Add a new Kconfig option to enable/disable the extra warnings
from the vblank evade code. For now we'll keep the warning
about an actually missed vblank always enabled as that can have
an actual user visible impact. But if we miss the deadline
othrwise there's no real need to bother the user with that.
We'll want these warnings enabled during development however
so that we can catch regressions.

Based on the reports it looks like this is still very easy
to hit on SKL, so we have more work ahead of us to optimize
the crtiical section further.

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reported-by: Jens Axboe <axboe@kernel.dk>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: e1edbd44e23b ("drm/i915: Complain if we take too long under vblank evasion.")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Quite a few patches, but not much code changed:
- Fixes regression from atomic when only the source rect of a plane
changes (ie. xrandr --right-of)
- Fixes another issue where atomic changed behaviour underneath us,
potentially causing laggy cursor position updates
- Fixes for a bunch of races in thermal code, which lead to random
lockups for a lot of users

* 'linux-4.12' of git://github.com/skeggsb/linux:
  drm/nouveau/therm: remove ineffective workarounds for alarm bugs
  drm/nouveau/tmr: avoid processing completed alarms when adding a new one
  drm/nouveau/tmr: fix corruption of the pending list when rescheduling an alarm
  drm/nouveau/tmr: handle races with hw when updating the next alarm time
  drm/nouveau/tmr: ack interrupt before processing alarms
  drm/nouveau/core: fix static checker warning
  drm/nouveau/fb/ram/gf100-: remove 0x10f200 read
  drm/nouveau/kms/nv50: skip core channel cursor update on position-only changes
  drm/nouveau/kms/nv50: fix source-rect-only plane updates
  drm/nouveau/kms/nv50: remove pointless argument to window atomic_check_acquire()

Fixes for 4.12.  This is a bit bigger than usual since it's 3 weeks
worth of fixes and most of these changes are for vega10 which is
new for 4.12 and still in a fair amount of flux.  It looks like
you missed my last pull request, so those patches are included here
as well.  Highlights:
- Lots of vega10 fixes
- Fix interruptable wait mixup
- Fan control method fixes
- Misc display fixes for radeon and amdgpu
- Misc bug fixes

* 'drm-next-4.12' of git://people.freedesktop.org/~agd5f/linux: (132 commits)
  drm/amd/powerplay: refine pwm1_enable callback functions for CI.
  drm/amd/powerplay: refine pwm1_enable callback functions for vi.
  drm/amd/powerplay: refine pwm1_enable callback functions for Vega10.
  drm/amdgpu: refine amdgpu pwm1_enable sysfs interface.
  drm/amdgpu: add amd fan ctrl mode enums.
  drm/amd/powerplay: add more smu message on Vega10.
  drm/amdgpu: fix dependency issue
  drm/amd: fix init order of sched job
  drm/amdgpu: add some additional vega10 pci ids
  drm/amdgpu/soc15: use atomfirmware for setting bios scratch for reset
  drm/amdgpu/atomfirmware: add function to update engine hang status
  drm/radeon: only warn once in radeon_ttm_bo_destroy if va list not empty
  drm/amdgpu: fix mutex list null pointer reference
  drm/amd/powerplay: fix bug sclk/mclk level can't be set on vega10.
  drm/amd/powerplay: Setup sw CTF to allow graceful exit when temperature exceeds maximum.
  drm/amd/powerplay: delete dead code in powerplay.
  drm/amdgpu: Use less generic enum definitions
  drm/amdgpu/gfx9: derive tile pipes from golden settings
  drm/amdgpu/gfx: drop max_gs_waves_per_vgt
  drm/amd/powerplay: disable engine spread spectrum feature on Vega10.
  ...

Core Changes:
- Add quirk for LGD 764 panel to default 10bpc (Mario)

Cc: Mario Kleiner <mario.kleiner.de@gmail.com>

* tag 'drm-misc-next-fixes-2017-05-05' of git://anongit.freedesktop.org/git/drm-misc:
  drm/edid: Add 10 bpc quirk for LGD 764 panel in HP zBook 17 G2

These were ineffective due to touching the list without the alarm lock,
but should no longer be required.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org

The idea here was to avoid having to "manually" program the HW if there's
a new earliest alarm.  This was lazy and bad, as it leads to loads of fun
races between inter-related callers (ie. therm).

Turns out, it's not so difficult after all.  Go figure ;)

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org

At least therm/fantog "attempts" to work around this issue, which could
lead to corruption of the pending alarm list.

Fix it properly by not updating the timestamp without the lock held, or
trying to add an already pending alarm to the pending alarm list....

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org

If the time to the next alarm is short enough, we could race with HW and
end up with an ~4 second delay until it triggers.

Fix this by checking again after we update HW.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org

Fixes a race where we can miss an alarm that triggers while we're already
processing previous alarms.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org

object->engine cannot be NULL, it's either valid, or an error pointer.

This particular condition shouldn't actually be possible, but just in
case, we'll keep it.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>