The functions snd_emu10k1_proc_spdif_read and snd_emu1010_fpga_read
acquire the emu_lock before accessing the FPGA. The function used
to access the FPGA (snd_emu1010_fpga_read) also tries to take
the emu_lock which causes a deadlock.
Remove the outer locking in the proc-functions (guarding only the
already safe fpga read) to prevent this deadlock.

[removed superfluous flags variables too -- tiwai]
Signed-off-by: NMichael Gernoth <michael@gernoth.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Adds an entry for Creative USB X-Fi to the rc_config array in
mixer_quirks.c to allow use of volume knob on the device.
Adds support for newer X-Fi Pro card, known as "Model No. SB1095"
with USB ID "041e:3237"
Signed-off-by: NDmitry M. Fedin <dmitry.fedin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Some BIOS version of Fujitsu Lifebook T731 seems to set up the
headphone pin (0x21) without the assoc number 0x0f while it's set only
to the output on the docking port (0x1a).  With the recent commit
[03ad6a8c: ALSA: hda - Fix "PCM" name being used on one DAC when
 there are two DACs], this resulted in the weird mixer element
mapping where the headphone on the laptop is assigned as a shared
volume with the speaker and the docking port is assigned as an
individual headphone.

This patch improves the situation by correcting the headphone pin
config to the more appropriate value.
Reported-and-tested-by: NTaylor Smock <smocktaylor@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Some M-Audio devices require to receive bootup command just after
powering on, while codes in BeBoB driver doesn't work properly in
big-endian machine because the command should be aligned by
little-endian.

This commit fixes this bug. This fix should go to stable kernel.

Cc: Takayuki Shiroma <t.shiroma.oki@gmail.com>
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Pin sense will active when power pin is wake up.
Power pin will not wake up immediately during resume state.
Add some delay to wait for power pin activated.
Signed-off-by: NKailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Adding this quirk allows us to avoid the noisy
"cannot get freq at ep 0x1" message in dmesg output every time
playback starts.

This ought to affect other Benchmark DAC1 variations using the same
"Microchip Technology, Inc." chip as well, but I have only tested
with the "Pre" variant.
Signed-off-by: NEric Wong <normalperson@yhbt.net>
Cc: Joe Turner <joe@oampo.co.uk>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Dell new platform of ALC256 audio codec.
Support headset mode for Dell ALC256 platform.
Signed-off-by: NKailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Pull ARM SoC fixes from Olof Johansson:
 "The latest and greatest fixes for ARM platform code.  Worth pointing
  out are:

   - Lines-wise, largest is a PXA fix for dealing with interrupts on DT
     that was quite broken.  It's still newish code so while we could
     have held this off, it seemed appropriate to include now

   - Some GPIO fixes for OMAP platforms added a few lines.  This was
     also fixes for code recently added (this release).

   - Small OMAP timer fix to behave better with partially upstreamed
     platforms, which is quite welcome.

   - Allwinner fixes about operating point control, reducing
     overclocking in some cases for better stability.

  plus a handful of other smaller fixes across the map"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: juno: Fix misleading name of UART reference clock
  ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
  ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
  ARM: socfpga: dts: fix spi1 interrupt
  ARM: dts: Fix gpio interrupts for dm816x
  ARM: dts: dra7: remove ti,hwmod property from pcie phy
  ARM: OMAP: dmtimer: disable pm runtime on remove
  ARM: OMAP: dmtimer: check for pm_runtime_get_sync() failure
  ARM: OMAP2+: Fix socbus family info for AM33xx devices
  ARM: dts: omap3: Add missing dmas for crypto
  ARM: dts: rockchip: disable gmac by default in rk3288.dtsi
  MAINTAINERS: add rockchip regexp to the ARM/Rockchip entry
  ARM: pxa: fix pxa interrupts handling in DT
  ARM: pxa: Fix typo in zeus.c
  ARM: sunxi: Have ARCH_SUNXI select RESET_CONTROLLER for clock driver usage

Merge tag 'sunxi-fixes-for-4.0' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into fixes

Allwinner fixes for 4.0

There's a few fixes to merge for 4.0, one to add a select in the machine
Kconfig option to fix a potential build failure, and two fixing cpufreq related
issues.

* tag 'sunxi-fixes-for-4.0' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux:
  ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
  ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
  ARM: sunxi: Have ARCH_SUNXI select RESET_CONTROLLER for clock driver usage
Signed-off-by: NOlof Johansson <olof@lixom.net>

Merge tag 'fixes-v4.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Fixes for omaps for the -rc cycle:

- Fix a device tree based booting vs legacy booting regression for
  omap3 crypto hardware by adding the missing DMA channels.

- Fix /sys/bus/soc/devices/soc0/family for am33xx devices.

- Fix two timer issues that can cause hangs if the timer related
  hwmod data is missing like it often initially is for new SoCs.

- Remove pcie hwmods entry from dts as that causes runtime PM to
  fail for the PHYs.

- A paper bag type dts configuration fix for dm816x GPIO
  interrupts that I just noticed. This is most of the changes
  diffstat wise, but as it's a basic feature for connecting
  devices and things work otherwise, it should be fixed.

* tag 'fixes-v4.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: dts: Fix gpio interrupts for dm816x
  ARM: dts: dra7: remove ti,hwmod property from pcie phy
  ARM: OMAP: dmtimer: disable pm runtime on remove
  ARM: OMAP: dmtimer: check for pm_runtime_get_sync() failure
  ARM: OMAP2+: Fix socbus family info for AM33xx devices
  ARM: dts: omap3: Add missing dmas for crypto
Signed-off-by: NOlof Johansson <olof@lixom.net>

Late fix for v4.0 on the SoCFPGA platform:
- Fix interrupt number for SPI1 interface

* tag 'socfpga_fix_for_v4.0_2' of git://git.rocketboards.org/linux-socfpga-next:
  ARM: socfpga: dts: fix spi1 interrupt
Signed-off-by: NOlof Johansson <olof@lixom.net>

The UART reference clock speed is 7273.8 kHz, not 72738 kHz.

Dots aren't usually used in node names even though ePAPR permits
them.  However, this can easily be avoided by expressing the
frequency in Hz, not kHz.

This patch changes the name to refclk7273800hz, reflecting the
actual clock speed.
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

arm: pxa: fixes for v4.0-rc5

There are only 2 fixes, one for the zeus board about the regulator changes,
where a typo prevented the zeus board from having a working can regulator,
and one regression triggered by the interrupts IRQ shift of 16 affecting all
boards.

* tag 'fixes-for-v4.0-rc5' of https://github.com/rjarzmik/linux:
  ARM: pxa: fix pxa interrupts handling in DT
  ARM: pxa: Fix typo in zeus.c
Signed-off-by: NOlof Johansson <olof@lixom.net>

Pull x86 fix from Ingo Molnar:
 "Fix x86 syscall exit code bug that resulted in spurious non-execution
  of TIF-driven user-return worklets, causing big trouble for things
  like KVM that rely on user notifiers for correctness of their vcpu
  model, causing crashes like double faults"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm/entry: Check for syscall exit work with IRQs disabled

Pull timer fixes from Ingo Molnar:
 "Two clocksource driver fixes, and an idle loop RCU warning fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/sun5i: Fix cpufreq interaction with sched_clock()
  clocksource/drivers: Fix various !CONFIG_HAS_IOMEM build errors
  timers/tick/broadcast-hrtimer: Fix suspicious RCU usage in idle loop

Pull scheduler fix from Ingo Molnar:
 "A single sched/rt corner case fix for RLIMIT_RTIME correctness"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix RLIMIT_RTTIME when PI-boosting to RT

Pull perf fix from Ingo Molnar:
 "A perf kernel side fix for a fuzzer triggered lockup"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix irq_work 'tail' recursion

Pull locking fix from Ingo Molnar:
 "A module unload lockdep race fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix the module unload key range freeing logic

Pull parsic fixes from Helge Deller:
 "One patch from Mikulas fixes a bug on parisc by artifically
  incrementing the counter in pmd_free when the kernel tries to free
  the preallocated pmd.

  Other than that we now prevent that syscalls gets added without
  incrementing __NR_Linux_syscalls and fix the initial pmd setup code
  if a default page size greater than 4k has been selected"

* 'parisc-4.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix pmd code to depend on PT_NLEVELS value, not on CONFIG_64BIT
  parisc: mm: don't count preallocated pmds
  parisc: Add compile-time check when adding new syscalls

Pull kvm ppc bugfixes from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PPC: Book3S HV: Fix instruction emulation
  KVM: PPC: Book3S HV: Endian fix for accessing VPA yield count
  KVM: PPC: Book3S HV: Fix spinlock/mutex ordering issue in kvmppc_set_lpcr()

Pull ARC fixes from Vineet Gupta:
 "We found some issues with signal handling taking down the system.  I
  know its late, but these are important and all marked for stable.

  ARC signal handling related fixes uncovered during recent testing of
  NPTL tools"

* tag 'arc-4.0-fixes-part-2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: signal handling robustify
  ARC: SA_SIGINFO ucontext regs off-by-one

Pull selinux bugfix from James Morris.

Fix broken return value.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selinux: fix sel_write_enforce broken return value

Pull watchdog fixes from Wim Van Sebroeck:

 - mtk_wdt: signedness bug in mtk_wdt_start()

 - imgpdc: Fix NULL pointer dereference during probe and fix the default
   heartbeat

* git://www.linux-watchdog.org/linux-watchdog:
  watchdog: imgpdc: Fix default heartbeat
  watchdog: imgpdc: Fix probe NULL pointer dereference
  watchdog: mtk_wdt: signedness bug in mtk_wdt_start()

Pull sound fixes from Takashi Iwai:
 "Three trivial oneliner fixes for HD-audio.

  Two are device-specific quirks while one is a generic fix for recent
  Realtek codecs"

* tag 'sound-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Add one more node in the EAPD supporting candidate list
  ALSA: hda_intel: apply the Seperate stream_tag for Sunrise Point
  ALSA: hda - Add dock support for Thinkpad T450s (17aa:5036)

The IMG PDC watchdog driver heartbeat module parameter has no default so
it is initialised to zero. This results in the following warning during
probe:

imgpdc-wdt 2006000.wdt: Initial timeout out of range! setting max timeout

The module parameter description implies that the default value should
be PDC_WDT_DEF_TIMEOUT, which isn't yet used, so initialise it to that.

Also tweak the heartbeat module parameter description for consistency.

Fixes: 93937669 ("watchdog: ImgTec PDC Watchdog Timer Driver")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Naidu Tellapati <Naidu.Tellapati@imgtec.com>
Cc: Jude Abraham <Jude.Abraham@imgtec.com>
Cc: linux-watchdog@vger.kernel.org
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

The IMG PDC watchdog probe function calls pdc_wdt_stop() prior to
watchdog_set_drvdata(), causing a NULL pointer dereference when
pdc_wdt_stop() retrieves the struct pdc_wdt_dev pointer using
watchdog_get_drvdata() and reads the register base address through it.

Fix by moving the watchdog_set_drvdata() call earlier, to where various
other pdc_wdt->wdt_dev fields are initialised.

Fixes: 93937669 ("watchdog: ImgTec PDC Watchdog Timer Driver")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Naidu Tellapati <Naidu.Tellapati@imgtec.com>
Cc: Jude Abraham <Jude.Abraham@imgtec.com>
Cc: linux-watchdog@vger.kernel.org
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

"ret" should be signed for the error handling to work correctly.  This
doesn't matter much in real life since mtk_wdt_set_timeout() always
succeeds.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NMatthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Pull drm refcounting fixes from Dave Airlie:
 "Here is the complete set of i915 bug/warn/refcounting fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Fixup legacy plane->crtc link for initial fb config
  drm/i915: Fix atomic state when reusing the firmware fb
  drm/i915: Keep ring->active_list and ring->requests_list consistent
  drm/i915: Don't try to reference the fb in get_initial_plane_config()
  drm: Fixup racy refcounting in plane_force_disable

Pull device mapper fix from Mike Snitzer:
 "Fix DM core device cleanup regression -- due to a latent race that was
  exposed by the bdi changes that were introduced during the 4.0 merge"

* tag 'dm-4.0-fix-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix add_disk() NULL pointer due to race with free_dev()

Merge tag 'linux-kselftest-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fix from Shuah Khan.

* tag 'linux-kselftest-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: Fix build failures when invoked from kselftest target

This should cover the final warnings in -rc5 with two more backports
from our development branch (drm-intel-next-queued). They're the ones
from Daniel and Damien, with references to the reports.

This is on top of drm-fixes because of the dependency on the two earlier
fixes not yet in Linus' tree.

There's an additional regression fix from Chris.

* tag 'drm-intel-fixes-2015-03-26' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Fixup legacy plane->crtc link for initial fb config
  drm/i915: Fix atomic state when reusing the firmware fb
  drm/i915: Keep ring->active_list and ring->requests_list consistent

Pull s390 fixes from Martin Schwidefsky:
 "A couple of bug fixes for s390.

  The ftrace comile fix is quite large for a -rc6 release, but it would
  be nice to have it in 4.0"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/smp: reenable smt after resume
  s390/mm: limit STACK_RND_MASK for compat tasks
  s390/ftrace: fix compile error if CONFIG_KPROBES is disabled
  s390/cpum_sf: add diagnostic sampling event only if it is authorized

This is a very similar bug in the load detect code fixed in

commit 9128b040
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Mar 3 17:31:21 2015 +0100

    drm/i915: Fix modeset state confusion in the load detect code

But this time around it was the initial fb code that forgot to update
the plane->crtc pointer. Otherwise it's the exact same bug, with the
exact same restrains (any set_config call/ioctl that doesn't disable
the pipe papers over the bug for free, so fairly hard to hit in normal
testing). So if you want the full explanation just go read that one
over there - it's rather long ...

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reported-and-tested-by: NJosh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[Jani: backported to drm-intel-fixes for v4.0-rc]
Reference: http://mid.gmane.org/CA+5PVA7ChbtJrknqws1qvZcbrg1CW2pQAFkSMURWWgyASRyGXg@mail.gmail.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

Right now, we get a warning when taking over the firmware fb:

  [drm:drm_atomic_plane_check] FB set but no CRTC

with the following backtrace:

  [<ffffffffa010339d>] drm_atomic_check_only+0x35d/0x510 [drm]
  [<ffffffffa0103567>] drm_atomic_commit+0x17/0x60 [drm]
  [<ffffffffa00a6ccd>] drm_atomic_helper_plane_set_property+0x8d/0xd0 [drm_kms_helper]
  [<ffffffffa00f1fed>] drm_mode_plane_set_obj_prop+0x2d/0x90 [drm]
  [<ffffffffa00a8a1b>] restore_fbdev_mode+0x6b/0xf0 [drm_kms_helper]
  [<ffffffffa00aa969>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper]
  [<ffffffffa00aa9e2>] drm_fb_helper_set_par+0x22/0x50 [drm_kms_helper]
  [<ffffffffa050a71a>] intel_fbdev_set_par+0x1a/0x60 [i915]
  [<ffffffff813ad444>] fbcon_init+0x4f4/0x580

That's because we update the plane state with the fb from the firmware, but we
never associate the plane to that CRTC.

We don't quite have the full DRM take over from HW state just yet, so
fake enough of the plane atomic state to pass the checks.

v2: Fix the state on which we set the CRTC in the case we're sharing the
    initial fb with another pipe. (Matt)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[Jani: backported to drm-intel-fixes for v4.0-rc]
Reference: http://mid.gmane.org/CA+5PVA7yXH=U757w8V=Zj2U1URG4nYNav20NpjtQ4svVueyPNw@mail.gmail.com
Reference: http://lkml.kernel.org/r/CA+55aFweWR=nDzc2Y=rCtL_H8JfdprQiCimN5dwc+TgyD4Bjsg@mail.gmail.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

We have a HP machine which use the codec node 0x17 connecting the
internal speaker, and from the node capability, we saw the EAPD,
if we don't set the EAPD on for this node, the internal speaker
can't output any sound.

Cc: <stable@vger.kernel.org>
BugLink: https://bugs.launchpad.net/bugs/1436745Signed-off-by: NHui Wang <hui.wang@canonical.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The sun5i timer is used as the sched-clock on certain systems, and ever
since we started using cpufreq, the cpu clock (that is one of the
timer's clock indirect parent) now changes as well, along with the
actual sched_clock() rate.

This is not accurate and not desirable.

We can safely remove the sun5i sched-clock on those systems, since we
have other reliable sched_clock() sources in the system.
Tested-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
[ Improved the changelog. ]
Cc: richard@nod.at
Link: http://lkml.kernel.org/r/1427362029-6511-4-git-send-email-daniel.lezcano@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Fix !CONFIG_HAS_IOMEM related build failures in three clocksource drivers.

The build failures have the pattern of:

  drivers/clocksource/sh_cmt.c: In function ‘sh_cmt_map_memory’: drivers/clocksource/sh_cmt.c:920:2:
  error: implicit declaration of function ‘ioremap_nocache’ [-Werror=implicit-function-declaration]   cmt->mapbase = ioremap_nocache(mem->start, resource_size(mem));
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Cc: maxime.ripard@free-electrons.com
Link: http://lkml.kernel.org/r/1427362029-6511-1-git-send-email-daniel.lezcano@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

If we retire requests last, we may use a later seqno and so clear
the requests lists without clearing the active list, leading to
confusion. Hence we should retire requests first for consistency with
the early return. The order used to be important as the lifecycle for
the object on the active list was determined by request->seqno. However,
the requests themselves are now reference counted removing the
constraint from the order of retirement.

Fixes regression from

commit 1b5a433a
Author: John Harrison <John.C.Harrison@Intel.com>
Date:   Mon Nov 24 18:49:42 2014 +0000

    drm/i915: Convert 'i915_seqno_passed' calls into 'i915_gem_request_completed
'

and a

	WARNING: CPU: 0 PID: 1383 at drivers/gpu/drm/i915/i915_gem_evict.c:279 i915_gem_evict_vm+0x10c/0x140()
	WARN_ON(!list_empty(&vm->active_list))

Identified by updating WATCH_LISTS:

	[drm:i915_verify_lists] *ERROR* blitter ring: active list not empty, but no requests
	WARNING: CPU: 0 PID: 681 at drivers/gpu/drm/i915/i915_gem.c:2751 i915_gem_retire_requests_ring+0x149/0x230()
	WARN_ON(i915_verify_lists(ring->dev))

Note that this is only a problem in evict_vm where the following happens
after a retire_request has cleaned out all requests, but not all active
bo:
- intel_ring_idle called from i915_gpu_idle notices that no requests are
  outstanding and immediately returns.
- i915_gem_retire_requests_ring called from i915_gem_retire_requests also
  immediately returns when there's no request, still leaving the bo on the
  active list.
- evict_vm hits the WARN_ON(!list_empty(&vm->active_list)) after evicting
  all active objects that there's still stuff left that shouldn't be
  there.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>