issue.

v2:
- Added kerneldocs
- Added a check for non-NULL fb_helper before proceeding. This will
  make the helpers work when we have a module param for fbdev emulation

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-08-06 14:12:54 +02:00
Dave Airlie dcd14dd957 Merge tag 'topic/connector-locking-2015-07-23' of git://anongit.freedesktop.org/drm-intel into drm-next
connector hotplug locking cleanup and fixes to make it save against
atomic. Note that because of depencies this is based on top of the
drm-intel-next pull, so that one needs to go in before this one.

I've also thrown in the mode_group removal on top since it's defunct,
never worked really, no one seems to care and the code can be resurrected
easily.

* tag 'topic/connector-locking-2015-07-23' of git://anongit.freedesktop.org/drm-intel:
  drm: gc now dead mode_group code
  drm: Stop filtering according to mode_group in getresources
  drm: Roll out drm_for_each_{plane,crtc,encoder}
  drm/cma-helper: Fix locking in drm_fb_cma_debugfs_show
  drm: Roll out drm_for_each_connector more
  drm: Amend connector list locking rules
  drm/radeon: Take all modeset locks for DP MST hotplug
  drm/i915: Take all modeset locks for DP MST hotplug
  drm: Check locking in drm_for_each_fb
  drm/i915: Use drm_for_each_fb in i915_debugfs.c
  drm: Check locking in drm_for_each_connector
  drm/fbdev-helper: Grab mode_config.mutex in drm_fb_helper_single_add_all_connectors
  drm/probe-helper: Grab mode_config.mutex in poll_init/enable
  drm: Add modeset object iterators
  drm: Simplify drm_for_each_legacy_plane arguments
2015-07-24 14:30:29 +10:00
Daniel Vetter 169faecadd drm/fbdev-helper: Grab mode_config.mutex in drm_fb_helper_single_add_all_connectors
This is now truly only duct-tape to keep locking checks happy since
calling this function when hpd or polling are already enabled is a
bug. The fbdev helper can't cope with hotplug changes yet at this
point, only after that.

Otoh a bit more robustness in this function can't hurt, and with this
fbdev can actually cope with hotplug changes. And it's also more
consistent with the connector hotadd/remove dp mst needs to do.
Therefore document this as new official behavior.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-07-22 16:25:45 +02:00
Daniel Vetter 6295d607ad drm: Add modeset object iterators
And roll them out across drm_* files. The point here isn't code
prettification (it helps with that too) but that some of these lists
aren't static any more. And having macros will gives us a convenient
place to put locking checks into.

I didn't add an iterator for props since that's only used by a
list_for_each_entry_safe in the driver teardown code.

Search&replace was done with the below cocci spatch. Note that there's
a bunch more places that didn't match and which would need some manual
changes, but I've intentially left these out for this mostly automated
patch.

iterator name drm_for_each_crtc;
struct drm_crtc *crtc;
struct drm_device *dev;
expression head;
@@
- list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+ drm_for_each_crtc (crtc, dev) {
...
}

@@
iterator name drm_for_each_encoder;
struct drm_encoder *encoder;
struct drm_device *dev;
expression head;
@@
- list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+ drm_for_each_encoder (encoder, dev) {
...
}

@@
iterator name drm_for_each_fb;
struct drm_framebuffer *fb;
struct drm_device *dev;
expression head;
@@
- list_for_each_entry(fb, &dev->mode_config.fb_list, head) {
+ drm_for_each_fb (fb, dev) {
...
}

@@
iterator name drm_for_each_connector;
struct drm_connector *connector;
struct drm_device *dev;
expression head;
@@
- list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+ drm_for_each_connector (connector, dev) {
...
}

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-07-22 16:25:45 +02:00
Dave Airlie 6066677cfd drm/fb: drop panic handling
This really doesn't seem to have much chance of working anymore,

esp for irq context, qxl at least tries to talk to the hw,
and waits for irqs, and fails.

with runtime pm and other stuff I think we should just
bail on this for now.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-07-16 11:31:41 +02:00
Jani Nikula be26a66de5 drm/drm: constify all struct drm_*_helper funcs pointers
They are not to be modified.

Generated using the semantic patch:

@@
@@
(
  const struct drm_crtc_helper_funcs *
|
- struct drm_crtc_helper_funcs *
+ const struct drm_crtc_helper_funcs *
)

@@
@@
(
  const struct drm_encoder_helper_funcs *
|
- struct drm_encoder_helper_funcs *
+ const struct drm_encoder_helper_funcs *
)

@@
@@
(
  const struct drm_connector_helper_funcs *
|
- struct drm_connector_helper_funcs *
+ const struct drm_connector_helper_funcs *
)

@@
@@
(
  const struct drm_plane_helper_funcs *
|
- struct drm_plane_helper_funcs *
+ const struct drm_plane_helper_funcs *
)

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-04-07 18:11:25 +02:00
Daniel Stone f3af5c7ddd drm: fb_helper: Simplify exit condition
mode is always NULL at this point in the function, so make our intention
clear.

Signed-off-by: Daniel Stone <daniels@collabora.com>
[danvet: Stop clearing mode too to enlist gcc in tracking
uninitialized usage. And remove a space while at it.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-03-23 16:22:29 +01:00
Rob Clark 0e3704c94c drm/fb: handle tiled connectors better
We don't want tile 0,0 to artificially constrain the size of the legacy
fbdev device.  Instead when reducing fb_size to be the minimum of all
displays, only consider the rightmost and bottommost tiles.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Tested-by: Hai Li <hali@codeaurora.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-03-11 22:10:11 +01:00
Rob Clark 675c8328db drm/fb: small cleanup
Flip conditional to reduce indentation level of rest of fxn, and use
min/max to make the code clearer.

v2: surface_width -> surface_height typo

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-03-11 22:09:39 +01:00
Linus Torvalds 796e1c5571 Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
 "This is the main drm pull, it has a shared branch with some alsa
  crossover but everything should be acked by relevant people.

  New drivers:
     - ATMEL HLCDC driver
     - designware HDMI core support (used in multiple SoCs).

  core:
     - lots more atomic modesetting work, properties and atomic ioctl
       (hidden under option)
     - bridge rework allows support for Samsung exynos chromebooks to
       work finally.
     - some more panels supported

  i915:
     - atomic plane update support
     - DSI uses shared DSI infrastructure
     - Skylake basic support is all merged now
     - component framework used for i915/snd-hda interactions
     - write-combine cpu memory mappings
     - engine init code refactored
     - full ppgtt enabled where execlists are enabled.
     - cherryview rps/gpu turbo and pipe CRC support.

  radeon:
     - indirect draw support for evergreen/cayman
     - SMC and manual fan control for SI/CI
     - Displayport audio support

  amdkfd:
     - SDMA usermode queue support
     - replace suballocator usage with more suitable one
     - rework for allowing interfacing to more than radeon

  nouveau:
     - major renaming in prep for later splitting work
     - merge arm platform driver into nouveau
     - GK20A reclocking support

  msm:
     - conversion to atomic modesetting
     - YUV support for mdp4/5
     - eDP support
     - hw cursor for mdp5

  tegra:
     - conversion to atomic modesetting
     - better suspend/resume support for child devices

  rcar-du:
     - interlaced support

  imx:
     - move to using dw_hdmi shared support
     - mode_fixup support

  sti:
     - DVO support
     - HDMI infoframe support

  exynos:
     - refactoring and cleanup, removed lots of internal unnecessary
       abstraction
     - exynos7 DECON display controller support

  Along with the usual bunch of fixes, cleanups etc"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (724 commits)
  drm/radeon: fix voltage setup on hawaii
  drm/radeon/dp: Set EDP_CONFIGURATION_SET for bridge chips if necessary
  drm/radeon: only enable kv/kb dpm interrupts once v3
  drm/radeon: workaround for CP HW bug on CIK
  drm/radeon: Don't try to enable write-combining without PAT
  drm/radeon: use 0-255 rather than 0-100 for pwm fan range
  drm/i915: Clamp efficient frequency to valid range
  drm/i915: Really ignore long HPD pulses on eDP
  drm/exynos: Add DECON driver
  drm/i915: Correct the base value while updating LP_OUTPUT_HOLD in MIPI_PORT_CTRL
  drm/i915: Insert a command barrier on BLT/BSD cache flushes
  drm/i915: Drop vblank wait from intel_dp_link_down
  drm/exynos: fix NULL pointer reference
  drm/exynos: remove exynos_plane_dpms
  drm/exynos: remove mode property of exynos crtc
  drm/exynos: Remove exynos_plane_dpms() call with no effect
  drm/i915: Squelch overzealous uncore reset WARN_ON
  drm/i915: Take runtime pm reference on hangcheck_info
  drm/i915: Correct the IOSF Dev_FN field for IOSF transfers
  drm/exynos: fix DMA_ATTR_NO_KERNEL_MAPPING usage
  ...
2015-02-16 15:48:00 -08:00
Rob Clark 2148f18fdb drm: fix fb-helper vs MST dangling connector ptrs (v2)
VT switch back/forth from console to xserver (for example) has potential
to go horribly wrong if a dynamic DP MST connector ends up in the saved
modeset that is restored when switching back to fbcon.

When removing a dynamic connector, don't forget to clean up the saved
state.

v1: original
v2: null out set->fb if no more connectors to avoid making i915 cranky

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1184968
Cc: stable@vger.kernel.org #v3.17+
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-01-30 13:04:17 +10:00
Dave Airlie e4514003c6 Merge tag 'topic/core-stuff-2015-01-23' of git://anongit.freedesktop.org/drm-intel into drm-next
Just flushing out my drm-misc branch, nothing major. Well too old patches
I've dug out from years since a patch from Rob look eerily familiar ;-)

* tag 'topic/core-stuff-2015-01-23' of git://anongit.freedesktop.org/drm-intel:
  drm/probe-helper: clamp unknown connector status in the poll work
  drm/probe-helper: don't lose hotplug event
  next: drm/atomic: Use copy_from_user to copy 64 bit data from user space
  drm: Make drm_read() more robust against multithreaded races
  drm/fb-helper: Propagate errors from initial config failure
  drm: Drop superfluous "select VT_HW_CONSOLE_BINDING"
2015-01-27 08:54:11 +10:00
Thierry Reding 01934c2a69 drm/fb-helper: Propagate errors from initial config failure
Make drm_fb_helper_initial_config() return an int rather than a bool so
that the error can be properly propagated. While at it, update drivers
to propagate errors further rather than just ignore them.

v2:
- cirrus: No cleanup is required, the top-level cirrus_driver_load()
  will do it as part of cirrus_driver_unload() in its cleanup path.
  Reported-by: Fengguang Wu <fengguang.wu@intel.com>

Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
[danvet: Squash in simplification patch from kbuild.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-01-21 14:57:03 +01:00
Rui Wang 9aa609e1a3 drm: fb helper should avoid sleeping in panic context
There are still some places in the fb helper that need to avoid
sleeping in panic context. Here's an example:

[   65.615496] bad: scheduling from the idle thread!
[   65.620747] CPU: 92 PID: 0 Comm: swapper/92 Tainted: G   M        E  3.18.0-rc4-7-default+ #20

[   65.630364] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS
BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
[   65.641923]  ffff88087f693d80 ffff88087f689878 ffffffff81566db9 0000000000000000
[   65.650226]  ffff88087f693d80 ffff88087f689898 ffffffff810871ff ffff88046eb3e0d0
[   65.658527]  ffff88087f693d80 ffff88087f6898c8 ffffffff8107c1fa 000000017f6898b8
[   65.666830] Call Trace:
[   65.669557]  <#MC>  [<ffffffff81566db9>] dump_stack+0x46/0x58
[   65.675994]  [<ffffffff810871ff>] dequeue_task_idle+0x2f/0x40
[   65.682412]  [<ffffffff8107c1fa>] dequeue_task+0x5a/0x80
[   65.688345]  [<ffffffff810804f3>] deactivate_task+0x23/0x30
[   65.694569]  [<ffffffff81569050>] __schedule+0x580/0x7f0
[   65.700502]  [<ffffffff81569739>] schedule_preempt_disabled+0x29/0x70
[   65.707696]  [<ffffffff8156abb6>] __ww_mutex_lock_slowpath+0xb8/0x162
[   65.714891]  [<ffffffff8156acb3>] __ww_mutex_lock+0x53/0x85
[   65.721125]  [<ffffffffa00b3a5d>] drm_modeset_lock+0x3d/0x110 [drm]
[   65.728132]  [<ffffffffa00b3c2a>] __drm_modeset_lock_all+0x8a/0x120 [drm]
[   65.735721]  [<ffffffffa00b3cd0>] drm_modeset_lock_all+0x10/0x30 [drm]
[   65.743015]  [<ffffffffa01af8bf>] drm_fb_helper_pan_display+0x2f/0xf0 [drm_kms_helper]
[   65.751857]  [<ffffffff8132bd21>] fb_pan_display+0xd1/0x1a0
[   65.758081]  [<ffffffff81326010>] bit_update_start+0x20/0x50
[   65.764400]  [<ffffffff813259f2>] fbcon_switch+0x3a2/0x550
[   65.770528]  [<ffffffff813a01c9>] redraw_screen+0x189/0x240
[   65.776750]  [<ffffffff81322f8a>] fbcon_blank+0x20a/0x2d0
[   65.782778]  [<ffffffff8137d359>] ? erst_writer+0x209/0x330
[   65.789002]  [<ffffffff810ba2f3>] ? internal_add_timer+0x63/0x80
[   65.795710]  [<ffffffff810bc137>] ? mod_timer+0x127/0x1e0
[   65.801740]  [<ffffffff813a0cd8>] do_unblank_screen+0xa8/0x1d0
[   65.808255]  [<ffffffff813a0e10>] unblank_screen+0x10/0x20
[   65.814381]  [<ffffffff812ca0d9>] bust_spinlocks+0x19/0x40
[   65.820508]  [<ffffffff81561ca7>] panic+0x106/0x1f5
[   65.825955]  [<ffffffff8102336c>] mce_panic+0x2ac/0x2e0
[   65.831789]  [<ffffffff812c796a>] ? delay_tsc+0x4a/0x80
[   65.837625]  [<ffffffff81024e1f>] do_machine_check+0xbaf/0xbf0
[   65.844138]  [<ffffffff813365d7>] ? intel_idle+0xc7/0x150
[   65.850166]  [<ffffffff8156f03f>] machine_check+0x1f/0x30
[   65.856195]  [<ffffffff813365d7>] ? intel_idle+0xc7/0x150
[   65.862222]  <<EOE>>  [<ffffffff814283d5>] cpuidle_enter_state+0x55/0x170
[   65.869823]  [<ffffffff814285a7>] cpuidle_enter+0x17/0x20
[   65.875852]  [<ffffffff81097b08>] cpu_startup_entry+0x2d8/0x370
[   65.882467]  [<ffffffff8102fe29>] start_secondary+0x159/0x180

There's __drm_modeset_lock_all() which Daniel Vetter introduced for this
purpose. We can leverage that without reinventing anything. This patch
works with the latest kernel.

Reviewed-by: Rob Clark <robdclark@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-01-21 09:26:15 +10:00
Dave Airlie b0ee9e7fa5 drm/fb: add support for tiled monitor configurations. (v2)
This adds fbdev/con support for tiled monitors, so that we
only set a mode on the correct half of the monitor, or
span the two halves if needed.

v2: remove unneeded ERROR, fix | vs ||

Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-12-09 09:56:49 +10:00
Dave Airlie e2809c7db8 drm/fb_helper: move deferred fb checking into restore mode (v2)
On MST systems the monitors don't appear when we set the fb up,
but plymouth opens the drm device and holds it open while they
come up, when plymouth finishes and lastclose gets called we
don't do the delayed fb probe, so the monitor never appears on the
console.

Fix this by moving the delayed checking into the mode restore.

v2: Daniel suggested that ->delayed_hotplug is set under
the mode_config mutex, so we should check it under that as
well, while we are in the area.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-12-09 09:56:45 +10:00